GMPLS

Generalized Multiprotocol Label Switching (GMPLS) control allows each network element (NE) to perform local resource discovery, routing, and signaling in a distributed manner.

The advancement of software-defined transport networking technology enables a group of NEs to be managed through centralized controller hierarchies. This helps to tackle challenges arising from multiple domains, vendors, and technologies. An example of such a centralized architecture is the Abstraction and Control of Traffic-Engineered Networks (ACTN) controller hierarchy, as described in RFC 8453.

Both the distributed and centralized control planes have their respective advantages and should complement each other in the system, rather than compete. This document outlines how the GMPLS distributed control plane can work together with a centralized controller system in a transport network.

This document defines a YANG data model to describe microwave and millimeter-wave radio links in a network topology.

The Path Computation Element Communication Protocol (PCEP) has been extended to support stateful PCE functions where the stateful PCE maintains information about paths and resource usage within a network; however, these extensions do not cover all requirements for GMPLS networks.

This document provides the extensions required for PCEP so as to enable the usage of a stateful PCE capability in GMPLS-controlled networks.

This document examines the applicability of using existing GMPLS routing and signaling mechanisms to set up Optical Data Unit-k (ODUk) Label Switched Paths (LSPs) over Optical Data Unit-Cn (ODUCn) links as defined in the 2020 version of ITU-T Recommendation G.709.

This document describes extensions to the Intermediate System to Intermediate System (IS-IS) protocol to support Multiprotocol Label Switching (MPLS) and Generalized MPLS (GMPLS) Traffic Engineering (TE) for multiple Autonomous Systems (ASes). It defines IS-IS extensions for the flooding of TE information about inter-AS links, which can be used to perform inter-AS TE path computation.

No support for flooding information from within one AS to another AS is proposed or defined in this document.

This document builds on RFC 5316 by adding support for IPv6-only operation.

This document obsoletes RFC 5316.

ITU-T Recommendation G.808.3 defines the generic aspects of a Shared Mesh Protection (SMP) mechanism, where the difference between SMP and Shared Mesh Restoration (SMR) is also identified. ITU-T Recommendation G.873.3 defines the protection switching operation and associated protocol for SMP at the Optical Data Unit (ODU) layer. RFC 7412 provides requirements for any mechanism that would be used to implement SMP in a Multi-Protocol Label Switching - Transport Profile (MPLS-TP) network.

This document updates RFCs 4872 and 4873 to provide extensions for Generalized Multi-Protocol Label Switching (GMPLS) signaling to support the control of the SMP mechanism.

This document defines a collection of common data types and groupings in the YANG data modeling language. These derived common types and groupings are intended to be imported by modules that model Layer 0 optical Traffic Engineering (TE) configuration and state capabilities such as Wavelength Switched Optical Networks (WSONs) and flexi-grid Dense Wavelength Division Multiplexing (DWDM) networks.

This document provides a YANG data model for the routing and wavelength assignment (RWA) TE topology in Wavelength Switched Optical Networks (WSONs). The YANG data model defined in this document conforms to the Network Management Datastore Architecture (NMDA).

A Path Computation Element (PCE) provides path computation functions for Multiprotocol Label Switching (MPLS) and Generalized MPLS (GMPLS) networks. Additional requirements for GMPLS are identified in RFC 7025.

This memo provides extensions to the Path Computation Element Communication Protocol (PCEP) for the support of the GMPLS control plane to address those requirements.

This document provides Path Computation Element Communication Protocol (PCEP) extensions for the support of Routing and Wavelength Assignment (RWA) in Wavelength Switched Optical Networks (WSONs). Path provisioning in WSONs requires an RWA process. From a path computation perspective, wavelength assignment is the process of determining which wavelength can be used on each hop of a path and forms an additional routing constraint to optical path computation.

The Path Computation Element (PCE) may be used for computing services that traverse multi-area and multi-Autonomous System (multi-AS) Multiprotocol Label Switching (MPLS) and Generalized MPLS (GMPLS) Traffic-Engineered (TE) networks.

This document examines the applicability of the PCE architecture, protocols, and protocol extensions for computing multi-area and multi-AS paths in MPLS and GMPLS networks.

This document defines a YANG module for alarm management. It includes functions for alarm-list management, alarm shelving, and notifications to inform management systems. There are also operations to manage the operator state of an alarm and administrative alarm procedures. The module carefully maps to relevant alarm standards.

A packet-switching network may contain links with variable bandwidths (e.g., copper and radio). The bandwidth of such links is sensitive to the external environment (e.g., climate). Availability is typically used to describe these links when doing network planning. This document introduces an optional Bandwidth Availability TLV in RSVP-TE signaling. This extension can be used to set up a GMPLS Label Switched Path (LSP) in conjunction with the Ethernet SENDER_TSPEC object.

This document defines a YANG data model for control and management of radio link interfaces and their connectivity to packet (typically Ethernet) interfaces in a microwave/millimeter wave node. The data nodes for management of the interface protection functionality is broken out into a separate and generic YANG data model in order to make it available for other interface types as well.

The unification of control and management of microwave radio link interfaces is a precondition for seamless multi-layer networking and automated network provisioning and operation.

This document describes the required characteristics and use cases for control and management of radio link interface parameters using a YANG data model.

The purpose is to create a framework to identify the necessary information elements and define a YANG data model for control and management of the radio link interfaces in a microwave node. Some parts of the resulting model may be generic and could also be used by other technologies, e.g., Ethernet technology.

The International Telecommunication Union Telecommunication standardization sector (ITU-T) has extended its Recommendations G.694.1 and G.872 to include a new Dense Wavelength Division Multiplexing (DWDM) grid by defining channel spacings, a set of nominal central frequencies, and the concept of the "frequency slot". Corresponding techniques for data-plane connections are known as "flexi-grid".

Based on the characteristics of flexi-grid defined in G.694.1 and in RFCs 7698 and 7699, this document describes the Open Shortest Path First - Traffic Engineering (OSPF-TE) extensions in support of GMPLS control of networks that include devices that use the new flexible optical grid.

A network may contain links with variable discrete bandwidth, e.g., microwave and copper. The bandwidth of such links may change discretely in response to a changing external environment. The word "availability" is typically used to describe such links during network planning. This document defines a new type of Generalized Switching Capability-Specific Information (SCSI) TLV to extend the Generalized Multiprotocol Label Switching (GMPLS) Open Shortest Path First (OSPF) routing protocol. The extension can be used for route computation in a network that contains links with variable discrete bandwidth. Note that this document only covers the mechanisms by which the availability information is distributed. The mechanisms by which availability information of a link is determined and the use of the distributed information for route computation are outside the scope of this document. It is intended that technology-specific documents will reference this document to describe specific uses.

The Path Computation Element (PCE) provides path computation functions in support of traffic engineering in Multiprotocol Label Switching (MPLS) and Generalized MPLS (GMPLS) networks.

MPLS and GMPLS networks may be constructed from layered service networks. It is advantageous for overall network efficiency to provide end-to-end traffic engineering across multiple network layers through a process called inter-layer traffic engineering. PCE is a candidate solution for such requirements.

The PCE Communication Protocol (PCEP) is designed as a communication protocol between Path Computation Clients (PCCs) and PCEs. This document presents PCEP extensions for inter-layer traffic engineering.

This document updates the Resource Reservation Protocol - Traffic Engineering (RSVP-TE) Fast Reroute (FRR) procedures defined in RFC 4090 to support Packet Switch Capable (PSC) Generalized Multiprotocol Label Switching (GMPLS) Label Switched Paths (LSPs). These updates allow the coordination of a bidirectional bypass tunnel assignment protecting a common facility in both forward and reverse directions of a co-routed bidirectional LSP. In addition, these updates enable the redirection of bidirectional traffic onto bypass tunnels that ensure the co-routing of data paths in the forward and reverse directions after FRR and avoid RSVP soft-state timeout in the control plane.

This document defines a generic information structure for information carried in routing protocol Interface Switching Capability Descriptor (ISCD) Switching Capability Specific Information (SCSI) fields. This "Generalized SCSI" can be used with routing protocols that define GMPLS ISCDs and any specific technology. This document does not modify any existing technology-specific formats and is defined for use in conjunction with new GMPLS Switching Capability types. The context for this document is Generalized MPLS, and the reader is expected to be familiar with the GMPLS architecture and associated protocol standards.

In non-packet transport networks, there are requirements where the Generalized Multiprotocol Label Switching (GMPLS) end-to-end recovery scheme needs to employ a restoration Label Switched Path (LSP) while keeping resources for the working and/or protecting LSPs reserved in the network after the failure occurs.

This document reviews how the LSP association is to be provided using Resource Reservation Protocol - Traffic Engineering (RSVP-TE) signaling in the context of a GMPLS end-to-end recovery scheme when using restoration LSP where failed LSP is not torn down. In addition, this document discusses resource sharing-based setup and teardown of LSPs as well as LSP reversion procedures. No new signaling extensions are defined by this document, and it is strictly informative in nature.

Multiprotocol Label Switching (MPLS) is being extended to the edge of operator networks including the network access nodes. Separately, network access nodes such as Passive Optical Network (PON) Optical Line Terminations (OLTs) have evolved to support first-mile access protection, where one or more physical OLTs provide first-mile diversity to the customer edge. Multihoming support is needed on the MPLS-enabled PON OLT to provide resiliency for provided services. This document describes the Multi-Chassis PON (MC-PON) protection architecture in MPLS and also specifies the Inter-Chassis Communication Protocol (ICCP) extension to support it.

RFCs 4328 and 7139 provide signaling extensions in Resource ReserVation Protocol - Traffic Engineering (RSVP-TE) to control the full set of Optical Transport Network (OTN) features. However, these specifications do not cover the additional Optical channel Data Unit (ODU) containers defined in G.Sup43 (ODU1e, ODU3e1, and ODU3e2). This document defines new Signal Types for these additional containers.

IANA defined the "OTN Signal Type" subregistry of the "Generalized Multi-Protocol Label Switching (GMPLS) Signaling Parameters" registry in RFC 7139. This document updates the "OTN Signal Type" subregistry to allow registration via Specification Required.

This memo describes the extensions to the Resource Reservation Protocol - Traffic Engineering (RSVP-TE) signaling protocol to support Label Switched Paths (LSPs) in a GMPLS-controlled network that includes devices using the flexible optical grid.

To allow efficient allocation of optical spectral bandwidth for systems that have high bit-rates, the International Telecommunication Union Telecommunication Standardization Sector (ITU-T) has extended its Recommendations G.694.1 and G.872 to include a new Dense Wavelength Division Multiplexing (DWDM) grid by defining a set of nominal central frequencies, channel spacings, and the concept of the "frequency slot". In such an environment, a data-plane connection is switched based on allocated, variable-sized frequency ranges within the optical spectrum, creating what is known as a flexible grid (flexi-grid).

Given the specific characteristics of flexi-grid optical networks and their associated technology, this document defines a framework and the associated control-plane requirements for the application of the existing GMPLS architecture and control-plane protocols to the control of flexi-grid DWDM networks. The actual extensions to the GMPLS protocols will be defined in companion documents.

GMPLS supports the description of optical switching by identifying entries in fixed lists of switchable wavelengths (called grids) through the encoding of lambda labels. Work within the ITU-T Study Group 15 has defined a finer-granularity grid, and the facility to flexibly select different widths of spectrum from the grid. This document defines a new GMPLS lambda label format to support this flexi-grid.

This document updates RFCs 3471 and 6205 by introducing a new label format.

This document provides Generalized Multiprotocol Label Switching (GMPLS) Open Shortest Path First (OSPF) routing enhancements to support signal compatibility constraints associated with Wavelength Switched Optical Network (WSON) elements. These routing enhancements are applicable in common optical or hybrid electro-optical networks where not all the optical signals in the network are compatible with all network elements participating in the network.

This compatibility constraint model is applicable to common optical or hybrid electro-optical systems such as optical-electronic-optical (OEO) switches, regenerators, and wavelength converters, since such systems can be limited to processing only certain types of WSON signals.

This document provides extensions to Generalized Multiprotocol Label Switching (GMPLS) signaling for control of Wavelength Switched Optical Networks (WSONs). Such extensions are applicable in WSONs under a number of conditions including: (a) when optional processing, such as regeneration, must be configured to occur at specific nodes along a path, (b) where equipment must be configured to accept an optical signal with specific attributes, or (c) where equipment must be configured to output an optical signal with specific attributes. This document provides mechanisms to support distributed wavelength assignment with a choice of distributed wavelength assignment algorithms.

Establishment and control of Label Switch Paths (LSPs) have become mainstream tools of commercial and government network providers. One of the elements of further evolving such networks is scaling their performance in terms of LSP bandwidth and traffic loads, LSP intensity (e.g., rate of LSP creation, deletion, and modification), LSP set up delay, quality-of-service differentiation, and different levels of resilience.

The goal of this document is to present target scaling objectives and the related protocol requirements for Generalized Multi-Protocol Label Switching (GMPLS).

RFC 5420 extends RSVP-TE to specify or record generic attributes that apply to the whole of the path of a Label Switched Path (LSP). This document defines an extension to the RSVP Explicit Route Object (ERO) and Record Route Object (RRO) to allow them to specify or record generic attributes that apply to a given hop.

This document specifies extensions to Resource Reservation Protocol - Traffic Engineering (RSVP-TE) to support Lock Instruct (LI) and Loopback (LB) mechanisms for Label Switched Paths (LSPs). These mechanisms are applicable to technologies that use Generalized MPLS (GMPLS) for the control plane.

Generalized Multiprotocol Label Switching (GMPLS) can be used to control a wide variety of technologies. In some of these technologies, network elements and links may impose additional routing constraints such as asymmetric switch connectivity, non-local label assignment, and label range limitations on links.

This document provides efficient, protocol-agnostic encodings for general information elements representing connectivity and label constraints as well as label availability. It is intended that protocol-specific documents will reference this memo to describe how information is carried for specific uses.

Generalized Multiprotocol Label Switching (GMPLS) can be used to control a wide variety of technologies including packet switching (e.g., MPLS), time division (e.g., Synchronous Optical Network / Synchronous Digital Hierarchy (SONET/SDH) and Optical Transport Network (OTN)), wavelength (lambdas), and spatial switching (e.g., incoming port or fiber to outgoing port or fiber). In some of these technologies, network elements and links may impose additional routing constraints such as asymmetric switch connectivity, non- local label assignment, and label range limitations on links. This document describes Open Shortest Path First (OSPF) routing protocol extensions to support these kinds of constraints under the control of GMPLS.

A Wavelength Switched Optical Network (WSON) requires certain key information fields be made available to facilitate path computation and the establishment of Label Switched Paths (LSPs). The information model described in "Routing and Wavelength Assignment Information Model for Wavelength Switched Optical Networks" (RFC 7446) shows what information is required at specific points in the WSON. Part of the WSON information model contains aspects that may be of general applicability to other technologies, while other parts are specific to WSONs.

This document provides efficient, protocol-agnostic encodings for the WSON-specific information fields. It is intended that protocol- specific documents will reference this memo to describe how information is carried for specific uses. Such encodings can be used to extend GMPLS signaling and routing protocols. In addition, these encodings could be used by other mechanisms to convey this same information to a Path Computation Element (PCE).

This specification describes the configuration of proactive MPLS Transport Profile (MPLS-TP) Operations, Administration, and Maintenance (OAM) functions for a given Label Switched Path (LSP) using a set of TLVs that are carried by the GMPLS RSVP-TE protocol based on the OAM Configuration Framework for GMPLS RSVP-TE.

This document provides a model of information needed by the Routing and Wavelength Assignment (RWA) process in Wavelength Switched Optical Networks (WSONs). The purpose of the information described in this model is to facilitate constrained optical path computation in WSONs. This model takes into account compatibility constraints between WSON signal attributes and network elements but does not include constraints due to optical impairments. Aspects of this information that may be of use to other technologies utilizing a GMPLS control plane are discussed.

This memo provides application-specific requirements for the Path Computation Element Communication Protocol (PCEP) for the support of Wavelength Switched Optical Networks (WSONs). Lightpath provisioning in WSONs requires a Routing and Wavelength Assignment (RWA) process. From a path computation perspective, wavelength assignment is the process of determining which wavelength can be used on each hop of a path and forms an additional routing constraint to optical light path computation. Requirements for PCEP extensions in support of optical impairments will be addressed in a separate document.

The work related to GMPLS Ethernet Label Switching (GELS) extended GMPLS RSVP-TE to support the establishment of Ethernet Label Switching Paths (LSPs). IEEE Ethernet Connectivity Fault Management (CFM) specifies an adjunct Operations, Administration, and Maintenance (OAM) flow to check connectivity in Ethernet networks. CFM can also be used with Ethernet LSPs for fault detection and triggering recovery mechanisms. The ITU-T Y.1731 specification builds on CFM and specifies additional OAM mechanisms, including Performance Monitoring, for Ethernet networks. This document specifies extensions of the GMPLS RSVP-TE protocol to support the setup of the associated Ethernet OAM entities of Ethernet LSPs and defines the Ethernet technology-specific TLVs based on the GMPLS OAM Configuration Framework. This document supports, but does not modify, the IEEE and ITU-T OAM mechanisms.

Operations, Administration, and Maintenance (OAM) is an integral part of transport connections; hence, it is required that OAM functions be activated/deactivated in sync with connection commissioning/ decommissioning, in order to avoid spurious alarms and ensure consistent operation. In certain technologies, OAM entities are inherently established once the connection is set up, while other technologies require extra configuration to establish and configure OAM entities. This document specifies extensions to Resource Reservation Protocol - Traffic Engineering (RSVP-TE) to support the establishment and configuration of OAM entities along with Label Switched Path signaling.

This document describes alternate mechanisms to perform some of the functions of MPLS Transport Profile (MPLS-TP) linear protection defined in RFC 6378, and also defines additional mechanisms. The purpose of these alternate and additional mechanisms is to provide operator control and experience that more closely models the behavior of linear protection seen in other transport networks.

This document also introduces capabilities and modes for linear protection. A capability is an individual behavior, and a mode is a particular combination of capabilities. Two modes are defined in this document: Protection State Coordination (PSC) mode and Automatic Protection Switching (APS) mode.

This document describes the behavior of the PSC protocol including priority logic and state machine when all the capabilities associated with the APS mode are enabled.

This document updates RFC 6378 in that the capability advertisement method defined here is an addition to that document.

This document describes Open Shortest Path First - Traffic Engineering (OSPF-TE) routing protocol extensions to support GMPLS control of Optical Transport Networks (OTNs) specified in ITU-T Recommendation G.709 as published in 2012. It extends mechanisms defined in RFC 4203.

ITU-T Recommendation G.709 [G709-2012] introduced new Optical channel Data Unit (ODU) containers (ODU0, ODU4, ODU2e, and ODUflex) and enhanced Optical Transport Network (OTN) flexibility.

This document updates the ODU-related portions of RFC 4328 to provide extensions to GMPLS signaling to control the full set of OTN features, including ODU0, ODU4, ODU2e, and ODUflex.

ITU-T recommendation G.709-2012 has introduced new fixed and flexible Optical channel Data Unit (ODU) containers in Optical Transport Networks (OTNs).

This document provides an evaluation of existing Generalized Multiprotocol Label Switching (GMPLS) routing and signaling protocols against the G.709 OTNs.

This document provides a framework to allow the development of protocol extensions to support Generalized Multi-Protocol Label Switching (GMPLS) and Path Computation Element (PCE) control of Optical Transport Networks (OTNs) as specified in ITU-T Recommendation G.709 as published in 2012.

GMPLS provides control for multiple switching technologies and for hierarchical switching within a technology. GMPLS routing and signaling use common values to indicate the type of switching technology. These values are carried in routing protocols via the Switching Capability field, and in signaling protocols via the Switching Type field. While the values used in these fields are the primary indicators of the technology and hierarchy level being controlled, the values are not consistently defined and used across the different technologies supported by GMPLS. This document is intended to resolve the inconsistent definition and use of the Switching Capability and Type fields by narrowly scoping the meaning and use of the fields. This document updates all documents that use the GMPLS Switching Capability and Types fields, in particular RFCs 3471, 4202, 4203, and 5307.

The initial effort of the PCE (Path Computation Element) WG focused mainly on MPLS. As a next step, this document describes functional requirements for GMPLS applications of PCE.

The purpose of this document is to provide applicability of the Access Node Control Mechanism to broadband access based on Passive Optical Networks (PONs). The need for an Access Node Control Mechanism between a Network Access Server (NAS) and an Access Node Complex, composed of a combination of Optical Line Termination (OLT) and Optical Network Termination (ONT) elements, is described in a multi-service reference architecture in order to perform QoS-related, service-related, and subscriber-related operations. The Access Node Control Mechanism is also extended for interaction between components of the Access Node Complex (OLT and ONT). The Access Node Control Mechanism will ensure that the transmission of information between the NAS and Access Node Complex (ANX) and between the OLT and ONT within an ANX does not need to go through distinct element managers but rather uses direct device-to-device communication and stays on net. This allows for performing access-link-related operations within those network elements to meet performance objectives.

The Link Management Protocol (LMP) is used to coordinate the properties, use, and faults of data links in networks controlled by Generalized Multiprotocol Label Switching (GMPLS). This document defines an extension to LMP to negotiate capabilities and indicate support for LMP extensions. The defined extension is compatible with non-supporting implementations.

This document updates RFC 4204, RFC 4207, RFC 4209, and RFC 5818.

This memo defines the Management Information Base (MIB) objects for managing the Traffic Engineering Database (TED) information with extensions in support of the Multiprotocol Label Switching (MPLS) with Traffic Engineering (TE) as well as Generalized MPLS (GMPLS) for use with network management protocols. [STANDARDS-TRACK]

The ITU-T has defined an architecture and requirements for operating an Automatically Switched Optical Network (ASON).

The Generalized Multiprotocol Label Switching (GMPLS) protocol suite is designed to provide a control plane for a range of network technologies. These include optical networks such as time division multiplexing (TDM) networks including the Synchronous Optical Network/Synchronous Digital Hierarchy (SONET/SDH), Optical Transport Networks (OTNs), and lambda switching optical networks.

The requirements for GMPLS routing to satisfy the requirements of ASON routing and an evaluation of existing GMPLS routing protocols are provided in other documents. This document defines extensions to the OSPFv2 Link State Routing Protocol to meet the requirements for routing in an ASON.

Note that this work is scoped to the requirements and evaluation expressed in RFC 4258 and RFC 4652 and the ITU-T Recommendations that were current when those documents were written. Future extensions or revisions of this work may be necessary if the ITU-T Recommendations are revised or if new requirements are introduced into a revision of RFC 4258. This document obsoletes RFC 5787 and updates RFC 5786. [STANDARDS-TRACK]

Computing optimum routes for Label Switched Paths (LSPs) across multiple domains in MPLS Traffic Engineering (MPLS-TE) and GMPLS networks presents a problem because no single point of path computation is aware of all of the links and resources in each domain. A solution may be achieved using the Path Computation Element (PCE) architecture.

Where the sequence of domains is known a priori, various techniques can be employed to derive an optimum path. If the domains are simply connected, or if the preferred points of interconnection are also known, the Per-Domain Path Computation technique can be used. Where there are multiple connections between domains and there is no preference for the choice of points of interconnection, the Backward-Recursive PCE-based Computation (BRPC) procedure can be used to derive an optimal path.

This document examines techniques to establish the optimum path when the sequence of domains is not known in advance. The document shows how the PCE architecture can be extended to allow the optimum sequence of domains to be selected, and the optimum end-to-end path to be derived through the use of a hierarchical relationship between domains. This document is not an Internet Standards Track specification; it is published for informational purposes.

When setting up a Label Switched Path (LSP) in Generalized MPLS (GMPLS) and MPLS Traffic Engineering (MPLS-TE) networks, the completion of the signaling process does not necessarily mean that the cross-connection along the LSP has been programmed accordingly and in a timely manner. Meanwhile, the completion of the signaling process may be used by LSP users or applications that control their use as an indication that the data path has become usable. The existence of the inconsistency between the signaling messages and cross-connection programming, and the possible failure of cross- connection programming, if not properly treated, will result in data loss or even application failure. Characterization of this performance can thus help designers to improve the way in which LSPs are used and to make applications or tools that depend on and use LSPs more robust. This document defines a series of performance metrics to evaluate the connectivity of the data path in the signaling process. [STANDARDS-TRACK]

The RSVP ASSOCIATION object was defined in the context of GMPLS-controlled Label Switched Paths (LSPs). In this context, the object is used to associate recovery LSPs with the LSP they are protecting. This object also has broader applicability as a mechanism to associate RSVP state. This document defines how the ASSOCIATION object can be more generally applied. This document also defines Extended ASSOCIATION objects that, in particular, can be used in the context of the MPLS Transport Profile (MPLS-TP). This document updates RFC 2205, RFC 3209, and RFC 3473. It also generalizes the definition of the Association ID field defined in RFC 4872. [STANDARDS-TRACK]

The Resource Reservation Protocol (RSVP) ASSOCIATION object is defined in the context of GMPLS-controlled label switched paths (LSPs). In this context, the object is used to associate recovery LSPs with the LSP they are protecting. This document reviews how the association is to be provided in the context of GMPLS recovery. No new procedures or mechanisms are defined by this document, and it is strictly informative in nature. This document is not an Internet Standards Track specification; it is published for informational purposes.

As an optical signal progresses along its path, it may be altered by the various physical processes in the optical fibers and devices it encounters. When such alterations result in signal degradation, these processes are usually referred to as "impairments". These physical characteristics may be important constraints to consider when using a GMPLS control plane to support path setup and maintenance in wavelength switched optical networks.

This document provides a framework for applying GMPLS protocols and the Path Computation Element (PCE) architecture to support Impairment-Aware Routing and Wavelength Assignment (IA-RWA) in wavelength switched optical networks. Specifically, this document discusses key computing constraints, scenarios, and architectural processes: routing, wavelength assignment, and impairment validation. This document does not define optical data plane aspects; impairment parameters; or measurement of, or assessment and qualification of, a route; rather, it describes the architectural and information components for protocol solutions. This document is not an Internet Standards Track specification; it is published for informational purposes.

Multiprotocol Label Switching (MPLS) Label Switched Paths (LSPs) established using the Resource Reservation Protocol Traffic Engineering (RSVP-TE) extensions may be signaled with a set of LSP-specific attributes. These attributes may be carried in both Path and Resv messages. This document specifies how LSP attributes are to be carried in RSVP Path and Resv messages using the Routing Backus-Naur Form and clarifies related Resv message formats. This document updates RFC 4875 and RFC 5420. [STANDARDS-TRACK]

The Path Computation Element (PCE) provides functions of path computation in support of traffic engineering in networks controlled by Multi-Protocol Label Switching (MPLS) and Generalized MPLS (GMPLS).

MPLS and GMPLS networks may be constructed from layered client/server networks. It is advantageous for overall network efficiency to provide end-to-end traffic engineering across multiple network layers. PCE is a candidate solution for such requirements.

Generic requirements for a communication protocol between Path Computation Clients (PCCs) and PCEs are presented in RFC 4657, "Path Computation Element (PCE) Communication Protocol Generic Requirements". Generic requirements for a PCE discovery protocol are presented in RFC 4674, "Requirements for Path Computation Element (PCE) Discovery".

This document complements the generic requirements and presents detailed sets of PCC-PCE communication protocol requirements and PCE discovery protocol requirements for inter-layer traffic engineering. This document is not an Internet Standards Track specification; it is published for informational purposes.

This document describes the application of MPLS multi-segment pseudowires (MS-PWs) in a dual-technology environment comprising a Passive Optical Network (PON) and an MPLS Packet Switched Network (PSN).

PON technology may be used in mobile backhaul networks to support the end segments closest to the aggregation devices. In these cases, there may be a very large number of pseudowire (PW) Terminating Provider Edge (T-PE) nodes. The MPLS control plane could be used to provision these end segments, but support for the necessary protocols would complicate the management of the T-PEs and would significantly increase their expense. Alternatively, static, or management plane, configuration could be used to configure the end segments, but the very large number of such segments in a PON places a very heavy burden on the network manager.

This document describes how to set up the end segment of an end-to- end MPLS PW over a Gigabit-capable Passive Optical Network (G-PON) or 10 Gigabit-capable Passive Optical Network (XG-PON) using the G-PON and XG-PON management protocol, Optical Network Termination Management and Control Interface (OMCI). This simplifies and speeds up PW provisioning compared with manual configuration.

This document also shows how an MS-PW may be constructed from an end segment supported over a PON, and switched to one or more segments supported over an MPLS PSN. This document is not an Internet Standards Track specification; it is published for informational purposes.

The Resource Reservation Protocol (RSVP) has been extended to support Traffic Engineering (TE) in Multiprotocol Label Switching (MPLS) and Generalized MPLS (GMPLS) networks. The protocol enables signaling exchanges to establish Label Switched Paths (LSPs) that traverse nodes and link to provide end-to-end data paths. Each node is programmed with "cross-connect" information as the signaling messages are processed. The cross-connection information instructs the node how to forward data that it receives.

End points of an LSP need to know when it is safe to start sending data so that it is not misdelivered, and so that safety issues specific to optical data-plane technology are satisfied. Likewise, all label switching routers along the path of the LSP need to know when to program their data planes relative to sending and receiving control-plane messages.

This document clarifies and summarizes the RSVP-TE protocol exchanges with relation to the programming of cross-connects along an LSP for both unidirectional and bidirectional LSPs. This document does not define any new procedures or protocol extensions, and defers completely to the documents that provide normative references. The clarifications set out in this document may also be used to help interpret LSP establishment performance figures for MPLS-TE and GMPLS devices. This document is not an Internet Standards Track specification; it is published for informational purposes.

This document defines a method for the support of GMPLS asymmetric bandwidth bidirectional Label Switched Paths (LSPs). The approach presented is applicable to any switching technology and builds on the original Resource Reservation Protocol (RSVP) model for the transport of traffic-related parameters. This document moves the experiment documented in RFC 5467 to the standards track and obsoletes RFC 5467. [STANDARDS-TRACK]

The MPLS Transport Profile (MPLS-TP) supports static provisioning of transport paths via a Network Management System (NMS) and dynamic provisioning of transport paths via a control plane. This document provides the framework for MPLS-TP dynamic provisioning and covers control-plane addressing, routing, path computation, signaling, traffic engineering, and path recovery. MPLS-TP uses GMPLS as the control plane for MPLS-TP Label Switched Paths (LSPs). MPLS-TP also uses the pseudowire (PW) control plane for pseudowires. Management-plane functions are out of scope of this document.

This document is a product of a joint Internet Engineering Task Force (IETF) / International Telecommunication Union Telecommunication Standardization Sector (ITU-T) effort to include an MPLS Transport Profile within the IETF MPLS and Pseudowire Emulation Edge-to-Edge (PWE3) architectures to support the capabilities and functionalities of a packet transport network as defined by the ITU-T.

This document is not an Internet Standards Track specification; it is published for informational purposes.

This document describes requirements for, and the use of, the Generalized Multi-Protocol Label Switching (GMPLS) control plane in support of the Virtual Concatenation (VCAT) layer 1 inverse multiplexing data plane mechanism and its companion Link Capacity Adjustment Scheme (LCAS). LCAS can be used for hitless dynamic resizing of the inverse multiplex group. These techniques apply to Optical Transport Network (OTN), Synchronous Optical Network (SONET), Synchronous Digital Hierarchy (SDH), and Plesiochronous Digital Hierarchy (PDH) signals. This document updates RFC 4606 by making modifications to the procedures for supporting virtual concatenation. [STANDARDS-TRACK]

This memo defines a portion of the Management Information Base (MIB) for use with network management protocols in the Internet community. In particular, it describes managed objects for modeling Synchronous Optical Network/Synchronous Digital Hierarchy (SONET/SDH) circuits over a Packet Switch Network (PSN). [STANDARDS-TRACK]

This document provides a framework for applying Generalized Multi-Protocol Label Switching (GMPLS) and the Path Computation Element (PCE) architecture to the control of Wavelength Switched Optical Networks (WSONs). In particular, it examines Routing and Wavelength Assignment (RWA) of optical paths.

This document focuses on topological elements and path selection constraints that are common across different WSON environments; as such, it does not address optical impairments in any depth. This document is not an Internet Standards Track specification; it is published for informational purposes.

Technology in the optical domain is constantly evolving, and, as a consequence, new equipment providing lambda switching capability has been developed and is currently being deployed.

Generalized MPLS (GMPLS) is a family of protocols that can be used to operate networks built from a range of technologies including wavelength (or lambda) switching. For this purpose, GMPLS defined a wavelength label as only having significance between two neighbors. Global wavelength semantics are not considered.

In order to facilitate interoperability in a network composed of next generation lambda-switch-capable equipment, this document defines a standard lambda label format that is compliant with the Dense Wavelength Division Multiplexing (DWDM) and Coarse Wavelength Division Multiplexing (CWDM) grids defined by the International Telecommunication Union Telecommunication Standardization Sector. The label format defined in this document can be used in GMPLS signaling and routing protocols. [STANDARDS-TRACK]

This specification is complementary to the GMPLS Ethernet Label Switching Architecture and Framework and describes the technology-specific aspects of GMPLS control for Provider Backbone Bridge Traffic Engineering (PBB-TE). The necessary GMPLS extensions and mechanisms are described to establish Ethernet PBB-TE point-to-point (P2P) and point-to-multipoint (P2MP) connections. This document supports, but does not modify, the standard IEEE data plane. [STANDARDS-TRACK]

Label Switched Paths (LSPs) set up in Multiprotocol Label Switching (MPLS) or Generalized MPLS (GMPLS) networks can be used to form links to carry traffic in those networks or in other (client) networks.

Protocol mechanisms already exist to facilitate the establishment of such LSPs and to bundle traffic engineering (TE) links to reduce the load on routing protocols. This document defines extensions to those mechanisms to support identifying the use to which such LSPs are to be put and to enable the TE link endpoints to be assigned addresses or unnumbered identifiers during the signaling process. [STANDARDS-TRACK]

There are specific requirements for the support of networks comprising Label Switching Routers (LSRs) participating in different data plane switching layers controlled by a single Generalized Multi-Protocol Label Switching (GMPLS) control plane instance, referred to as GMPLS Multi-Layer Networks / Multi-Region Networks (MLN/MRN).

This document defines extensions to GMPLS routing and signaling protocols so as to support the operation of GMPLS Multi-Layer / Multi-Region Networks. It covers the elements of a single GMPLS control plane instance controlling multiple Label Switched Path (LSP) regions or layers within a single Traffic Engineering (TE) domain. [STANDARDS-TRACK]

This document describes two technology-independent extensions to Generalized Multi-Protocol Label Switching (GMPLS). The first extension defines the new switching type Data Channel Switching Capable. Data Channel Switching Capable interfaces are able to support switching of the whole digital channel presented on single channel interfaces. The second extension defines a new type of generalized label and updates related objects. The new label is called the Generalized Channel_Set Label and allows more than one data plane label to be controlled as part of a Label Switched Path (LSP). [STANDARDS-TRACK]

This document describes the support of Metro Ethernet Forum (MEF) Ethernet traffic parameters as described in MEF10.1 when using Generalized Multi-Protocol Label Switching (GMPLS) Resource ReSerVation Protocol - Traffic Engineering (RSVP-TE) signaling. [STANDARDS-TRACK]

This document describes a method for controlling two specific types of Ethernet switching via Generalized Multi-Protocol Label Switching (GMPLS). This document supports the types of switching corresponding to the Ethernet services that have been defined in the context of the Metro Ethernet Forum (MEF) and International Telecommunication Union (ITU) G.8011. Specifically, switching in support of Ethernet private line and Ethernet virtual private line services are covered. Support for MEF- and ITU-defined parameters is also covered.

This document describes a method for controlling two specific types of Ethernet switching via a GMPLS-based User Network Interface (UNI). This document supports the types of switching required by the Ethernet services that have been defined in the context of the Metro Ethernet Forum (MEF) and International Telecommunication Union (ITU) G.8011. This document is the UNI companion to "Generalized MPLS (GMPLS) Support for Metro Ethernet Forum and G.8011 Ethernet Service Switching". This document does not define or limit the underlying intra-domain or Internal NNI (I-NNI) technology used to support the UNI. [STANDARDS- TRACK]

This document provides a security framework for Multiprotocol Label Switching (MPLS) and Generalized Multiprotocol Label Switching (GMPLS) Networks. This document addresses the security aspects that are relevant in the context of MPLS and GMPLS. It describes the security threats, the related defensive techniques, and the mechanisms for detection and reporting. This document emphasizes RSVP-TE and LDP security considerations, as well as inter-AS and inter-provider security considerations for building and maintaining MPLS and GMPLS networks across different domains or different Service Providers. This document is not an Internet Standards Track specification; it is published for informational purposes.

The Path Computation Element (PCE) provides path computation functions in support of traffic engineering in Multiprotocol Label Switching (MPLS) and Generalized MPLS (GMPLS) networks.

Extensions to the MPLS and GMPLS signaling and routing protocols have been made in support of point-to-multipoint (P2MP) Traffic Engineered (TE) Label Switched Paths (LSPs). The use of PCE in MPLS networks is already established, and since P2MP TE LSP routes are sometimes complex to compute, it is likely that PCE will be used for P2MP LSPs.

Generic requirements for a communication protocol between Path Computation Clients (PCCs) and PCEs are presented in RFC 4657, "Path Computation Element (PCE) Communication Protocol Generic Requirements". This document complements the generic requirements and presents a detailed set of PCC-PCE communication protocol requirements for point-to-multipoint MPLS/GMPLS traffic engineering. This document is not an Internet Standards Track specification; it is published for informational purposes.

MPLS-TE Graceful Shutdown is a method for explicitly notifying the nodes in a Traffic Engineering (TE) enabled network that the TE capability on a link or on an entire Label Switching Router (LSR) is going to be disabled. MPLS-TE graceful shutdown mechanisms are tailored toward addressing planned outage in the network.

This document provides requirements and protocol mechanisms to reduce or eliminate traffic disruption in the event of a planned shutdown of a network resource. These operations are equally applicable to both MPLS-TE and its Generalized MPLS (GMPLS) extensions. This document is not an Internet Standards Track specification; it is published for informational purposes.

This document defines simple additions to the Link Management Protocol (LMP) to provide a control plane tool that can assist in the location of stranded resources by allowing adjacent Label-Switching Routers (LSRs) to confirm data channel statuses and provide triggers for notifying the management plane if any discrepancies are found. As LMP is already used to verify data plane connectivity, it is considered to be an appropriate candidate to support this feature. [STANDARDS-TRACK]

In a transport network scenario, Data Plane connections controlled by either a Generalized Multiprotocol Label Switching (GMPLS) Control Plane (Soft Permanent Connections - SPC) or a Management System (Permanent Connections - PC) may independently coexist. The ability of transforming an existing PC into an SPC and vice versa -- without actually affecting Data Plane traffic being carried over it -- is a requirement. The requirements for the conversion between permanent connections and switched connections in a GMPLS Network are defined in RFC 5493.

This memo describes an extension to GMPLS Resource Reservation Protocol - Traffic Engineering (RSVP-TE) signaling that enables the transfer of connection ownership between the Management and the Control Planes. Such a transfer is referred to as a Handover. This document defines all Handover-related procedures. This includes the handling of failure conditions and subsequent reversion to original state. A basic premise of the extension is that the Handover procedures must never impact an already established Data Plane connection. [STANDARDS-TRACK]

There has been significant recent work in increasing the capabilities of Ethernet switches and Ethernet forwarding models. As a consequence, the role of Ethernet is rapidly expanding into "transport networks" that previously were the domain of other technologies such as Synchronous Optical Network (SONET) / Synchronous Digital Hierarchy (SDH), Time-Division Multiplexing (TDM), and Asynchronous Transfer Mode (ATM). This document defines an architecture and framework for a Generalized- MPLS-based control plane for Ethernet in this "transport network" capacity. GMPLS has already been specified for similar technologies. Some additional extensions to the GMPLS control plane are needed, and this document provides a framework for these extensions. This document is not an Internet Standards Track specification; it is published for informational purposes.

Generalized Multi-Protocol Label Switching (GMPLS) is one of the most promising candidate technologies for a future data transmission network. GMPLS has been developed to control and operate different kinds of network elements, such as conventional routers, switches, Dense Wavelength Division Multiplexing (DWDM) systems, Add-Drop Multiplexers (ADMs), photonic cross-connects (PXCs), optical cross- connects (OXCs), etc. These physically diverse devices differ drastically from one another in dynamic provisioning ability. At the same time, the need for dynamically provisioned connections is increasing because optical networks are being deployed in metro areas. As different applications have varied requirements in the provisioning performance of optical networks, it is imperative to define standardized metrics and procedures such that the performance of networks and application needs can be mapped to each other.

This document provides a series of performance metrics to evaluate the dynamic Label Switched Path (LSP) provisioning performance in GMPLS networks, specifically the dynamic LSP setup/release performance. These metrics can be used to characterize the features of GMPLS networks in LSP dynamic provisioning. [STANDARDS-TRACK]

This document describes how Resource ReserVation Protocol (RSVP) PathErr messages may be used to trigger rerouting of Multi-Protocol Label Switching (MPLS) and Generalized MPLS (GMPLS) point-to-point Traffic Engineering (TE) Label Switched Paths (LSPs) without first removing LSP state or resources. Such LSP rerouting may be desirable in a number of cases, including, for example, soft-preemption and graceful shutdown. This document describes the usage of existing Standards Track mechanisms to support LSP rerouting. In this case, it relies on mechanisms already defined as part of RSVP-TE and simply describes a sequence of actions to be executed. While existing protocol definitions can be used to support reroute applications, this document also defines a new reroute-specific error code to allow for the future definition of reroute-application-specific error values. [STANDARDS-TRACK]

The Path Computation Element (PCE) provides path computation functions in support of traffic engineering in Multiprotocol Label Switching (MPLS) and Generalized MPLS (GMPLS) networks.

Extensions to the MPLS and GMPLS signaling and routing protocols have been made in support of point-to-multipoint (P2MP) Traffic Engineered (TE) Label Switched Paths (LSPs).

This document examines the applicability of PCE to path computation for P2MP TE LSPs in MPLS and GMPLS networks. It describes the motivation for using a PCE to compute these paths and examines which of the PCE architectural models are appropriate. This memo provides information for the Internet community.

A network may comprise multiple layers. It is important to globally optimize network resource utilization, taking into account all layers rather than optimizing resource utilization at each layer independently. This allows better network efficiency to be achieved through a process that we call inter-layer traffic engineering. The Path Computation Element (PCE) can be a powerful tool to achieve inter-layer traffic engineering.

This document describes a framework for applying the PCE-based architecture to inter-layer Multiprotocol Label Switching (MPLS) and Generalized MPLS (GMPLS) traffic engineering. It provides suggestions for the deployment of PCE in support of multi-layer networks. This document also describes network models where PCE performs inter-layer traffic engineering, and the relationship between PCE and a functional component called the Virtual Network Topology Manager (VNTM). This memo provides information for the Internet community.

The paths taken by Multiprotocol Label Switching (MPLS) and Generalized MPLS (GMPLS) Traffic Engineering (TE) Label Switched Paths (LSPs) may be computed by Path Computation Elements (PCEs). Where the TE LSP crosses multiple domains, such as Autonomous Systems (ASes), the path may be computed by multiple PCEs that cooperate, with each responsible for computing a segment of the path.

To preserve confidentiality of topology within each AS, the PCEs support a mechanism to hide the contents of a segment of a path (such as the segment of the path that traverses an AS), called the Confidential Path Segment (CPS), by encoding the contents as a Path Key Subobject (PKS) and embedding this subobject within the result of its path computation.

This document describes how to carry Path Key Subobjects in the Resource Reservation Protocol (RSVP) Explicit Route Objects (EROs) and Record Route Objects (RROs) so as to facilitate confidentiality in the signaling of inter-domain TE LSPs. [STANDARDS-TRACK]

The Path Computation Element (PCE) provides functions of path computation in support of traffic engineering (TE) in Multi-Protocol Label Switching (MPLS) and Generalized MPLS (GMPLS) networks.

When a Path Computation Client (PCC) requests a PCE for a route, it may be useful for the PCC to specify, as constraints to the path computation, abstract nodes, resources, and Shared Risk Link Groups (SRLGs) that are to be explicitly excluded from the computed route. Such constraints are termed "route exclusions".

The PCE Communication Protocol (PCEP) is designed as a communication protocol between PCCs and PCEs. This document presents PCEP extensions for route exclusions. [STANDARDS-TRACK]

From a carrier perspective, the possibility of turning a permanent connection (PC) into a soft permanent connection (SPC) and vice versa, without actually affecting data plane traffic being carried over it, is a valuable option. In other terms, such operation can be seen as a way of transferring the ownership and control of an existing and in-use data plane connection between the management plane and the control plane, leaving its data plane state untouched.

This memo sets out the requirements for such procedures within a Generalized Multiprotocol Label Switching (GMPLS) network. This memo provides information for the Internet community.

The Hello message for the Resource Reservation Protocol (RSVP) has been defined to establish and maintain basic signaling node adjacencies for Label Switching Routers (LSRs) participating in a Multiprotocol Label Switching (MPLS) traffic-engineered (TE) network. The Hello message has been extended for use in Generalized MPLS (GMPLS) networks for state recovery of control channel or nodal faults.

The GMPLS protocol definitions for RSVP also allow a restarting node to learn which label it previously allocated for use on a Label Switched Path (LSP).

Further RSVP protocol extensions have been defined to enable a restarting node to recover full control plane state by exchanging RSVP messages with its upstream and downstream neighbors.

This document provides an informational clarification of the control plane procedures for a GMPLS network when there are multiple node failures, and describes how full control plane state can be recovered in different scenarios where the order in which the nodes restart is different.

This document does not define any new processes or procedures. All protocol mechanisms are already defined in the referenced documents. This memo provides information for the Internet community.

This document specifies the Path Computation Element (PCE) Communication Protocol (PCEP) for communications between a Path Computation Client (PCC) and a PCE, or between two PCEs. Such interactions include path computation requests and path computation replies as well as notifications of specific states related to the use of a PCE in the context of Multiprotocol Label Switching (MPLS) and Generalized MPLS (GMPLS) Traffic Engineering. PCEP is designed to be flexible and extensible so as to easily allow for the addition of further messages and objects, should further requirements be expressed in the future. [STANDARDS-TRACK]

This RFC archives the report of the IETF - ITU-T Joint Working Team (JWT) on the application of MPLS to transport networks. The JWT recommended of Option 1: The IETF and the ITU-T jointly agree to work together and bring transport requirements into the IETF and extend IETF MPLS forwarding, OAM (Operations, Administration, and Management), survivability, network management and control plane protocols to meet those requirements through the IETF Standards Process. This RFC is available in ASCII (which contains a summary of the slides) and in PDF (which contains the summary and a copy of the slides). This memo provides information for the Internet community.

Multiprotocol Label Switching (MPLS) Label Switched Paths (LSPs) may be established using the Resource Reservation Protocol Traffic Engineering (RSVP-TE) extensions. This protocol includes an object (the SESSION_ATTRIBUTE object) that carries a Flags field used to indicate options and attributes of the LSP. That Flags field has eight bits, allowing for eight options to be set. Recent proposals in many documents that extend RSVP-TE have suggested uses for each of the previously unused bits.

This document defines a new object for RSVP-TE messages that allows the signaling of further attribute bits and also the carriage of arbitrary attribute parameters to make RSVP-TE easily extensible to support new requirements. Additionally, this document defines a way to record the attributes applied to the LSP on a hop-by-hop basis.

The object mechanisms defined in this document are equally applicable to Generalized MPLS (GMPLS) Packet Switch Capable (PSC) LSPs and to GMPLS non-PSC LSPs.

This document replaces and obsoletes the previous version of this work, published as RFC 4420. The only change is in the encoding of the Type-Length-Variable (TLV) data structures. [STANDARDS-TRACK]

This document describes extensions to the OSPF version 2 and 3 protocols to support Multiprotocol Label Switching (MPLS) and Generalized MPLS (GMPLS) Traffic Engineering (TE) for multiple Autonomous Systems (ASes). OSPF-TE v2 and v3 extensions are defined for the flooding of TE information about inter-AS links that can be used to perform inter-AS TE path computation.

No support for flooding information from within one AS to another AS is proposed or defined in this document. [STANDARDS-TRACK]

Multiprotocol Label Switching Traffic Engineered (MPLS TE) Label Switched Paths (LSPs) may be established wholly within an Autonomous System (AS) or may cross AS boundaries.

The Path Computation Element (PCE) is a component that is capable of computing constrained paths for (G)MPLS TE LSPs. The PCE Communication Protocol (PCECP) is defined to allow communication between Path Computation Clients (PCCs) and PCEs, as well as between PCEs. The PCECP is used to request constrained paths and to supply computed paths in response. Generic requirements for the PCECP are set out in "Path Computation Element (PCE) Communication Protocol Generic Requirements", RFC 4657. This document extends those requirements to cover the use of PCECP in support of inter-AS MPLS TE. This memo provides information for the Internet community.

This document specifies encoding of extensions to the IS-IS routing protocol in support of Generalized Multi-Protocol Label Switching (GMPLS). [STANDARDS-TRACK]

This document provides an evaluation of Generalized Multiprotocol Label Switching (GMPLS) protocols and mechanisms against the requirements for Multi-Layer Networks (MLNs) and Multi-Region Networks (MRNs). In addition, this document identifies areas where additional protocol extensions or procedures are needed to satisfy these requirements, and provides guidelines for potential extensions. This memo provides information for the Internet community.

Protection and recovery are important features of service offerings in Multiprotocol Label Switching (MPLS) and Generalized MPLS (GMPLS) networks. Increasingly, MPLS and GMPLS networks are being extended from single domain scope to multi-domain environments.

Various schemes and processes have been developed to establish Label Switched Paths (LSPs) in multi-domain environments. These are discussed in RFC 4726: "A Framework for Inter-Domain Multiprotocol Label Switching Traffic Engineering".

This document analyzes the application of these techniques to protection and recovery in multi-domain networks. The main focus for this document is on establishing end-to-end diverse Traffic Engineering (TE) LSPs in multi-domain networks. This memo provides information for the Internet community.

Most of the initial efforts to utilize Generalized MPLS (GMPLS) have been related to environments hosting devices with a single switching capability. The complexity raised by the control of such data planes is similar to that seen in classical IP/MPLS networks. By extending MPLS to support multiple switching technologies, GMPLS provides a comprehensive framework for the control of a multi-layered network of either a single switching technology or multiple switching technologies.

In GMPLS, a switching technology domain defines a region, and a network of multiple switching types is referred to in this document as a multi-region network (MRN). When referring in general to a layered network, which may consist of either single or multiple regions, this document uses the term multi-layer network (MLN). This document defines a framework for GMPLS based multi-region / multi-layer networks and lists a set of functional requirements. This memo provides information for the Internet community.

This document provides an applicability statement on the use of Generalized Multiprotocol Label Switching (GMPLS) protocols and mechanisms to support Basic Mode Layer 1 Virtual Private Networks (L1VPNs).

L1VPNs provide customer services and connectivity at Layer 1 over Layer 1 networks. The operation of L1VPNs is divided into the Basic Mode and the Enhanced Mode, where the Basic Mode of operation does not feature any exchange of routing information between the Layer 1 network and the customer domain. This document examines how GMPLS protocols can be used to satisfy the requirements of a Basic Mode L1VPN. This memo provides information for the Internet community.

The migration from Multiprotocol Label Switching (MPLS) Traffic Engineering (TE) to Generalized MPLS (GMPLS) is the process of evolving an MPLS-TE control plane to a GMPLS control plane. An appropriate migration strategy will be selected based on various factors including the service provider's network deployment plan, customer demand, and operational policy.

This document presents several migration models and strategies for migrating from MPLS-TE to GMPLS. In the course of migration, MPLS-TE and GMPLS devices, or networks, may coexist that may require interworking between MPLS-TE and GMPLS protocols. Aspects of the required interworking are discussed as it will influence the choice of a migration strategy. This framework document provides a migration toolkit to aid the operator in selection of an appropriate strategy.

This framework document also lists a set of solutions that may aid in interworking, and highlights a set of potential issues. This memo provides information for the Internet community.

Operation of a Multiprotocol Label Switching (MPLS) traffic engineering (TE) network as a client network to a Generalized MPLS (GMPLS) network has enhanced operational capabilities compared to those provided by a coexistent protocol model (i.e., operation of MPLS-TE over an independently managed transport layer).

The GMPLS network may be a packet or a non-packet network, and may itself be a multi-layer network supporting both packet and non-packet technologies. An MPLS-TE Label Switched Path (LSP) originates and terminates on an MPLS Label Switching Router (LSR). The GMPLS network provides transparent transport for the end-to-end MPLS-TE LSP.

This document describes a framework and Service Provider requirements for operating MPLS-TE networks over GMPLS networks. This memo provides information for the Internet community.

In certain scenarios, there may be a need to combine several Generalized Multiprotocol Label Switching (GMPLS) Label Switched Paths (LSPs) such that a single end-to-end (e2e) LSP is realized and all traffic from one constituent LSP is switched onto the next LSP. We will refer to this as "LSP stitching", the key requirement being that a constituent LSP not be allocated to more than one e2e LSP. The constituent LSPs will be referred to as "LSP segments" (S-LSPs).

This document describes extensions to the existing GMPLS signaling protocol (Resource Reservation Protocol-Traffic Engineering (RSVP-TE)) to establish e2e LSPs created from S-LSPs, and describes how the LSPs can be managed using the GMPLS signaling and routing protocols.

It may be possible to configure a GMPLS node to switch the traffic from an LSP for which it is the egress, to another LSP for which it is the ingress, without requiring any signaling or routing extensions whatsoever and such that the operation is completely transparent to other nodes. This will also result in LSP stitching in the data plane. However, this document does not cover this scenario of LSP stitching. [STANDARDS-TRACK]

This document describes procedures and protocol extensions for the use of Resource Reservation Protocol-Traffic Engineering (RSVP-TE) signaling in Multiprotocol Label Switching-Traffic Engineering (MPLS-TE) packet networks and Generalized MPLS (GMPLS) packet and non-packet networks to support the establishment and maintenance of Label Switched Paths that cross domain boundaries.

For the purpose of this document, a domain is considered to be any collection of network elements within a common realm of address space or path computation responsibility. Examples of such domains include Autonomous Systems, Interior Gateway Protocol (IGP) routing areas, and GMPLS overlay networks. [STANDARDS-TRACK]

This document specifies a per-domain path computation technique for establishing inter-domain Traffic Engineering (TE) Multiprotocol Label Switching (MPLS) and Generalized MPLS (GMPLS) Label Switched Paths (LSPs). In this document, a domain refers to a collection of network elements within a common sphere of address management or path computational responsibility such as Interior Gateway Protocol (IGP) areas and Autonomous Systems.

Per-domain computation applies where the full path of an inter-domain TE LSP cannot be or is not determined at the ingress node of the TE LSP, and is not signaled across domain boundaries. This is most likely to arise owing to TE visibility limitations. The signaling message indicates the destination and nodes up to the next domain boundary. It may also indicate further domain boundaries or domain identifiers. The path through each domain, possibly including the choice of exit point from the domain, must be determined within the domain. [STANDARDS-TRACK]

It is highly desired, in several cases, to take into account Traffic Engineering (TE) node capabilities during Multi Protocol Label Switching (MPLS) and Generalized MPLS (GMPLS) Traffic Engineered Label Switched Path (TE-LSP) selection, such as, for instance, the capability to act as a branch Label Switching Router (LSR) of a Point-To-MultiPoint (P2MP) LSP. This requires advertising these capabilities within the Interior Gateway Protocol (IGP). For that purpose, this document specifies Open Shortest Path First (OSPF) and Intermediate System-Intermediate System (IS-IS) traffic engineering extensions for the advertisement of control plane and data plane traffic engineering node capabilities. [STANDARDS-TRACK]

This document describes extensions to the Resource Reservation Protocol (RSVP) Graceful Restart mechanisms defined in RFC 3473. The extensions enable the recovery of RSVP signaling state based on the Path message last sent by the node being restarted.

Previously defined Graceful Restart mechanisms, also called recovery from nodal faults, permit recovery of signaling state from adjacent nodes when the data plane has retained the associated forwarding state across a restart. Those mechanisms do not fully support signaling state recovery on ingress nodes or recovery of all RSVP objects.

The extensions defined in this document build on the RSVP Hello extensions defined in RFC 3209, and extensions for state recovery on nodal faults defined in RFC 3473. Using these extensions, the restarting node can recover all previously transmitted Path state, including the Explicit Route Object and the downstream (outgoing) interface identifiers. The extensions can also be used to recover signaling state after the restart of an ingress node.

These extensions are not used to create or restore data plane state.

The extensions optionally support the use of Summary Refresh, defined in RFC 2961, to reduce the number of messages exchanged during the Recovery Phase when the restarting node has recovered signaling state locally for one or more Label Switched Paths (LSPs). [STANDARDS-TRACK]

This document clarifies the use of addresses in Generalized Multiprotocol Label Switching (GMPLS) networks. The aim is to facilitate interworking of GMPLS-capable Label Switching Routers (LSRs). The document is based on experience gained in implementation, interoperability testing, and deployment.

The document describes how to interpret address and identifier fields within GMPLS protocols, and how to choose which addresses to set in those fields for specific control plane usage models. It also discusses how to handle IPv6 sources and destinations in the MPLS and GMPLS Traffic Engineering (TE) Management Information Base (MIB) modules.

This document does not define new procedures or processes. Whenever this document makes requirements statements or recommendations, these are taken from normative text in the referenced RFCs. This memo provides information for the Internet community.

In certain networking topologies, it may be advantageous to maintain associations between endpoints and key transit points to support an instance of a service. Such associations are known as Calls.

A Call does not provide the actual connectivity for transmitting user traffic, but only builds a relationship by which subsequent Connections may be made. In Generalized MPLS (GMPLS) such Connections are known as Label Switched Paths (LSPs).

This document specifies how GMPLS Resource Reservation Protocol - Traffic Engineering (RSVP-TE) signaling may be used and extended to support Calls. These mechanisms provide full and logical Call/Connection separation.

The mechanisms proposed in this document are applicable to any environment (including multi-area), and for any type of interface: packet, layer-2, time-division multiplexed, lambda, or fiber switching. [STANDARDS-TRACK]

The setup of a full mesh of Multi-Protocol Label Switching (MPLS) Traffic Engineering (TE) Label Switched Paths (LSP) among a set of Label Switch Routers (LSR) is a common deployment scenario of MPLS Traffic Engineering either for bandwidth optimization, bandwidth guarantees or fast rerouting with MPLS Fast Reroute. Such deployment may require the configuration of a potentially large number of TE LSPs (on the order of the square of the number of LSRs). This document specifies Interior Gateway Protocol (IGP) routing extensions for Intermediate System-to-Intermediate System (IS-IS) and Open Shortest Path First (OSPF) so as to provide an automatic discovery of the set of LSRs members of a mesh in order to automate the creation of such mesh of TE LSPs. [STANDARDS-TRACK]

In a distributed, constraint-based routing environment, the information used to compute a path may be out of date. This means that Multiprotocol Label Switching (MPLS) and Generalized MPLS (GMPLS) Traffic Engineered (TE) Label Switched Path (LSP) setup requests may be blocked by links or nodes without sufficient resources. Crankback is a scheme whereby setup failure information is returned from the point of failure to allow new setup attempts to be made avoiding the blocked resources. Crankback can also be applied to LSP recovery to indicate the location of the failed link or node.

This document specifies crankback signaling extensions for use in MPLS signaling using RSVP-TE as defined in "RSVP-TE: Extensions to RSVP for LSP Tunnels", RFC 3209, and GMPLS signaling as defined in "Generalized Multi-Protocol Label Switching (GMPLS) Signaling Functional Description", RFC 3473. These extensions mean that the LSP setup request can be retried on an alternate path that detours around blocked links or nodes. This offers significant improvements in the successful setup and recovery ratios for LSPs, especially in situations where a large number of setup requests are triggered at the same time. [STANDARDS-TRACK]

This document defines a portion of the Management Information Base (MIB) for use with network management protocols in TCP/IP based Internets. In particular, it defines objects for managing interfaces that conform to the Ethernet Passive Optical Networks (EPON) standard as defined in the IEEE Std 802.3ah-2004, which are extended capabilities to the Ethernet like interfaces. [STANDARDS-TRACK]

For scalability purposes, a network may comprise multiple Interior Gateway Protocol (IGP) areas. An inter-area Traffic Engineered Label Switched Path (TE-LSP) is an LSP that transits through at least two IGP areas. In a multi-area network, topology visibility remains local to a given area, and a head-end Label Switching Router (LSR) cannot compute an inter-area shortest constrained path. One key application of the Path Computation Element (PCE)-based architecture is the computation of inter-area TE-LSP paths. The PCE Communication Protocol (PCECP) is used to communicate computation requests from Path Computation Clients (PCCs) to PCEs, and to return computed paths in responses. This document lists a detailed set of PCECP-specific requirements for support of inter-area TE-LSP path computation. It complements the generic requirements for a PCE Communication Protocol. This memo provides information for the Internet community.

This document provides guidelines for applying or extending the MPLS or GMPLS ((G)MPLS) protocol suites and clarifies the IETF's (G)MPLS working groups' responsibility for the (G)MPLS protocols. This document is directed to multi-vendor fora and Standards Development Organizations (SDOs) to provide an understanding of (G)MPLS work in the IETF and documents the requisite use of IETF review procedures when considering (G)MPLS applications or protocol extensions in their work. This document does not modify IETF processes. This document specifies an Internet Best Current Practices for the Internet Community, and requests discussion and suggestions for improvements.

This document describes methods for transporting the Protocol Data Units (PDUs) of layer 2 protocols such as Frame Relay, Asynchronous Transfer Mode (ATM) Adaption Layer 5 (AAL5), and Ethernet, and for providing a Synchronized Optical Network (SONET) circuit emulation service across an MPLS network. This document describes the so-called "draft-martini" protocol, which has since been superseded by the Pseudowire Emulation Edge to Edge Working Group specifications described in RFC 4447 and related documents. This memo defines a Historic Document for the Internet community.

This document describes protocol-specific procedures and extensions for Generalized Multi-Protocol Label Switching (GMPLS) Resource ReSerVation Protocol - Traffic Engineering (RSVP-TE) signaling to support end-to-end Label Switched Path (LSP) recovery that denotes protection and restoration. A generic functional description of GMPLS recovery can be found in a companion document, RFC 4426. [STANDARDS-TRACK]

This document describes protocol specific procedures for GMPLS (Generalized Multi-Protocol Label Switching) RSVP-TE (Resource ReserVation Protocol - Traffic Engineering) signaling extensions to support label switched path (LSP) segment protection and restoration. These extensions are intended to complement and be consistent with the RSVP-TE Extensions for End-to-End GMPLS Recovery (RFC 4872). Implications and interactions with fast reroute are also addressed. This document also updates the handling of NOTIFY_REQUEST objects. [STANDARDS-TRACK]

This document provides encapsulation formats and semantics for emulating Synchronous Optical Network/Synchronous Digital Hierarchy (SONET/SDH) circuits and services over MPLS. [STANDARDS-TRACK]

This document specifies ways to communicate route exclusions during path setup using Resource ReserVation Protocol-Traffic Engineering (RSVP-TE).

The RSVP-TE specification, "RSVP-TE: Extensions to RSVP for LSP Tunnels" (RFC 3209) and GMPLS extensions to RSVP-TE, "Generalized Multi-Protocol Label Switching (GMPLS) Signaling Resource ReserVation Protocol-Traffic Engineering (RSVP-TE) Extensions" (RFC 3473) allow abstract nodes and resources to be explicitly included in a path setup, but not to be explicitly excluded.

In some networks where precise explicit paths are not computed at the head end, it may be useful to specify and signal abstract nodes and resources that are to be explicitly excluded from routes. These exclusions may apply to the whole path, or to parts of a path between two abstract nodes specified in an explicit path. How Shared Risk Link Groups (SRLGs) can be excluded is also specified in this document. [STANDARDS-TRACK]

This document defines a Management Information Base (MIB) module that contains textual conventions (TCs) to represent commonly used Generalized Multiprotocol Label Switching (GMPLS) management information. The intent is that these textual conventions will be imported and used in GMPLS-related MIB modules that would otherwise define their own representations. [STANDARDS-TRACK]

This memo defines a portion of the Management Information Base (MIB) for use with network management protocols in the Internet community. In particular, it describes managed objects for Generalized Multiprotocol Label Switching (GMPLS)-based traffic engineering. [STANDARDS-TRACK]

This memo defines a portion of the Management Information Base (MIB) for use with network management protocols in the Internet community. In particular, it describes managed objects to configure and/or monitor a Generalized Multiprotocol Label Switching (GMPLS) Label Switching Router (LSR). [STANDARDS-TRACK]

This document describes an extension to Generalized MPLS (Multi-Protocol Label Switching) signaling to support communication of alarm information. GMPLS signaling already supports the control of alarm reporting, but not the communication of alarm information. This document presents both a functional description and GMPLS-RSVP specifics of such an extension. This document also proposes modification of the RSVP ERROR_SPEC object.

This document updates RFC 3473, "Generalized Multi-Protocol Label Switching (GMPLS) Signaling Resource ReserVation Protocol-Traffic Engineering (RSVP-TE) Extensions", through the addition of new, optional protocol elements. It does not change, and is fully backward compatible with, the procedures specified in RFC 3473. [STANDARDS-TRACK]

This document provides a framework for establishing and controlling Multiprotocol Label Switching (MPLS) and Generalized MPLS (GMPLS) Traffic Engineered (TE) Label Switched Paths (LSPs) in multi-domain networks.

For the purposes of this document, a domain is considered to be any collection of network elements within a common sphere of address management or path computational responsibility. Examples of such domains include Interior Gateway Protocol (IGP) areas and Autonomous Systems (ASes). This memo provides information for the Internet community.

This document defines a mechanism for the reoptimization of loosely routed MPLS and GMPLS (Generalized Multiprotocol Label Switching) Traffic Engineering (TE) Label Switched Paths (LSPs) signaled with Resource Reservation Protocol Traffic Engineering (RSVP-TE). This document proposes a mechanism that allows a TE LSP head-end Label Switching Router (LSR) to trigger a new path re-evaluation on every hop that has a next hop defined as a loose or abstract hop and a mid-point LSR to signal to the head-end LSR that a better path exists (compared to the current path) or that the TE LSP must be reoptimized (because of maintenance required on the TE LSP path). The proposed mechanism applies to the cases of intra- and inter-domain (Interior Gateway Protocol area (IGP area) or Autonomous System) packet and non-packet TE LSPs following a loosely routed path. This memo provides information for the Internet community.

The Generalized MPLS (GMPLS) suite of protocols has been defined to control different switching technologies as well as different applications. These include support for requesting TDM connections including Synchronous Optical Network/Synchronous Digital Hierarchy (SONET/SDH) and Optical Transport Networks (OTNs).

This document provides an evaluation of the IETF Routing Protocols against the routing requirements for an Automatically Switched Optical Network (ASON) as defined by ITU-T. This memo provides information for the Internet community.