Pals Workgroup RFCs

Browse Pals Workgroup RFCs by Number

RFC7708 - Using a Generic Associated Channel Label as a Virtual Circuit Connectivity Verification Channel Indicator

The Virtual Circuit Connectivity Verification (VCCV) protocol specified in RFC 5085 provides a control channel (CC) that is associated with a pseudowire (PW). This document specifies an additional VCCV control channel type to be used with pseudowires that do not use the PW Control Word and that are carried over an MPLS network. This new VCCV CC type uses the Generic Associated Channel Label defined in RFC 5586 to distinguish VCCV packets from packets carrying user data. This new VCCV CC type introduces compatibility with the method of MPLS Label Switched Path Operations, Administration, and Maintenance (OAM) identification, particularly in MPLS Transport Profile (MPLS-TP) networks (RFC 5921).

RFC7727 - Spanning Tree Protocol (STP) Application of the Inter-Chassis Communication Protocol (ICCP)

The Inter-Chassis Communication Protocol (ICCP) supports an inter-chassis redundancy mechanism that is used to support high network availability.

In this document, Provider Edge (PE) devices in a Redundancy Group (RG) running ICCP are used to offer multihomed connectivity to Spanning Tree Protocol (STP) networks to improve availability of the STP networks. The ICCP TLVs and usage for the ICCP STP application are defined.

RFC7769 - Media Access Control (MAC) Address Withdrawal over Static Pseudowire

This document specifies a mechanism to signal Media Access Control (MAC) address withdrawal notification using a pseudowire (PW) Associated Channel (ACH). Such notification is useful when statically provisioned PWs are deployed in a Virtual Private LAN Service (VPLS) or Hierarchical Virtual Private LAN Service (H-VPLS) environment.

RFC7771 - Switching Provider Edge (S-PE) Protection for MPLS and MPLS Transport Profile (MPLS-TP) Static Multi-Segment Pseudowires

In MPLS and MPLS Transport Profile (MPLS-TP) environments, statically provisioned Single-Segment Pseudowires (SS-PWs) are protected against tunnel failure via MPLS-level and MPLS-TP-level tunnel protection. With statically provisioned Multi-Segment Pseudowires (MS-PWs), each segment of the MS-PW is likewise protected from tunnel failures via MPLS-level and MPLS-TP-level tunnel protection. However, static MS-PWs are not protected end-to-end against failure of one of the Switching Provider Edge Routers (S-PEs) along the path of the MS-PW. This document describes how to achieve this protection via redundant MS-PWs by updating the existing procedures in RFC 6870. It also contains an optional approach based on MPLS-TP Linear Protection.

RFC7795 - Pseudowire Redundancy on the Switching Provider Edge (S-PE)

This document describes Multi-Segment Pseudowire (MS-PW) protection scenarios in which pseudowire redundancy is provided on the Switching Provider Edge (S-PE) as defined in RFC 5659. Operations of the S-PEs that provide PW redundancy are specified in this document. Signaling of the Preferential Forwarding status as defined in RFCs 6870 and 6478 is reused. This document does not require any change to the Terminating Provider Edges (T-PEs) of MS-PW.

RFC7796 - Ethernet-Tree (E-Tree) Support in Virtual Private LAN Service (VPLS)

This document specifies a generic Virtual Private LAN Service (VPLS) solution, which uses VLANs to indicate root or leaf traffic to support Ethernet-Tree (E-Tree) services. A VPLS Provider Edge (PE) model is illustrated as an example for the solution. In the solution, E-Tree VPLS PEs are interconnected by Pseudowires (PWs), which carry the VLAN indicating the E-Tree attribute. The MAC address-based Ethernet forwarding engine and the PW work in the same way as specified in RFC 4762 and RFC 4448, respectively. A signaling mechanism is described to support E-Tree capability and VLAN mapping negotiation.

RFC7885 - Seamless Bidirectional Forwarding Detection (S-BFD) for Virtual Circuit Connectivity Verification (VCCV)

This document defines Seamless BFD (S-BFD) for VCCV by extending the procedures and Connectivity Verification (CV) types already defined for Bidirectional Forwarding Detection (BFD) for Virtual Circuit Connectivity Verification (VCCV).

This document updates RFC 5885 by extending the CV Type values and the capability selection.

RFC7893 - Pseudowire Congestion Considerations

Pseudowires (PWs) have become a common mechanism for tunneling traffic and may be found in unmanaged scenarios competing for network resources both with other PWs and with non-PW traffic, such as TCP/IP flows. Thus, it is worthwhile specifying under what conditions such competition is acceptable, i.e., the PW traffic does not significantly harm other traffic or contribute more than it should to congestion. We conclude that PWs transporting responsive traffic behave as desired without the need for additional mechanisms. For inelastic PWs (such as Time Division Multiplexing (TDM) PWs), we derive a bound under which such PWs consume no more network capacity than a TCP flow. For TDM PWs, we find that the level of congestion at which the PW can no longer deliver acceptable TDM service is never significantly greater, and is typically much lower, than this bound. Therefore, as long as the PW is shut down when it can no longer deliver acceptable TDM service, it will never do significantly more harm than even a single TCP flow. If the TDM service does not automatically shut down, a mechanism to block persistently unacceptable TDM pseudowires is required.

RFC7965 - LDP Extensions for Pseudowire Binding to Label Switched Path (LSP) Tunnels

Many transport services require that user traffic, in the form of Pseudowires (PWs), be delivered via either a single co-routed bidirectional tunnel or two unidirectional tunnels that share the same routes. This document defines an optional extension to the Label Distribution Protocol (LDP) that enables the binding between PWs and the underlying Traffic Engineering (TE) tunnels. The extension applies to both single-segment and multi-segment PWs.

RFC8024 - Multi-Chassis Passive Optical Network (MC-PON) Protection in MPLS

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.

RFC8077 - Pseudowire Setup and Maintenance Using the Label Distribution Protocol (LDP)

Layer 2 services (such as Frame Relay, Asynchronous Transfer Mode, and Ethernet) can be emulated over an MPLS backbone by encapsulating the Layer 2 Protocol Data Units (PDUs) and then transmitting them over pseudowires (PWs). It is also possible to use pseudowires to provide low-rate Time-Division Multiplexed and Synchronous Optical NETworking circuit emulation over an MPLS-enabled network. This document specifies a protocol for establishing and maintaining the pseudowires, using extensions to the Label Distribution Protocol (LDP). Procedures for encapsulating Layer 2 PDUs are specified in other documents.

This document is a rewrite of RFC 4447 for publication as an Internet Standard.

RFC8104 - Pseudowire (PW) Endpoint Fast Failure Protection

This document specifies a fast mechanism for protecting pseudowires (PWs) transported by IP/MPLS tunnels against egress endpoint failures, including egress attachment circuit (AC) failure, egress provider edge (PE) failure, multi-segment PW terminating PE failure, and multi-segment PW switching PE failure. Operating on the basis of multihomed customer edge (CE), redundant PWs, upstream label assignment, and context-specific label switching, the mechanism enables local repair to be performed by the router upstream adjacent to a failure. The router can restore a PW in the order of tens of milliseconds, by rerouting traffic around the failure to a protector through a pre-established bypass tunnel. Therefore, the mechanism can be used to reduce traffic loss before global repair reacts to the failure and the network converges on the topology changes due to the failure.

RFC8184 - Dual-Homing Protection for MPLS and the MPLS Transport Profile (MPLS-TP) Pseudowires

This document describes a framework and several scenarios for a pseudowire (PW) dual-homing local protection mechanism that avoids unnecessary switchovers and does not depend on whether a control plane is used. A Dual-Node Interconnection (DNI) PW is used to carry traffic between the dual-homing Provider Edge (PE) nodes when a failure occurs in one of the Attachment Circuits (AC) or PWs. This PW dual-homing local protection mechanism is complementary to existing PW protection mechanisms.

RFC8185 - Dual-Homing Coordination for MPLS Transport Profile (MPLS-TP) Pseudowires Protection

In some scenarios, MPLS Transport Profile (MPLS-TP) pseudowires (PWs) (RFC 5921) may be statically configured when a dynamic control plane is not available. A fast protection mechanism for MPLS-TP PWs is needed to protect against the failure of an Attachment Circuit (AC), the failure of a Provider Edge (PE), or a failure in the Packet Switched Network (PSN). The framework and typical scenarios of dual- homing PW local protection are described in RFC 8184. This document proposes a dual-homing coordination mechanism for MPLS-TP PWs that is used for state exchange and switchover coordination between the dual- homing PEs for dual-homing PW local protection.

RFC8220 - Protocol Independent Multicast (PIM) over Virtual Private LAN Service (VPLS)

This document describes the procedures and recommendations for Virtual Private LAN Service (VPLS) Provider Edges (PEs) to facilitate replication of multicast traffic to only certain ports (behind which there are interested Protocol Independent Multicast (PIM) routers and/or Internet Group Management Protocol (IGMP) hosts) via PIM snooping and proxying.

With PIM snooping, PEs passively listen to certain PIM control messages to build control and forwarding states while transparently flooding those messages. With PIM proxying, PEs do not flood PIM Join/Prune messages but only generate their own and send them out of certain ports, based on the control states built from downstream Join/Prune messages. PIM proxying is required when PIM Join suppression is enabled on the Customer Edge (CE) devices and is useful for reducing PIM control traffic in a VPLS domain.

This document also describes PIM relay, which can be viewed as lightweight proxying, where all downstream Join/Prune messages are simply forwarded out of certain ports and are not flooded, thereby avoiding the triggering of PIM Join suppression on CE devices.

RFC8237 - MPLS Label Switched Path (LSP) Pseudowire (PW) Status Refresh Reduction for Static PWs

This document describes a method for generating an aggregated pseudowire (PW) status message transmitted for a statically configured PW on a Multiprotocol Label Switching (MPLS) Label Switched Path (LSP) to indicate the status of one or more PWs carried on the LSP.

The method for transmitting the PW status information is not new; however, this protocol extension allows a Service Provider (SP) to reliably monitor the individual PW status while not overwhelming the network with multiple periodic status messages. This is achieved by sending a single cumulative summary status verification message for all the PWs grouped in the same LSP.

RFC8338 - Signaling Root-Initiated Point-to-Multipoint Pseudowire Using LDP

This document specifies a mechanism to signal Point-to-Multipoint (P2MP) Pseudowire (PW) trees using LDP. Such a mechanism is suitable for any Layer 2 VPN service requiring P2MP connectivity over an IP or MPLS-enabled PSN. A P2MP PW established via the proposed mechanism is root initiated. This document updates RFC 7385 by reassigning the reserved value 0xFF to be the wildcard transport tunnel type.

RFC8339 - Definition of P2MP PW TLV for Label Switched Path (LSP) Ping Mechanisms

Label Switched Path (LSP) Ping is a widely deployed Operation, Administration, and Maintenance (OAM) mechanism in MPLS networks. This document describes a mechanism to verify connectivity of Point-to-Multipoint (P2MP) Pseudowires (PWs) using LSP Ping.

RFC8469 - Recommendation to Use the Ethernet Control Word

The pseudowire (PW) encapsulation of Ethernet, as defined in RFC 4448, specifies that the use of the control word (CW) is optional. In the absence of the CW, an Ethernet PW packet can be misidentified as an IP packet by a label switching router (LSR). This may lead to the selection of the wrong equal-cost multipath (ECMP) path for the packet, leading in turn to the misordering of packets. This problem has become more serious due to the deployment of equipment with Ethernet Media Access Control (MAC) addresses that start with 0x4 or 0x6. The use of the Ethernet PW CW addresses this problem. This document RECOMMENDS the use of the Ethernet PW CW in all but exceptional circumstances.

This document updates RFC 4448.