Network Working Group F. Zhang, Ed. Internet-Draft Huawei Intended status: Standards Track B. Wu, Ed. Expires: December 26, 2015 ZTE Corporation E. Bellagamba, Ed. Ericsson M. Chen, Ed. Huawei June 24, 2015 Label Distribution Protocol Extensions for Proactive Operations, Administration and Maintenance Configuration of Dynamic MPLS Transport Profile PseudoWire draft-ietf-pals-mpls-tp-oam-config-01 Abstract This document defines extensions to LDP to configure proactive OAM functions for both dynamic SS-PW and MS-PW. Status of This Memo This Internet-Draft is submitted in full conformance with the provisions of BCP 78 and BCP 79. Internet-Drafts are working documents of the Internet Engineering Task Force (IETF). Note that other groups may also distribute working documents as Internet-Drafts. The list of current Internet- Drafts is at http://datatracker.ietf.org/drafts/current/. Internet-Drafts are draft documents valid for a maximum of six months and may be updated, replaced, or obsoleted by other documents at any time. It is inappropriate to use Internet-Drafts as reference material or to cite them other than as "work in progress." This Internet-Draft will expire on December 26, 2015. Copyright Notice Copyright (c) 2015 IETF Trust and the persons identified as the document authors. All rights reserved. This document is subject to BCP 78 and the IETF Trust's Legal Provisions Relating to IETF Documents (http://trustee.ietf.org/license-info) in effect on the date of publication of this document. Please review these documents carefully, as they describe your rights and restrictions with respect Zhang, et al. Expires December 26, 2015 [Page 1] Internet-Draft LDP Extensions for TP PW OAM June 2015 to this document. Code Components extracted from this document must include Simplified BSD License text as described in Section 4.e of the Trust Legal Provisions and are provided without warranty as described in the Simplified BSD License. Table of Contents 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2 2. Conventions used in this document . . . . . . . . . . . . . . 3 2.1. Acronyms . . . . . . . . . . . . . . . . . . . . . . . . 3 3. MPLS-TP PW OAM Configuration . . . . . . . . . . . . . . . . 5 3.1. OAM Configuration for MS-PW . . . . . . . . . . . . . . . 5 3.1.1. Establishment of OAM Entities and Functions . . . . . 5 3.1.2. Adjustment of OAM Parameters . . . . . . . . . . . . 7 3.1.3. Deleting OAM Entities . . . . . . . . . . . . . . . . 8 3.2. OAM Configuration for SS-PW . . . . . . . . . . . . . . . 8 4. LDP Extensions . . . . . . . . . . . . . . . . . . . . . . . 9 4.1. MPLS-TP PW OAM Administration TLV . . . . . . . . . . . . 9 4.2. MPLS-TP PW OAM Configuration TLV . . . . . . . . . . . . 10 4.2.1. BFD Configuration sub-TLV . . . . . . . . . . . . . . 11 4.2.1.1. Local Discriminator sub-TLV . . . . . . . . . . . 12 4.2.1.2. Negotiation Timer Parameters sub-TLV . . . . . . 13 4.2.1.3. BFD Authentication sub-TLV . . . . . . . . . . . 14 4.2.2. Performance Monitoring sub-TLV . . . . . . . . . . . 14 4.2.2.1. MPLS-TP PW PM Loss TLV . . . . . . . . . . . . . 16 4.2.2.2. MPLS-TP PW PM Delay TLV . . . . . . . . . . . . . 17 4.2.3. MPLS-TP PW FMS sub-TLV . . . . . . . . . . . . . . . 18 5. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 19 5.1. TLV . . . . . . . . . . . . . . . . . . . . . . . . . . . 19 5.1.1. MPLS-TP PW OAM Configuration Sub-TLV . . . . . . . . 19 5.1.1.1. BFD Configuration sub-TLVs . . . . . . . . . . . 19 5.1.1.2. Performance Monitoring sub-TLVs . . . . . . . . . 19 5.2. OAM Configuration Error Code . . . . . . . . . . . . . . 20 6. Security Considerations . . . . . . . . . . . . . . . . . . . 20 7. Acknowledgement . . . . . . . . . . . . . . . . . . . . . . . 20 8. References . . . . . . . . . . . . . . . . . . . . . . . . . 20 8.1. Normative references . . . . . . . . . . . . . . . . . . 20 8.2. Informative References . . . . . . . . . . . . . . . . . 21 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 22 1. Introduction MultiProtocol Label Switching (MPLS) Pseudowire (PW) is defined in [RFC3985] and [RFC5659], which provides emulated services over an MPLS Packet Switched Network (PSN). MPLS Transport Profile (MPLS-TP) describes a profile of MPLS that introduces the operational models typically used in transport networks, while providing additional Operations, Administration and Maintenance (OAM), survivability and Zhang, et al. Expires December 26, 2015 [Page 2] Internet-Draft LDP Extensions for TP PW OAM June 2015 other maintenance functions that are not previously supported by IP/ MPLS network. The corresponding requirements are defined in [RFC5860]. The MPLS-TP OAM mechanisms are described in [RFC6371], which can be categorized into proactive and on-demand OAM. Proactive OAM refers to OAM operations that are either configured to be carried out periodically and continuously or preconfigured to act on certain events (e.g., alarm signals). In contrast, on-demand OAM is initiated manually and for a limited amount of time, usually for operations such as diagnostics to investigate into a defect condition. Normally, the Network Management System (NMS) is used to configure these OAM functionalities when a control plane is not instantiated. If the control plane is used, as required in [RFC5654] (Requirement 51), it MUST support the configuration and modification of OAM maintenance points as well as the activation/deactivation of OAM when the transport path or transport service is established or modified. This document defines extensions to the Label Distribution Protocol (LDP) protocol to configure and bootstrap proactive PW OAM functions, which are suitable for both Point to Point (P2P) Single-Segment PseudoWire (SS-PW) and Multi-Segment PseudoWire (MS-PW). The extensions to Point to Multi-Point (P2MP) PW is left for future study and out of scope. 2. Conventions used in this document The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this document are to be interpreted as described in [RFC2119]. 2.1. Acronyms AC: Attachment Circuit AIS: Alarm indication signal BFD: Bidirectional Forwarding Detection CC: Continuity Check CV: Connectivity Verification DM: Delay Measurement FEC: Forwarding Equivalence Class Zhang, et al. Expires December 26, 2015 [Page 3] Internet-Draft LDP Extensions for TP PW OAM June 2015 FMS: Fault Management Signal ICMP: Internet Control Message Protocol G-ACh: Generic Associated Channel LDI: Link Down Indication LDP: Label Distribution Protocol LKR: Lock Reporting LM: Loss Measurement LSP: Label Switched Path ME: Maintenance Entity MEG: Maintenance Entity Group MEP: Maintenance Entity Group End Point MIP: Maintenance Entity Group Intermediate Point MPLS-TP: MPLS Transport Profile MS-PW: Multi-Segment PseudoWire NMS: Network Management System OAM: Operations, Administration and Maintenance P2MP: Point to Multi-Point PE: Provider Edge PHB: Per-Hop Behavior PM: Performance Monitoring PSN: Packet Switched Network PW: Pseudowire S-PE: Switching Provider Edge SPME: Sub-Path Maintenance Entity Zhang, et al. Expires December 26, 2015 [Page 4] Internet-Draft LDP Extensions for TP PW OAM June 2015 SS-PW: Single-Segment Pseudo Wire T-PE: Terminating Provider Edge TLV: Type Length Value VCCV: Virtual Circuit Connectivity Verification 3. MPLS-TP PW OAM Configuration For SS-PW and MS-PW, the OAM configuration procedures are almost identical. Section 3.1 describes the OAM configuration procedures for MS-PW. Section 3.2 highlights the differences between SS-PW and MS-PW. 3.1. OAM Configuration for MS-PW 3.1.1. Establishment of OAM Entities and Functions Given that there is a PW that needs to be setup between T-PE1 and T-PE2, across S-PE1 and S-PE2 (as shown below in Figure 1) . OAM functions MUST be setup and enabled in the appropriate order so that spurious alarms can be avoided. +-------+ +-------+ +-------+ +-------+ | | | | | | | | | A|--------|B C|--------|D E|--------|F | | | | | | | | | +-------+ +-------+ +-------+ +-------+ T-PE1 S-PE1 S-PE2 T-PE2 Figure 1 MS-PW Scenario Figure 1: MS-PW OAM Configuration Scheme Fist of all, T-PE1 MUST setup the OAM sink function and prepare to receive OAM messages. Before the PW established, any OAM alarms MUST be suppressed. To achieve this, a Label Mapping message MUST be sent with the "OAM Alarms Enabled" flag cleared. If the S-PEs are expected to establish and enable the MIP entities, the "OAM MIP Entities desired" of the MPLS-TP PW OAM Administration TLV MUST be set. In addition, the "OAM MEP Entities Desired" flag MUST be set, the MPLS-TP PW OAM Configuration TLV and related sub-TLVs MUST be included to configure and enable particular OAM functions. On receipt of the Label Mapping message, S-PE(e.g., S-PE1) SHOULD establish and configure MIP functions according to the "OAM MIP Entities desired" flag in the MPLS-TP PW OAM Administration TLV. If Zhang, et al. Expires December 26, 2015 [Page 5] Internet-Draft LDP Extensions for TP PW OAM June 2015 the MIP functions are established and configured successfully, S-PE1 will relay the Label Mapping message downstream to the next S-PE. Otherwise, a Label Release message MUST be replied to its upstream adjacent PE, with a Status Code set to "MIP Configuration Failure", and the PW will not be established. All the subsequent S-PEs along the PW will perform the same operations as S-PE1 does until the Label Mapping message reaches to the remote T-PE (T-PE2). When the Mapping message arrives at the remote T-PE (T-PE2), T-PE2 MUST establish and configure OAM entities according to the information carried in the MPLS-TP PW OAM Administration TLV and MPLS-TP PW OAM Configuration TLV. If T-PE2 fails to establish and configure the OAM entities, a Label Release message MUST be replied to its upstream PE, with a Status Code set to "Fail to Establish and Configure OAM Entities". If the OAM entities established and configured successfully, the OAM sink and source functions MUST be setup and the OAM sink function MUST be prepared to receive OAM messages. Since the OAM alarm is disabled, no alarms will be generated. The OAM source function can start to send OAM messages. The same rules are applied to the reverse direction (from T-PE2 to T-PE1). Specifically, T-PE2 needs to setup the OAM sink function and prepare to receive OAM messages. OAM alarms MUST be suppressed by sending a Label Mapping message carrying an MPLS-TP PW OAM Administration TLV with the "OAM Alarms Enabled" cleared. When MIP entities are desired, the "OAM MIP Entities desired" flag of the MPLS-TP PW OAM Administration TLV MUST be set. Then S-PEs MUST establish and configure MIP functions according to the "OAM MIP Entities desired" flag of the MPLS-TP PW OAM Administration TLV. When T-PE1 receives the Label Mapping message, it completes any pending OAM configuration and enables the OAM source function to send OAM messages. Till now, OAM entities are established and configured for the PW and OAM messages may already be exchanged. The OAM alarms can be safely enabled now. The initiator PE (T-PE1) will then send another Label Mapping message with "OAM Alarms Enabled" flag set to enable the OAM alarm function. When T-PE2 received the Label Mapping message, it will enable the OAM alarm and send a Label Mapping message with the "OAM Alarms Enabled" flag set along the reverse direction to T-PE1. Once the Label Mapping message received, T-PE1 enables the OAM alarm function. At this point, data-plane OAM is fully functional. The above shows how the OAM entities are established and configured with the establishment of a PW. It's possible that a PW is established without any OAM entities establishments and configurations when the PW was signalled, and then the OAM entities can be established and configured later. This can be done by sending Zhang, et al. Expires December 26, 2015 [Page 6] Internet-Draft LDP Extensions for TP PW OAM June 2015 another Label Mapping message with the updated configuration parameters. The procedure is identical to the adjustment of OAM parameters, more detail is described in Section 3.1.2. 3.1.2. Adjustment of OAM Parameters There may be a need to change the parameters of an already established and configured OAM function during the lifetime of the PW. To achieve this, the T-PEs need to send a Label Mapping message with the updated OAM parameters to update and adjust relevant parameters. OAM parameters that influence the content and timing of OAM messages and identify the way OAM defects and alarms are derived and generated. To avoid spurious alarms, it is important that both sides, OAM sink and source, are updated in a synchronized way. So, firstly, the alarms of the OAM sink function should be suppressed and only then expected OAM parameters should be adjusted. Subsequently, the parameters of the OAM source function can be updated. Finally, the alarms of the OAM sink side can be enabled again. In accordance with the above operation, T-PE1 MUST send a Label Mapping message with the "OAM Alarms Enabled" flag cleared and including the updated MPLS-TP PW OAM Configuration TLV corresponding to the new parameter settings. The initiator (T-PE1) MUST keep its OAM sink and source functions running unmodified, but it MUST suppress OAM alarms before the updated Label Mapping message is sent. The receiver (T-PE2) MUST firstly disable all OAM alarms, then update the OAM parameters according to the information in the Label Mapping message and reply with a Label Mapping message acknowledging the changes by including the MPLS-TP PW OAM Configuration TLV. Note that the receiving side has the possibility to adjust the requested OAM configuration parameters and reply with and updated MPLS-TP PW OAM Configuration TLV in the Label Mapping message, reflecting the actually configured values. However, in order to avoid an extensive negotiation phase, in the case of adjusting already configured OAM functions, the receiving side SHOULD NOT update the parameters requested in the Label Mapping message to an extent that would provide lower performance than what has been configured previously. The initiator (T-PE1) MUST only update its OAM sink and source functions when it has received the Label Mapping message from the peer. After the OAM parameters are updated and OAM is running according the new parameter settings, OAM alarms are still disabled, so a subsequent Label Mapping messages exchanges with "OAM Alarms Enabled" flag set are needed to enable OAM alarms again. Zhang, et al. Expires December 26, 2015 [Page 7] Internet-Draft LDP Extensions for TP PW OAM June 2015 3.1.3. Deleting OAM Entities In some cases it may be useful to remove some or all OAM entities and functions from a PW without actually tearing down the connection. The deleting procedures are defined as below: Firstly, the initiator PE (e.g., T-PE1) disables the OAM alarms and sends a Label Mapping message to the remote PE (e.g., T-PE2) with the "OAM Alarms Enabled" flag cleared but with all other OAM configuration unchanged. Ofter receiving the acknowledgement of the OAM alarms disable, T-PE1 will send a Label Mapping message with the "OAM MEP Entities desired" and "OAM MIP Entities desired" flags cleared to its adjacent PE to delete all OAM entities associated with the PW. When the Label Mapping message finally reaches the T-PE2, all the OAM entities associated with the PW are deleted and all relevant data-plane and control plane resources in use by the OAM entities and functions should be freed up. 3.2. OAM Configuration for SS-PW For SS-PW, there is no need to establish and enable MIP entities. This is different from the MS-PW OAM configuration mechanisms as described above. In addition, for SS-PW, another difference is that both ends of the PW may be the OAM configuration initiator. It is possible that both ends will try to establish and configure the OAM entities and functions at the same time. If the OAM parameters and functions configured by both ends are the same, then the configuration has converged on a mutually way and the configuration and PW signalling are completed. Otherwise, the configurations from both sides are different. To resolve the confliction, the Label Switching Router (LSR) identifiers (LSR Id) of the PEs are used as the tie breaker. That is, when the configurations conflict, the receiving PE (e.g., T-PE2) MUST compare its LSR Id against the initiator's (T-PE1's). If it is numerically lower, means T-PE1's configuration has the higher priority, T-PE2 will obey the configuration requests from T-PE1 and reply a Label Mapping message with the updated "MPLS-TP PW OAM Configuration TLV" according to the received configuration to acknowledge the configuration. On the other hand, if the T-PE2's LSR Id is numerically higher than T-PE1's, it MUST reply a Label Release message with Status Code set to "Rejected MPLS-TP PW OAM Configuration TLV", and the PW will not be established. Zhang, et al. Expires December 26, 2015 [Page 8] Internet-Draft LDP Extensions for TP PW OAM June 2015 4. LDP Extensions 4.1. MPLS-TP PW OAM Administration TLV The MPLS-TP PW OAM Administration TLV is used to configure and enable the MEP, MIP and Alarm functions. It can be sent with the Label Mapping message. The format of the TLV is as follows: 0 1 2 3 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |0|0| Type | Length(=4) | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | OAM Administration Flags | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ MPLS-TP PW OAM Administration TLV The MPLS-TP PW OAM Administration TLV type is TBD1. The Length field is 2 octets in length. It defines the length in octets of OAM Administration Flags filed, it's value is 4. The OAM Administration Flags is a bitmap with the length of 4 octets. This document defines the following flags: OAM Administration Flags bit# Description ----------------------------- -------------------------------- 0 OAM MIP Entities Desired 1 OAM MEP Entities Desired 2 OAM Alarms Enabled 3-31 Reserved The "OAM MIP Entities Desired" flag is used to direct each S-PE along the PW to establish (when set) or delete (when cleared and the OAM MIP entity exists) the OAM MIP entity. The "OAM MEP Entities Desired" flag is used to request the remote T-PE to establish (when set) or delete (when cleared) the OAM entities. The "OAM Alarms Enabled" flag is used to request the remote T-PE to enable (when set) or disable (when cleared) OAM alarms function. Reserved (3-31 bits): MUST be set to zero on transmission and SHOULD be ignored on receipt. Zhang, et al. Expires December 26, 2015 [Page 9] Internet-Draft LDP Extensions for TP PW OAM June 2015 4.2. MPLS-TP PW OAM Configuration TLV The MPLS-TP PW OAM Configuration TLV is defined to configure and enable specific OAM functions, it is carried in Label Mapping message when used. The format of the TLV is as follows: 0 1 2 3 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |0|0| Type | Length | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | OAM Function Flags | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ ~ sub-TLVs ~ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ MPLS-TP PW OAM Configuration TLV The MPLS-TP PW OAM Configuration TLV contains a number of flags indicating which OAM functions should be activated and OAM function specific sub-TLVs with configuration parameters for particular functions. The MPLS-TP PW OAM Configuration TLV type is TBD2. The Length field is 2 octets in length. It defines the length in octets of OAM Function Flags and sub-TLVs fields. The OAM Function Flags is a bitmap with the length of 4 octets. This document defines the following flags: OAM Function Flags bit# Description --------------------- --------------------------- 0 Continuity Check (CC) 1 Connectivity Verification (CV) 2 Fault Management Signals (FMS) 3 Performance Monitoring (PM) Loss 4 Performance Monitoring (PM) Delay 5 Performance Monitoring (PM) Throughput 6-31 Reserved The sub-TLVs corresponding to the different OAM function flags are as follows. o BFD Configuration sub-TLV MUST be included if the CC and/or the CV OAM Function flag is set. Furthermore, if the CV flag is set, the CC flag MUST be set at the same time. Zhang, et al. Expires December 26, 2015 [Page 10] Internet-Draft LDP Extensions for TP PW OAM June 2015 o Performance Monitoring sub-TLV MUST be included if the PM Loss/ Delay OAM Function flag is set. o MPLS-TP PW FMS sub-TLV MAY be included if the FMS OAM Function flag is set. If the MPLS-TP PW FMS sub-TLV is not included, the default configuration values are used. 4.2.1. BFD Configuration sub-TLV The BFD Configuration sub-TLV is defined for BFD specific configuration parameters, which accommodates generic BFD OAM information and carries sub-TLVs. 0 1 2 3 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Type (1) | Length | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |Vers.| PHB |N|S|I|G|U|A| Reserved (set to all 0s) | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | | ~ sub TLVs ~ | | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ BFD Configuration sub-TLV Type: The "BFD Configuration sub-TLV" type is 1. Length: It defines the length in octets of the value field. Version: It identifies the BFD protocol version. If a node does not support a specific BFD version, a Notification message MUST be generated with Status Code set to "Unsupported OAM Version". PHB: Identifies the Per-Hop Behavior (PHB) to be used for periodic continuity monitoring messages. BFD Negotiation (N): If set, timer negotiation/re-negotiation via BFD Control Messages is enabled, when cleared it is disabled. Symmetric session (S): If set, the BFD session MUST use symmetric timing values. Integrity (I): If set, BFD Authentication MUST be enabled. If the "BFD Configuration sub-TLV" does not include a "BFD Authentication sub-TLV" the authentication MUST use Keyed SHA1 with an empty pre- shared key (all 0s). Zhang, et al. Expires December 26, 2015 [Page 11] Internet-Draft LDP Extensions for TP PW OAM June 2015 Encapsulation Capability (G): if set, it shows the capability of encapsulating BFD messages into G-ACh channel without IP/UDP headers. If both the G bit and U bit are set, configuration gives precedence to the G bit. Encapsulation Capability (U): if set, it shows the capability of encapsulating BFD messages into G-ACh channel with IP/UDP headers. If both the G bit and U bit are set, configuration gives precedence to the G bit. Operation mode (A): if set, it configures BFD in the associated mode. If it is not set it configures BFD in independent mode. Reserved: Reserved for future specification and set to 0. The BFD Configuration sub-TLV MUST include the following sub-TLVs in the Mapping message: o Local Discriminator sub-TLV. o Negotiation Timer Parameters sub-TLV if the N flag is cleared. 4.2.1.1. Local Discriminator sub-TLV The Local Discriminator sub-TLV is carried as a sub-TLV of the BFD Configuration sub-TLV and is depicted below. 0 1 2 3 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Lcl. Discr. Type (1) | Length (4) | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Local Discriminator | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ Local Discriminator sub-TLV Type: The "Local Discriminator sub-TLV" type is 1. Length: indicates the TLV total length in octets (4). Local Discriminator: A unique, nonzero discriminator value generated by the transmitting system and referring to itself, used to demultiplex multiple BFD sessions between the same pair of systems. Zhang, et al. Expires December 26, 2015 [Page 12] Internet-Draft LDP Extensions for TP PW OAM June 2015 4.2.1.2. Negotiation Timer Parameters sub-TLV The "Negotiation Timer Parameters sub-TLV" is carried as a sub-TLV of the "BFD Configuration sub-TLV" and is depicted below. 0 1 2 3 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Timer Neg. Type (2) | Length (16) | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Acceptable Min. Asynchronous TX interval | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Acceptable Min. Asynchronous RX interval | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Required Echo TX Interval | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ Negotiation Timer Parameters sub-TLV Type: The "Negotiation Timer Parameters sub-TLV" type is 2. Length: indicates the TLV total length in octets (16). Acceptable Min. Asynchronous TX interval: in case of S (symmetric) flag set in the "BFD Configuration" TLV, it expresses the desired time interval (in microseconds) at which the T-PE initiating the signalling intends to both transmit and receive BFD periodic control packets. If the receiving T-PE can not support such value, it is allowed to reply back with an interval greater than the one proposed. In case of S (symmetric) flag cleared in the "BFD Configuration sub- TLV", this field expresses the desired time interval (in microseconds) at which T-PE intends to transmit BFD periodic control packets in its transmitting direction. Acceptable Min. Asynchronous RX interval: in case of S (symmetric) flag set in the "BFD Configuration sub-TLV", this field MUST be equal to "Acceptable Min. Asynchronous TX interval" and has no additional meaning respect to the one described for "Acceptable Min.Asynchronous TX interval". In case of S (symmetric) flag cleared in the "BFD Configuration sub- TLV", it expresses the minimum time interval (in microseconds) at which T-PE can receive BFD periodic control packets. In case this value is greater than the "Acceptable Min. Asynchronous TX interval" received from the other T-PE, such T-PE MUST adopt the interval expressed in this "Acceptable Min. Asynchronous RX interval". Zhang, et al. Expires December 26, 2015 [Page 13] Internet-Draft LDP Extensions for TP PW OAM June 2015 Required Echo TX Interval: the minimum interval (in microseconds) between received BFD Echo packets that this system is capable of supporting, less any jitter applied by the sender as described in [RFC5880] sect. 6.8.9. This value is also an indication for the receiving system of the minimum interval between transmitted BFD Echo packets. If this value is zero, the transmitting system does not support the receipt of BFD Echo packets. If the receiving system can not support this value a Notification MUST be generated with Status Code set to "Unsupported BFD TX Echo rate interval". By default the value is set to 0. 4.2.1.3. BFD Authentication sub-TLV The "BFD Authentication sub-TLV" is carried as a sub-TLV of the "BFD Configuration sub-TLV" and is depicted below. 0 1 2 3 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | BFD Auth. Type (3) | Length = 8 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Auth Type | Auth Key ID | Reserved (0s) | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ BFD Authentication sub-TLV Type: The "BFD Authentication sub-TLV" type is 3. Length: indicates the TLV total length in octets (8). Auth Type: indicates which type of authentication to use. The same values as are defined in section 4.1 of [RFC5880] are used. Auth Key ID: indicates which authentication key or password (depending on Auth Type) should be used. How the key exchange is performed is out of scope of this document. Reserved: Reserved for future specification and set to 0. 4.2.2. Performance Monitoring sub-TLV If the "MPLS-TP PW OAM Configuration TLV" has either the PM Loss or PM Delay flag set, the "Performance Monitoring sub-TLV" MUST be present. In case the values need to be different than the default ones, the "MPLS-TP PW PM Loss sub-TLV" and "MPLS-TP PW PM Delay sub-TLV" MUST be included: Zhang, et al. Expires December 26, 2015 [Page 14] Internet-Draft LDP Extensions for TP PW OAM June 2015 o "MPLS-PW PM Loss sub-TLV" if the L flag is set in the "MPLS-TP PW OAM Configuration TLV"; o "MPLS-PW PM Delay sub-TLV" if the D flag is set in the "MPLS-TP PW OAM Configuration TLV ". The "Performance Monitoring sub-TLV" depicted below is carried as a sub-TLV of the "MPLS-TP PW OAM Configuration TLV" 0 1 2 3 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Perf Monitoring Type | Length | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |D|L|J|Y|K|C| Reserved (set to all 0s) | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | | ~ sub-TLVs ~ | | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ Performance Monitoring sub-TLV Type: The "Performance Monitoring sub-TLV" type is 2. Length: indicates the TLV total length in octets. Performance Monitoring sub-TLV has 32-bit flag field, this document defines the following flags: o D: Delay inferred/direct (0=INFERRED, 1=DIRECT) o L: Loss inferred/direct (0=INFERRED, 1=DIRECT) o J: Delay variation/jitter (1=ACTIVE, 0=NOT ACTIVE) o Y: Dyadic (1=ACTIVE, 0=NOT ACTIVE) o K: Loopback (1=ACTIVE, 0=NOT ACTIVE) o C: Combined (1=ACTIVE, 0=NOT ACTIVE) o Other bits are reserved and MUST be set to 0 when sent and should be ignored when received. Sub-TLVs: This document defines two sub-TLVs, more detail in following sub-sections. Zhang, et al. Expires December 26, 2015 [Page 15] Internet-Draft LDP Extensions for TP PW OAM June 2015 4.2.2.1. MPLS-TP PW PM Loss TLV The "MPLS-TP PW PM Loss sub-TLV" depicted below is carried as a sub- TLV of the "Performance Monitoring sub-TLV". 0 1 2 3 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | PM Loss Type (2) | Length | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | OTF |T|B| RESERVED | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Measurement Interval | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Test Interval | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Loss Threshold | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ MPLS-TP PW PM Loss sub-TLV Type: The "MPLS-TP PW PM Loss sub-TLV" type is 2. Length: indicates the length of the parameters in octets. OTF: Origin Timestamp Format of the Origin Timestamp field described in [RFC6374]. By default it is set to IEEE 1588 version 1. Configuration Flags, please refer to [RFC6374] for further details: o T: Traffic-class-specific measurement indicator. Set to 1 when the measurement operation is scoped to packets of a particular traffic class (DSCP value), and 0 otherwise. When set to 1, the DS field of the message indicates the measured traffic class. By default it is set to 1. o B: Octet (byte) count. When set to 1, indicates that the Counter 1-4 fields represent octet counts. When set to 0, indicates that the Counter 1-4 fields represent packet counts. By default it is set to 0. Measurement Interval: the time interval (in microseconds) at which LM query messages MUST be sent on both directions. If the T-PE receiving the Mapping message can not support such value, it can reply back with a higher interval. By default it is set to (TBD). Test Interval: test messages interval as described in [RFC6374]. By default it is set to (TBD). Zhang, et al. Expires December 26, 2015 [Page 16] Internet-Draft LDP Extensions for TP PW OAM June 2015 Loss Threshold: the threshold value of lost packets over which protections MUST be triggered. By default it is set to (TBD). 4.2.2.2. MPLS-TP PW PM Delay TLV The "MPLS-TP PW PM Delay sub-TLV" depicted below is carried as a sub- TLV of the "MPLS-TP PW OAM Configuration TLV" 0 1 2 3 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | PM Delay Type (3) | Length | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | OTF |T|B| RESERVED | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Measurement Interval | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Test Interval | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Delay Threshold | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ MPLS-TP PW PM Delay sub-TLV Type: The "MPLS-TP PW PM Delay sub-TLV" type is 3. Length: indicates the length of the parameters in octets. OTF: Origin Timestamp Format of the Origin Timestamp field described in [RFC6374]. By default it is set to IEEE 1588 version 1. Configuration Flags, please refer to [RFC6374] for further details: o T: Traffic-class-specific measurement indicator. Set to 1 when the measurement operation is scoped to packets of a particular traffic class (DSCP value), and 0 otherwise. When set to 1, the DS field of the message indicates the measured traffic class. By default it is set to 1. o B: Octet (byte) count. When set to 1, indicates that the Counter 1-4 fields represent octet counts. When set to 0, indicates that the Counter 1-4 fields represent packet counts. By default it is set to 0. Measurement Interval: the time interval (in microseconds) at which LM query messages MUST be sent on both directions. If the T-PE receiving the Mapping message can not support such value, it can reply back with a higher interval. By default it is set to (TBD). Zhang, et al. Expires December 26, 2015 [Page 17] Internet-Draft LDP Extensions for TP PW OAM June 2015 Test Interval: test messages interval as described in [RFC6374]. By default it is set to (TBD). Delay Threshold: the threshold value of packet delay time over which protections MUST be triggered. By default it is set to (TBD). 4.2.3. MPLS-TP PW FMS sub-TLV The "MPLS-TP PW FMS sub-TLV" depicted below is carried as a sub-TLV of the "MPLS-TP PW OAM Configuration TLV". 0 1 2 3 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Fault mgmt Type (4) | Length (8) | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |A|D|L| Reserved (set to all 0s) |E| PHB | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Refresh Timer | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ MPLS-TP PW FMS sub-TLV Type: The "MPLS-TP PW FMS sub-TLV" type is 3. Length: indicates the length of the parameters in octets (8). Signal Flags: are used to enable the following signals: o A: Alarm Indication Signal (AIS) as described in [RFC6427] o D: Link Down Indication (LDI) as described in [RFC6427] o L: Locked Report (LKR) as described in [RFC6427] o Remaining bits: Reserved for future specification and set to 0. Configuration Flags: o E: used to enable/disable explicitly clearing faults o PHB: identifies the per-hop behavior of packets with fault management information Refresh Timer: indicates the refresh timer (in microseconds) of fault indication messages. If the T-PE receiving the Path message can not support such value, it can reply back with a higher interval. Zhang, et al. Expires December 26, 2015 [Page 18] Internet-Draft LDP Extensions for TP PW OAM June 2015 5. IANA Considerations 5.1. TLV IANA is requested to assign three new TLV types from the registry "TLV Type Name Space" in the "Label Distribution Protocol (LDP) Parameters" registry. Value TLV References ----- -------- ---------- TBD1 MPLS-TP PW OAM Administration TLV this document TBD2 MPLS-TP PW OAM Configuration TLV this document 5.1.1. MPLS-TP PW OAM Configuration Sub-TLV IANA is requested to create a registry of "MPLS-TP Pseudowire OAM Configuration Sub-TLV types". These are 16 bit values. Sub-TLV types 1 through 8 are specified in this document. Sub-TLV types 0 and 65535 are reserved. Sub-TLV 9 through 65534 are to be assigned by IANA, using the "Expert Review" policy defined in [RFC5226]. Value Sub-TLV References ----- -------- ---------- 1 BFD Configuration sub-TLV this document 2 Performance Monitoring sub-TLV this document 3 MPLS-TP PW FMS sub-TLV this document 5.1.1.1. BFD Configuration sub-TLVs IANA is requested to create a registry of "MPLS-TP Pseudowire OAM BFD Configuration Sub-TLV types". These are 16 bit values. Sub-TLV types 1 through 3 are specified in this document. Sub-TLV types 0 and 65535 are reserved. Sub-TLV 4 through 65534 are to be assigned by IANA, using the "Expert Review" policy defined in [RFC5226]. Value Sub-TLV References ----- -------- ---------- 1 Local Discriminator sub-TLV this document 2 Negotiation Timer Parameters sub-TLV this document 3 BFD Authentication sub-TLV this document 5.1.1.2. Performance Monitoring sub-TLVs IANA is requested to create a registry of "MPLS-TP Pseudowire OAM Performance Monitoring Sub-TLV types". These are 16 bit values. Sub-TLV types 1 through 2 are specified in this document. Sub-TLV types 0 and 65535 are reserved. Sub-TLV 3 through 65534 are to be Zhang, et al. Expires December 26, 2015 [Page 19] Internet-Draft LDP Extensions for TP PW OAM June 2015 assigned by IANA, using the "Expert Review" policy defined in [RFC5226]. Value Sub-TLV References ----- -------- ---------- 1 MPLS-TP PW PM Loss TLV this document 2 MPLS-TP PW PM Delay TLV this document 5.2. OAM Configuration Error Code IANA is requested to assign the following LDP status codes from the registry "STATUS CODE NAME SPACE" in the "Label Distribution Protocol (LDP) Parameters" registry. Range/Value E Description ----------- ----- ------------------- TBD3 0 "MIP Configuration Failure" TBD4 0 "Rejected MPLS-TP PW OAM Configuration TLV" TBD5 0 "Fail to Establish and Congfigure OAM Entities" TBD6 0 "Unsupported OAM Version" TBD7 0 "Unsupported BFD TX Echo rate interval" 6. Security Considerations Security considerations relating to LDP are described in section 5 of [RFC5036] and section 11 of [RFC5561]. Security considerations relating to use of LDP in setting up PWs is described in section 8 of [RFC4447]. This document defines new TLV/sub-TLV types, and OAM configuration procedures intended for use with MPLS-TP, which do not raise any additional security issues. 7. Acknowledgement The authors would like to thank Andrew Malis, Greg Mirsky, Luca Martini, Matthew Bocci, Thomas Nadeau for their valuable comments and discussions, especially would like to thank Eric Gray for his review of this document. 8. References 8.1. Normative references [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate Requirement Levels", BCP 14, RFC 2119, March 1997. Zhang, et al. Expires December 26, 2015 [Page 20] Internet-Draft LDP Extensions for TP PW OAM June 2015 [RFC4447] Martini, L., Rosen, E., El-Aawar, N., Smith, T., and G. Heron, "Pseudowire Setup and Maintenance Using the Label Distribution Protocol (LDP)", RFC 4447, April 2006. [RFC5036] Andersson, L., Minei, I., and B. Thomas, "LDP Specification", RFC 5036, October 2007. [RFC5561] Thomas, B., Raza, K., Aggarwal, S., Aggarwal, R., and JL. Le Roux, "LDP Capabilities", RFC 5561, July 2009. 8.2. Informative References [RFC3985] Bryant, S. and P. Pate, "Pseudo Wire Emulation Edge-to- Edge (PWE3) Architecture", RFC 3985, March 2005. [RFC5226] Narten, T. and H. Alvestrand, "Guidelines for Writing an IANA Considerations Section in RFCs", BCP 26, RFC 5226, May 2008. [RFC5654] Niven-Jenkins, B., Brungard, D., Betts, M., Sprecher, N., and S. Ueno, "Requirements of an MPLS Transport Profile", RFC 5654, September 2009. [RFC5659] Bocci, M. and S. Bryant, "An Architecture for Multi- Segment Pseudowire Emulation Edge-to-Edge", RFC 5659, October 2009. [RFC5860] Vigoureux, M., Ward, D., and M. Betts, "Requirements for Operations, Administration, and Maintenance (OAM) in MPLS Transport Networks", RFC 5860, May 2010. [RFC5880] Katz, D. and D. Ward, "Bidirectional Forwarding Detection (BFD)", RFC 5880, June 2010. [RFC6371] Busi, I. and D. Allan, "Operations, Administration, and Maintenance Framework for MPLS-Based Transport Networks", RFC 6371, September 2011. [RFC6374] Frost, D. and S. Bryant, "Packet Loss and Delay Measurement for MPLS Networks", RFC 6374, September 2011. [RFC6427] Swallow, G., Fulignoli, A., Vigoureux, M., Boutros, S., and D. Ward, "MPLS Fault Management Operations, Administration, and Maintenance (OAM)", RFC 6427, November 2011. Zhang, et al. Expires December 26, 2015 [Page 21] Internet-Draft LDP Extensions for TP PW OAM June 2015 Authors' Addresses Fei Zhang (editor) Huawei Email: zhangfei7@huawei.com Bo Wu (editor) ZTE Corporation Email: wu.bo@zte.com.cn Elisa Bellagamba (editor) Ericsson Farogatan 6 Kista, 164 40 Sweden Phone: +46 761440785 Email: elisa.bellagamba@ericsson.com Mach(Guoyi) Chen (editor) Huawei Email: mach.chen@huawei.com Zhang, et al. Expires December 26, 2015 [Page 22]