Network Working Group F. Zhang, Ed. Internet-Draft Huawei Intended status: Standards Track B. Wu, Ed. Expires: July 3, 2015 ZTE Corporation E. Bellagamba, Ed. Ericsson M. Chen, Ed. Huawei December 30, 2014 Label Distribution Protocol Extensions for Proactive Operations, Administration and Maintenance Configuration of Dynamic MPLS Transport Profile PseudoWire draft-ietf-pals-mpls-tp-oam-config-00 Abstract This document specifies extensions to the Label Distribution Protocol (LDP) to configure and control proactive Operations, Administration and Maintenance (OAM) functions, which are suitable for dynamic Single-Segment PseudoWire (SS-PW) and Multi-Segment PseudoWire (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 July 3, 2015. Copyright Notice Copyright (c) 2014 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 Zhang, et al. Expires July 3, 2015 [Page 1] Internet-Draft PW OAM Config December 2014 (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 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 Overview . . . . . . . . . . . . 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 . . . . . . . . . . . . 6 3.1.3. Deleting OAM Entities . . . . . . . . . . . . . . . . 7 3.2. OAM Configuration for SS-PW . . . . . . . . . . . . . . . 8 4. LDP Extensions . . . . . . . . . . . . . . . . . . . . . . . 8 4.1. MPLS-TP PW OAM Capability TLV . . . . . . . . . . . . . . 8 4.1.1. Backward Compatibility . . . . . . . . . . . . . . . 9 4.2. MPLS-TP PW OAM Administration TLV . . . . . . . . . . . . 9 4.3. MPLS-TP PW OAM Configuration TLV . . . . . . . . . . . . 10 4.3.1. BFD Configuration sub-TLV . . . . . . . . . . . . . . 11 4.3.1.1. Local Discriminator sub-TLV . . . . . . . . . . . 13 4.3.1.2. Negotiation Timer Parameters sub-TLV . . . . . . 13 4.3.1.3. BFD Authentication sub-TLV . . . . . . . . . . . 15 4.3.2. Performance Monitoring sub-TLV . . . . . . . . . . . 15 4.3.2.1. MPLS-TP PW PM Loss TLV . . . . . . . . . . . . . 16 4.3.2.2. MPLS-TP PW PM Delay TLV . . . . . . . . . . . . . 18 4.3.3. MPLS-TP PW FMS TLV . . . . . . . . . . . . . . . . . 19 5. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 20 5.1. TLV . . . . . . . . . . . . . . . . . . . . . . . . . . . 20 5.1.1. MPLS-TP PW OAM Configuration Sub-TLV . . . . . . . . 20 5.2. OAM Configuration Error Code . . . . . . . . . . . . . . 20 6. Security Considerations . . . . . . . . . . . . . . . . . . . 21 7. Acknowledgement . . . . . . . . . . . . . . . . . . . . . . . 21 8. References . . . . . . . . . . . . . . . . . . . . . . . . . 21 8.1. Normative references . . . . . . . . . . . . . . . . . . 21 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) Zhang, et al. Expires July 3, 2015 [Page 2] Internet-Draft PW OAM Config December 2014 describes a profile of MPLS that enables operational models typical in transport networks, while providing additional Operations, Administration and Maintenance (OAM), survivability and other maintenance functions not previously supported by IP/MPLS. 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 such as 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, 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 (Requirement 51)[RFC5654]. This document defines extensions to the LDP protocol to negotiate PW OAM capabilities, configure and bootstrap proactive PW OAM functions, which are suitable for Point to Point (P2P) SS-PW and MS-PW. The extensions to Point to Multi-Point (P2MP) PW will be studied in the future. 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 Zhang, et al. Expires July 3, 2015 [Page 3] Internet-Draft PW OAM Config December 2014 FEC: Forwarding Equivalence Class 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 Zhang, et al. Expires July 3, 2015 [Page 4] Internet-Draft PW OAM Config December 2014 SPME: Sub-Path Maintenance Entity 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 Overview When OAM functions are required for PWs, before starting to configure and enable the OAM functions, the PEs SHOULD negotiate the OAM capability when the PWs are first set up, hence to know what OAM functions the PEs can support. To achieve this, a new LDP TLV, MPLS- TP PW OAM Capability TLV is defined (Section 4.1). It is included in the LDP Initialization message and used to carry the MPLS-TP PW OAM capabilities that a PE supports. If a PE does not receive any MPLS- TP PW OAM TLV from the remote PE, it SHOULD NOT send the MPLS-TP PW OAM configuration information to the PE and try to configure and enable related OAM functions. Section 3.1 describes the general OAM configuration procedures. For SS-PW and MS-PW, the OAM configuration procedures are mostly identical. One exception is that SS-PW does not need to configure the MIP function. Section 3.2 highlights the differences between the two. 3.1. OAM Configuration for MS-PW 3.1.1. Establishment of OAM Entities and Functions Assuming there is one PW that needs to be setup between T-PE1 and T-PE2, across S-PE1 and S-PE2. 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 OAM Configuration Scheme Zhang, et al. Expires July 3, 2015 [Page 5] Internet-Draft PW OAM Config December 2014 Fist of all, T-PE1 MUST setup the OAM sink function to be prepared to receive OAM messages and MUST suppress any OAM alarms (e.g., due to missing or unidentified OAM messages). The Mapping message MUST be sent with the "OAM Alarms Enabled" cleared and "OAM MIP Entities desired" set in the MPLS-TP PW OAM Administration TLV. When the Mapping message arrives at the downstream S-PEs, such as S-PE1 and S-PE2, they MUST establish and configure MIP entities according to the "I" flag in the MPLS-TP PW OAM Administration TLV. If failed, a Notification message SHOULD be sent, with a Status Code set to "MIP Configuration Failure". If OAM entities are established successfully, the middle points (S-PE1 and S-PE2) MUST forward the Mapping message downstream, the endpoint (T-PE2) MUST set the OAM source function and MUST be prepared to send OAM messages. The same rules are applied to the reverse direction (from T-PE2 to T-PE1), that is to say, T-PE2 needs to setup the OAM sink function to be prepared to receive OAM messages and MUST suppress any OAM alarms (e.g., due to missing or unidentified OAM messages). The Mapping message MUST be sent with the "OAM Alarms Enabled" cleared, "OAM MIP Entities desired" set in the MPLS-TP PW OAM Administration TLV. When T-PE1 receives the Mapping message, it completes any pending OAM configuration and enables the OAM source function to send OAM messages. After this, OAM entities are established and configured for the PW and OAM messages MAY already be exchanged, and OAM alarms can now be enabled. The T-PE nodes (T-PE1 and T-PE2), while still keeping OAM alarms disabled send a Notification message with "OAM Alarms Enabled" PW status flag set, and enable the OAM alarms after processing the Notification message. At this point, data-plane OAM is fully functional, and the MPLS-TP OAM PW configuration TLV MAY be omitted in subsequent Notification messages The PW MAY be setup with OAM entities right away with the first signalling, as described above, but a PW MAY be signalled and established without OAM configuration first, and OAM entities may be added later. This can be done by sending a Notification message with the related configuration parameters subsequently. 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 do so the T-PE nodes need to send a Notification message with the updated parameters. OAM parameters that influence the content and timing of OAM messages and identify the way OAM defects and alarms are derived and generated. Hence, to avoid spurious alarms, Zhang, et al. Expires July 3, 2015 [Page 6] Internet-Draft PW OAM Config December 2014 it is important that both sides, OAM sink and source, are updated in a synchronized way. Firstly, the alarms of the OAM sink function should be suppressed and only then should expected OAM parameters 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 Notification message with "OAM Alarms Enabled" 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 after the updated Notification message is sent. The receiver (T-PE2) MUST firstly disable all OAM alarms, then update the OAM parameters according to the information in the Notification message and reply with a Notification 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 Notification 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 Notification 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 Notification 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 Notification messages exchanges with "OAM Alarms Enabled" flag set are needed to enable OAM alarms again. 3.1.3. Deleting OAM Entities In some cases it may be useful to remove some or all OAM entities and functions from one PW without actually tearing down the connection. To avoid any spurious alarm, the following procedure should be followed: The T-PE nodes disable OAM alarms and SHOULD send Notification message to each other with "OAM Alarms Enabled" cleared but unchanged OAM configuration and without the MPLS-TP PW OAM Configuration TLV. After that, T-PE1 (T-PE2) SHOULD delete OAM source functions, then send a Notification message with "OAM MIP Entities desired" cleared. While T-PE2 (T-PE1) deletes OAM sink function, S-PE1 and S-PE2 delete MIP configuration when they receive the Notification message with "OAM MIP Entities desired" cleared. Zhang, et al. Expires July 3, 2015 [Page 7] Internet-Draft PW OAM Config December 2014 Alternatively, if only some OAM functions need to be removed, the T-PE node sends the Notification message with the updated OAM Configuration TLV. Changes between the contents of the previously signalled OAM Configuration TLV and the currently received TLV represent which functions SHOULD be removed/added. 3.2. OAM Configuration for SS-PW Assuming there is one PW that needs to be setup between T-PE1 and T-PE2. If the receiving PE (T-PE2) have initiated the MPLS-TP PW OAM configuration request to the other PE (T-PE1), it MUST compare its AII against T-PE1's. If it is numerically lower, will reply a Notification message with the updated "MPLS-TP PW OAM Configuration TLV", and the Status Code set to "Wrong MPLS-TP PW OAM Configuration TLV". On the other hand, if the T-PE2's AII is numerically higher than T-PE1's, it MUST reply a Notification message with Status Code set to "Rejected MPLS-TP PW OAM Configuration TLV". 4. LDP Extensions Below, LDP extensions to configure proactive MPLS-TP PW OAM functions are defined. 4.1. MPLS-TP PW OAM Capability TLV A new Capability Parameter TLV called the MPLS-TP PW OAM Capability TLV is defined, and the format 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 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |1|0| Type (TBD) | Length (= 4) | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |S| Reserved | Capability Data |F|D|L|V|C| +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ MPLS-TP PW OAM Capability TLV The value of the U-bit for the MPLS-TP PW OAM Capability TLV MUST be set to 1 so that a receiver MUST silently ignore this TLV if unknown to it, and continue processing the rest of the message[RFC5036]. Currently defined specific OAM Capability Flags in the "Capability Data" field from right to left are: Zhang, et al. Expires July 3, 2015 [Page 8] Internet-Draft PW OAM Config December 2014 One bit "C" (31, IANA to assign) CC mode supported One bit "V" (30, IANA to assign) CV mode supported One bit "L" (29, IANA to assign) PM Loss supported One bit "D" (28, IANA to assign) PM Delay supported One bit "F" (27, IANA to assign) FMS supported Bits 8-26: This field MUST be set to zero on transmission and MUST be ignored on receipt. The above bits can be set individually to indicate more than one kind of OAM capabilities at once, and the other reserved bits MUST be set to zero on transmission and MUST be ignored on receipt. Moreover, if CV flag is set, the CC flag MUST be set at the same time. The MPLS-TP PW OAM Capability TLV MAY be included by a PE in an Initialization message to signal its peer that it supports the MPLS- TP PW OAM Capability. If the remote peer does not support the MPLS- TP PW OAM Capability TLV or the Initialization message sent by the remote peer does not include the MPLS-TP PW OAM Capability TLV, the resulting negotiation does not support MPLS-TP PW OAM capability. If instead the negotiation supports the MPLS-TP PW OAM capability, then the subsequent LDP Mapping message will carry the information of the MPLS-TP PW OAM configuration. 4.1.1. Backward Compatibility If both the two T-PEs can recognize the MPLS-TP PW OAM Capability TLV,and CC or CV mode is supported, the BFD configuration procedure described in this document is adopted. Otherwise, if at least one of the two T-PEs do not support the CC or CV mode, the old VCCV BFD [RFC5885] will be performed. In this situation, the procedure described in [RFC5885] MUST be followed: the C and V flags of MPLS-TP PW OAM Configuration TLV MUST NOT be set and the BFD Configuration sub-TLV MUST NOT be carried as a sub-TLV of MPLS-TP PW OAM Configuration TLV also. The described behavior ensures full compatibility with the existing implementations. 4.2. MPLS-TP PW OAM Administration TLV The format of the MPLS-TP PW OAM Administration TLV is as follows: Zhang, et al. Expires July 3, 2015 [Page 9] Internet-Draft PW OAM Config December 2014 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 (TBD) | Length | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |I|A| Reserved | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ MPLS-TP PW OAM Administration TLV One bit "I" (0, IANA to assign): "OAM MIP Entities Desired" is allocated. If the "OAM MIP entities desired" bit is set, it is indicating that the establishment of OAM MIP entities is required at every transit node of the signalled PW. If the establishment of a MIP is not supported, a Notification message MUST be sent with Status Code set to "MIP Configuration Failure". One bit "A" (1, IANA to assign): "OAM Alarms Enabled" is allocated. If the "OAM Alarms Enabled" bit is set, it is indicating that the T-PE needs to enable OAM alarms. Reserved (2-31 bits): This field MUST be set to zero on transmission and MUST be ignored on receipt. 4.3. MPLS-TP PW OAM Configuration TLV The "MPLS-TP PW OAM Configuration TLV" is depicted in the following figure. It may be carried in the Mapping and Notification messages, just following the PW Status 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 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |0|0| Type (TBD) | Length | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |C|V|L|D|F| 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 as well as OAM function specific sub-TLVs with configuration parameters for the particular functions. Zhang, et al. Expires July 3, 2015 [Page 10] Internet-Draft PW OAM Config December 2014 Type: indicates a new type: the MPLS-TP PW OAM Configuration TLV (IANA to assign). Length: the length of the OAM Function Flags field including the total length of the sub-TLVs in octets. OAM Function Flags: a bitmap numbered from left to right as shown in the figure. These flags are defined in this document: OAM Function Flag bit# Description --------------------- --------------------------- 0 (C) Continuity Check (CC) 1 (V) Connectivity Verification (CV) 2 (L) Performance Monitoring/Loss (PM/Loss) 3 (D) Performance Monitoring/Delay (PM/Delay) 4 (F) Fault Management Signals (FMS) 5-31 Reserved (set all to 0s) Sub-TLVs corresponding to the different flags are as follows. o "BFD Configuration sub-TLV", which 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. o "Performance Monitoring sub-TLV", which MUST be included if the PM/Loss OAM Function flag is set. o "MPLS-TP PW FMS sub-TLV", which MAY be included if the FMS OAM Function flag is set. If the "MPLS-TP PW FMS sub-TLV" is not included, default configuration values are used. 4.3.1. 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. Zhang, et al. Expires July 3, 2015 [Page 11] Internet-Draft PW OAM Config December 2014 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 Conf. Type (1) (IANA) | Length | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |Vers.| PHB |N|S|I|G|U|A| Reserved (set to all 0s) | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | | ~ sub TLVs ~ | | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ BFD Configuration sub-TLV Type: indicates a new type, the "BFD Configuration sub-TLV" (IANA to define, suggested value 1). Length: indicates the length of the TLV including sub-TLVs but excluding the Type and Length field, in octets. Version: 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). 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. Zhang, et al. Expires July 3, 2015 [Page 12] Internet-Draft PW OAM Config December 2014 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. 4.3.1.1. 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) (IANA) | Length (4) | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Local Discriminator | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ Local Discriminator sub-TLV Type: indicates a new type, the "Local Discriminator sub-TLV" (IANA to define, suggested value 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. 4.3.1.2. 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. Zhang, et al. Expires July 3, 2015 [Page 13] Internet-Draft PW OAM Config December 2014 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) (IANA) | Length (16) | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Acceptable Min. Asynchronous TX interval | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Acceptable Min. Asynchronous RX interval | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Required Echo TX Interval | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ Negotiation Timer Parameters sub-TLV Type: indicates a new type, the "Negotiation Timer Parameters sub- TLV" (IANA to define, suggested value 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". 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 Zhang, et al. Expires July 3, 2015 [Page 14] Internet-Draft PW OAM Config December 2014 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. 4.3.1.3. 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) (IANA) | Length = 8 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Auth Type | Auth Key ID | Reserved (0s) | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ BFD Authentication sub-TLV Type: indicates a new type, the "BFD Authentication sub-TLV" (IANA to define, suggested value 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. 4.3.2. Performance Monitoring sub-TLV If the "MPLS-TP PW OAM Configuration TLV" has either the L (Loss), D (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, "MPLS-TP PW PM Delay sub-TLV" MAY be included: o "MPLS-PW PM Loss sub-TLV" if the L flag is set in the "MPLS-TP PW OAM Configuration TLV"; Zhang, et al. Expires July 3, 2015 [Page 15] Internet-Draft PW OAM Config December 2014 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 (IANA)| Length | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |D|L|J|Y|K|C| Reserved (set to all 0s) | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | | ~ sub-TLVs ~ | | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ Performance Monitoring sub-TLV 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) 4.3.2.1. 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". Zhang, et al. Expires July 3, 2015 [Page 16] Internet-Draft PW OAM Config December 2014 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 (1) (IANA) | Length | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | OTF |T|B| RESERVED | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Measurement Interval | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Test Interval | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Loss Threshold | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ MPLS-TP PW PM Loss sub-TLV Type: indicates a new type, the "MPLS-TP PW PM Loss sub-TLV" (IANA to define, suggested value 1). 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). Loss Threshold: the threshold value of lost packets over which protections MUST be triggered. By default it is set to (TBD). Zhang, et al. Expires July 3, 2015 [Page 17] Internet-Draft PW OAM Config December 2014 4.3.2.2. 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 (2) (IANA) | Length | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | OTF |T|B| RESERVED | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Measurement Interval | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Test Interval | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Delay Threshold | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ MPLS-TP PW PM Delay sub-TLV Type: indicates a new type, the "MPLS-TP PW PM Delay sub-TLV" (IANA to define, suggested value 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). Zhang, et al. Expires July 3, 2015 [Page 18] Internet-Draft PW OAM Config December 2014 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). 4.3.3. MPLS-TP PW FMS 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) (IANA) | Length (8) | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |A|D|L| Reserved (set to all 0s) |E| PHB | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Refresh Timer | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ MPLS-TP PW FMS sub-TLV Type: indicates a new type, the "MPLS-TP PW FMS sub-TLV" (IANA to define, suggested value 4). 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 July 3, 2015 [Page 19] Internet-Draft PW OAM Config December 2014 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 Capability TLV this document TBD2 MPLS-TP PW OAM Administration TLV this document TBD3 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 RFC2434. 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 4 Local Discriminator sub-TLV this document 5 Negotiation Timer Parameters sub-TLV this document 6 BFD Authentication sub-TLV this document 7 MPLS-TP PW PM Loss sub-TLV this document 8 MPLS-TP PW PM Loss sub-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 TBD4 0 "MIP Configuration Failure" TBD5 0 "Rejected MPLS-TP PW OAM Configuration TLV" TBD6 0 "Wrong MPLS-TP PW OAM Configuration TLV" TBD7 0 "Unsupported OAM Version" TBD8 0 "Unsupported BFD TX Echo rate interval" Zhang, et al. Expires July 3, 2015 [Page 20] Internet-Draft PW OAM Config December 2014 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. [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. [RFC6073] Martini, L., Metz, C., Nadeau, T., Bocci, M., and M. Aissaoui, "Segmented Pseudowire", RFC 6073, January 2011. 8.2. Informative References [RFC2434] Narten, T. and H. Alvestrand, "Guidelines for Writing an IANA Considerations Section in RFCs", BCP 26, RFC 2434, October 1998. [RFC3985] Bryant, S. and P. Pate, "Pseudo Wire Emulation Edge-to- Edge (PWE3) Architecture", RFC 3985, March 2005. Zhang, et al. Expires July 3, 2015 [Page 21] Internet-Draft PW OAM Config December 2014 [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. [RFC5885] Nadeau, T. and C. Pignataro, "Bidirectional Forwarding Detection (BFD) for the Pseudowire Virtual Circuit Connectivity Verification (VCCV)", RFC 5885, 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. [RFC6478] Martini, L., Swallow, G., Heron, G., and M. Bocci, "Pseudowire Status for Static Pseudowires", RFC 6478, May 2012. Authors' Addresses Fei Zhang (editor) Huawei Email: zhangfei7@huawei.com Bo Wu (editor) ZTE Corporation Email: wu.bo@zte.com.cn Zhang, et al. Expires July 3, 2015 [Page 22] Internet-Draft PW OAM Config December 2014 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 July 3, 2015 [Page 23]