MPLS Working Group                                    E. Bellagamba, Ed.
Internet-Draft                                              L. Andersson
Intended status: Standards Track                                Ericsson
Expires: January 12, 2012                             P. Skoldstrom, Ed.
                                                                Acreo AB
                                                                 D. Ward
                                                                J. Drake
                                                                 Juniper
                                                           July 11, 2011


Configuration of Pro-Active Operations,  Administration, and Maintenance
   (OAM) Functions for MPLS-based Transport Networks using  LSP Ping
              draft-ietf-mpls-lsp-ping-mpls-tp-oam-conf-02

Abstract

   This specification describes the configuration of pro-active MPLS-TP
   Operations, Administration, and Maintenance (OAM) Functions for a
   given LSP using a set of TLVs that are carried by the LSP Ping
   protocol

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

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 January 12, 2012.

Copyright Notice

   Copyright (c) 2011 IETF Trust and the persons identified as the



Bellagamba, et al.      Expires January 12, 2012                [Page 1]


Internet-Draft       Extensions for MPLS-TP OAM Conf           July 2011


   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
   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 . . . . . . . . . . . . . . . . . . . . . . . . .  3
     1.1.  Requirements Language  . . . . . . . . . . . . . . . . . .  4
   2.  Overview of MPLS OAM for Transport Applications  . . . . . . .  4
   3.  Theory of Operations . . . . . . . . . . . . . . . . . . . . .  5
     3.1.  MPLS OAM Configuration Operation Overview  . . . . . . . .  5
       3.1.1.  Configuration of BFD sessions  . . . . . . . . . . . .  5
       3.1.2.  Configuration of Performance Monitoring  . . . . . . .  6
       3.1.3.  Configuration of Measurements and FMS  . . . . . . . .  6
     3.2.  OAM Functions TLV  . . . . . . . . . . . . . . . . . . . .  6
       3.2.1.  BFD Configuration sub-TLV  . . . . . . . . . . . . . .  8
         3.2.1.1.  Local Discriminator sub-TLV  . . . . . . . . . . . 10
         3.2.1.2.  Negotiation Timer Parameters sub-TLV . . . . . . . 10
         3.2.1.3.  BFD Authentication sub-TLV . . . . . . . . . . . . 11
       3.2.2.  MPLS OAM Source MEP-ID sub-TLV . . . . . . . . . . . . 12
       3.2.3.  Performance Monitoring sub-TLV . . . . . . . . . . . . 13
         3.2.3.1.  MPLS OAM PM Loss sub-TLV . . . . . . . . . . . . . 14
         3.2.3.2.  MPLS OAM PM Delay sub-TLV  . . . . . . . . . . . . 15
       3.2.4.  MPLS OAM FMS sub-TLV . . . . . . . . . . . . . . . . . 16
     3.3.  IANA Considerations  . . . . . . . . . . . . . . . . . . . 17
   4.  OAM configuration errors . . . . . . . . . . . . . . . . . . . 17
   5.  Security Considerations  . . . . . . . . . . . . . . . . . . . 18
   6.  References . . . . . . . . . . . . . . . . . . . . . . . . . . 18
     6.1.  Normative References . . . . . . . . . . . . . . . . . . . 18
     6.2.  Informative References . . . . . . . . . . . . . . . . . . 19
   Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 20











Bellagamba, et al.      Expires January 12, 2012                [Page 2]


Internet-Draft       Extensions for MPLS-TP OAM Conf           July 2011


1.  Introduction

   This document describes the configuration of pro-active MPLS-TP
   Operations, Administration, and Maintenance (OAM) Functions for a
   given LSP using TLVs carried in LSP Ping [BFD-Ping].  In particular
   it specifies the mechanisms necessary to establish MPLS-TP OAM
   entities for monitoring and performing measurements on an LSP, as
   well as defining information elements and procedures to configure
   pro-active MPLS OAM functions.  Initialization and control of on-
   demand MPLS OAM functions are expected to be carried out by directly
   accessing network nodes via a management interface; hence
   configuration and control of on-demand OAM functions are out-of-scope
   for this document.

   The Transport Profile of MPLS must, by definition [RFC5654], be
   capable of operating without a control plane.  Therefore there are
   three options for configuring MPLS-TP OAM, without a control plane by
   either using an NMS or LSP Ping, or with a control plane using GMPLS
   (specifically RSVP-TE) .

   Pro-active MPLS OAM is performed by three different protocols,
   Bidirectional Forwarding Detection (BFD) [RFC5880] for Continuity
   Check/Connectivity Verification, the delay measurement protocol (DM)
   [MPLS-PM] for delay and delay variation (jitter) measurements, and
   the loss measurement protocol (LM) [MPLS-PM] for packet loss and
   throughput measurements.  Additionally there is a number of Fault
   Management Signals that can be configured.

   BFD is a protocol that provides low-overhead, fast detection of
   failures in the path between two forwarding engines, including the
   interfaces, data link(s), and to the extent possible the forwarding
   engines themselves.  BFD can be used to track the liveliness and
   detect data plane failures of MPLS-TP point-to-point and might also
   be extended to support point-to-multipoint connections.

   The delay and loss measurements protocols [MPLS-PM] use a simple
   query/response model for performing bidirectional measurements that
   allows the originating node to measure packet loss and delay in both
   directions.  By timestamping and/or writing current packet counters
   to the measurement packets at four times (Tx and Rx in both
   directions) current delays and packet losses can be calculated.  By
   performing successive delay measurements the delay variation (jitter)
   can be calculated.  Current throughput can be calculated from the
   packet loss measurements by dividing the number of packets sent/
   received with the time it took to perform the measurement, given by
   the timestamp in LM header.  Combined with a packet generator the
   throughput measurement can be used to measure the maximum capacity of
   a particular LSP.



Bellagamba, et al.      Expires January 12, 2012                [Page 3]


Internet-Draft       Extensions for MPLS-TP OAM Conf           July 2011


   MPLS Transport Profile (MPLS-TP) describes a profile of MPLS that
   enables operational models typical in transport networks, while
   providing additional OAM, survivability and other maintenance
   functions not currently supported by MPLS.  [RFC5860] defines the
   requirements for the OAM functionality of MPLS-TP.

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

1.1.  Requirements Language

   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 RFC 2119 [RFC2119].


2.  Overview of MPLS OAM for Transport Applications

   [MPLS-TP-OAM-FWK] describes how MPLS OAM mechanisms are operated to
   meet transport requirements outlined in [RFC5860].

   [BFD-CCCV] specifies two BFD operation modes: 1) "CC mode", which
   uses periodic BFD message exchanges with symmetric timer settings,
   supporting Continuity Check, 2) "CV/CC mode" which sends unique
   maintenance entity identifiers in the periodic BFD messages
   supporting Connectivity Verification as well as Continuity Check.

   [MPLS-PM] specifies mechanisms for performance monitoring of LSPs, in
   particular it specifies loss and delay measurement OAM functions.

   [MPLS-FMS] specifies fault management signals with which a server LSP
   can notify client LSPs about various fault conditions to suppress
   alarms or to be used as triggers for actions in the client LSPs.  The
   following signals are defined: Alarm Indication Signal (AIS), Link
   Down Indication (LDI) and Locked Report (LKR).  To indicate client
   faults associated with the attachment circuits Client Signal Failure
   Indication (CSF) can be used.  CSF is described in [MPLS-TP-OAM-FWK]
   and in the context of this document is for further study.

   [MPLS-TP-OAM-FWK] describes the mapping of fault conditions to
   consequent actions.  Some of these mappings may be configured by the
   operator, depending on the application of the LSP.  The following
   defects are identified: Loss Of Continuity (LOC), Misconnectivity,
   MEP Misconfiguration and Period Misconfiguration.  Out of these
   defect conditions, the following consequent actions may be



Bellagamba, et al.      Expires January 12, 2012                [Page 4]


Internet-Draft       Extensions for MPLS-TP OAM Conf           July 2011


   configurable: 1) whether or not the LOC defect should result in
   blocking the outgoing data traffic; 2) whether or not the "Period
   Misconfiguration defect" should result in a signal fail condition.


3.  Theory of Operations

3.1.  MPLS OAM Configuration Operation Overview

   LSP Ping, or alternatively RSVP-TE [RSVP-TE CONF], can be used to
   simply enable the different OAM functions, by setting the
   corresponding flags in the "OAM Functions TLV".  Additionally one may
   include sub-TLVs for the different OAM functions in order to specify
   different parameters in detail.

3.1.1.  Configuration of BFD sessions

   For this specification, BFD MUST be run in either one of the two
   modes:

      - Asynchronous mode, where both sides should be in active mode.

      - Unidirectional mode

   In the simplest scenario LSP Ping, or alternatively RSVP-TE [RSVP-TE
   CONF], is used only to bootstrap a BFD session for an LSP, without
   any timer negotiation.

   Timer negotiation can be performed either in subsequent BFD control
   messages (in this case the operation is similar to LSP Ping based
   bootstrapping described in [RFC5884]) or directly in the LSP ping
   configuration messages.

   When BFD Control packets are transported in the G-ACh they are not
   protected by any end-to-end checksum, only lower-layers are providing
   error detection/correction.  A single bit error, e.g. a flipped bit
   in the BFD State field could cause the receiving end to wrongly
   conclude that the link is down and in turn trigger protection
   switching.  To prevent this from happening the "BFD Configuration
   sub-TLV" has an Integrity flag that when set enables BFD
   Authentication using Keyed SHA1 with an empty key (all 0s) [RFC5880].
   This would make every BFD Control packet carry an SHA1 hash of itself
   that can be used to detect errors.

   If BFD Authentication using a pre-shared key / password is desired
   (i.e. actual authentication not only error detection) the "BFD
   Authentication sub-TLV" MUST be included in the "BFD Configuration
   sub-TLV".  The "BFD Authentication sub-TLV" is used to specify which



Bellagamba, et al.      Expires January 12, 2012                [Page 5]


Internet-Draft       Extensions for MPLS-TP OAM Conf           July 2011


   authentication method that should be used and which pre-shared key /
   password that should be used for this particular session.  How the
   key exchange is performed is out of scope of this document.

3.1.2.  Configuration of Performance Monitoring

   It is possible to configure Performance Monitoring functionalities
   such as Loss, Delay and Throuhput as described in [MPLS-PM].

   When configuring Performance monitoring functionalities it can be
   choosen either the default configuration (by only setting the
   respective flags in the "OAM functions TLV") or a customized
   configuration (by including the respective Loss and/or Delay sub-
   TLVs).

3.1.3.  Configuration of Measurements and FMS

   Additional OAM functions may be configured by setting the appropriate
   flags in the "OAM Functions TLV", these include Performance
   Measurements (packet loss, throughput, delay, and delay variation)
   and Fault Management Signal handling.

   By setting the PM Loss flag in the "OAM Functions TLV" and including
   the "MPLS OAM PM Loss sub-TLV" one can configure the measurement
   interval and loss threshold values for triggering protection.

   Delay measurements are configured by setting PM Delay flag in the
   "OAM Functions TLV" and including the "MPLS OAM PM Loss sub-TLV" one
   can configure the measurement interval and the delay threshold values
   for triggering protection.

   To configure Fault Monitoring Signals and their refresh time the FMS
   flag in the "OAM Functions TLV" MUST be set and the "MPLS OAM FMS
   sub-TLV" included.

3.2.  OAM Functions TLV

   The "OAM Functions TLV" depicted below is carried as a TLV of the LSP
   Echo request/response messages.












Bellagamba, et al.      Expires January 12, 2012                [Page 6]


Internet-Draft       Extensions for MPLS-TP OAM Conf           July 2011


    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
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |  OAM Func. Type (16) (IANA)   |           Length              |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |C|V|L|D|F|           OAM Function Flags                        |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |                                                               |
   ~                           sub-TLVs                            ~
   |                                                               |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

   The "OAM Functions 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 function.

   Type: indicates a new type, the "OAM Functions TLV" (IANA to define,
   suggested value 16).

   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 (F)             Fault Management Signals (FMS)
            3 (L)             Performance Monitoring/Loss (PM/Loss)
            4 (D)             Performance Monitoring/Delay (PM/Delay)
            5 (T)             Throughput Measurement
            6-31              Reserved (set all to 0s)

   Sub-TLVs corresponding to the different flags are as follows:

      - "BFD Configuration sub-TLV", which MUST be included if the CC
      and/or the CV OAM Function flag is set.  This sub-TLV MUST carry a
      "BFD Local Discriminator sub-TLV" and a "Timer Negotiation
      Parameters sub-TLV" if the N flag is cleared.  "MPLS OAM Source
      MEP-ID sub-TLV" MUST also be included.  If the I flag is set, the
      "BFD Authentication sub-TLV" may be included.





Bellagamba, et al.      Expires January 12, 2012                [Page 7]


Internet-Draft       Extensions for MPLS-TP OAM Conf           July 2011


      - "MPLS OAM PM Loss sub-TLV" within the "Performance Monitoring
      sub-TLV", which MAY be included if the PM/Loss OAM Function flag
      is set.  If the "MPLS OAM PM Loss sub-TLV" is not included,
      default configuration values are used.  Such sub-TLV MAY also be
      included in case the Throughput function flag is set and there is
      the need to specify measurement interval different from the
      default ones.  In fact the throughput measurement make use of the
      same tool as the loss measurement, hence the same TLV is used.

      - "MPLS OAM PM Delay sub-TLV" within the "Performance Monitoring
      sub-TLV", which MAY be included if the PM/Delay OAM Function flag
      is set.  If the "MPLS OAM PM Delay sub-TLV" is not included,
      default configuration values are used.

      - "MPLS OAM FMS sub-TLV", which MAY be included if the FMS OAM
      Function flag is set.  If the "MPLS OAM FMS sub-TLV" is not
      included, default configuration values are used.

3.2.1.  BFD Configuration sub-TLV

   The "BFD Configuration sub-TLV" (depicted below) is defined for BFD
   OAM specific configuration parameters.  The "BFD Configuration sub-
   TLV" is carried as a sub-TLV of the "OAM Functions TLV".

   This TLV 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
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |  BFD Conf. Type (1) (IANA)    |           Length              |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |Vers.| PHB |N|S|I|G|U|B|   Reserved (set to all 0s)            |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |                                                               |
   ~                           sub TLVs                            ~
   |                                                               |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

   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 an error must be generated: "OAM



Bellagamba, et al.      Expires January 12, 2012                [Page 8]


Internet-Draft       Extensions for MPLS-TP OAM Conf           July 2011


   Problem/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.  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 UDP packets.  If both the G bit and U
   bit are set, configuration gives precedence to the G bit.

   Bidirectional (B): if set, it configures BFD in the Bidirectional
   mode.  If it is not set it configures BFD in unidirectional mode.  In
   the second case, the source node does not expect any Discriminator
   values back from the destination node.

   The "BFD Configuration sub-TLV" MUST include the following sub-TLVs
   in the LSP Echo request message:

      - "Local Discriminator sub-TLV";

      - "Negotiation Timer Parameters sub-TLV" if the N flag is cleared.

   The "BFD Configuration sub-TLV" MUST include the following sub-TLVs
   in the LSP Echo reply message:

      - "Local Discriminator sub-TLV;"

      - "Negotiation Timer Parameters sub-TLV" if:

         - the N and S flags are cleared

         - the N flag is cleared and the S flag is set and a timing
         interval larger than the one received needs to be used




Bellagamba, et al.      Expires January 12, 2012                [Page 9]


Internet-Draft       Extensions for MPLS-TP OAM Conf           July 2011


   Reserved: Reserved for future specification and set to 0.

3.2.1.1.  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.

   [Author's note: This should be aligned with RFC5884, exactly how to
   do that is under discussion. ]


    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                     |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

   Type: indicates a new type, the "Local Discriminator sub-TLV" (IANA
   to define, suggested value 1).

   Length: indicates the TLV total length in octets.

   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.

3.2.1.2.  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) (IANA)  |          Length (16)          |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |         Acceptable Min. Asynchronous TX interval              |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |         Acceptable Min. Asynchronous RX interval              |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |               Required Echo TX Interval                       |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

   Type: indicates a new type, the "Negotiation Timer Parameters sub-
   TLV" (IANA to define, suggested value 2).



Bellagamba, et al.      Expires January 12, 2012               [Page 10]


Internet-Draft       Extensions for MPLS-TP OAM Conf           July 2011


   Length: indicates the length of the parameters 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 LER initiating the
   signaling intends to both transmit and receive BFD periodic control
   packets.  If the receiving edge LSR 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 a edge LSR 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 edge LSRs can receive BFD periodic control packets.  In case
   this value is greater than the "Acceptable Min. Asynchronous TX
   interval" received from the other edge LSR, such edge LSR 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
   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 an error MUST be generated "Unsupported BFD TX
   Echo rate interval".  By default the value is set to 0.

3.2.1.3.  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.









Bellagamba, et al.      Expires January 12, 2012               [Page 11]


Internet-Draft       Extensions for MPLS-TP OAM Conf           July 2011


    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)         |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

   Type: indicates a new type, the "BFD Authentication sub-TLV" (IANA to
   define).

   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.

3.2.2.  MPLS OAM Source MEP-ID sub-TLV

   The "MPLS OAM Source MEP-ID sub-TLV" depicted below is carried as a
   sub-TLV of the "OAM Functions 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
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   | Source MEP-ID Type (4) (IANA) |        Length (8)             |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |                       Source Node ID                          |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |           Tunnel ID           |           LSP ID              |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

   Type: indicates a new type, the "MPLS OAM Source MEP-ID sub-TLV"
   (IANA to define, suggested value 3).

   Length: indicates the length of the parameters in octets (8).

   Source Node ID: 32-bit node identifier as defined in [MPLS-TP-
   IDENTIF].

   Tunnel ID: a 16-bit unsigned integer unique to the node as defined in
   [MPLS-TP-IDENTIF].



Bellagamba, et al.      Expires January 12, 2012               [Page 12]


Internet-Draft       Extensions for MPLS-TP OAM Conf           July 2011


   LSP ID: a 16-bit unsigned integer unique within the Tunnel_ID as
   defined in [MPLS-TP-IDENTIF].

3.2.3.  Performance Monitoring sub-TLV

   If the "OAM functions TLV" has either the L (Loss), D (Delay) or T
   (Throughput) flag set, the "Performance Monitoring sub-TLV" MUST be
   present.

   In case the vlues needs to be different than the default ones the
   "Performance Monitoring sub-TLV", "MPLS OAM PM Loss sub-TLV" MAY
   include the following sub-TLVs:

      - "MPLS OAM PM Loss sub-TLV" if the L flag is set in the "OAM
      functions TLV";

      - "MPLS OAM PM Delay sub-TLV" if the D flag is set in the "OAM
      functions TLV";

   The "Performance Monitoring sub-TLV" depicted below is carried as a
   sub-TLV of the "OAM Functions TLV".


   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                            ~
   |                                                               |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+


   Configuration Flags, for the specific function description please
   refer to [MPLS-PM]:

      - D: Delay inferred/direct (0=INFERRED, 1=DIRECT)

      - L: Loss inferred/direct (0=INFERRED, 1=DIRECT)

      - J: Delay variation/jitter (1=ACTIVE, 0=NOT ACTIVE)

      - Y: Dyadic (1=ACTIVE, 0=NOT ACTIVE)

      - K: Loopback (1=ACTIVE, 0=NOT ACTIVE)




Bellagamba, et al.      Expires January 12, 2012               [Page 13]


Internet-Draft       Extensions for MPLS-TP OAM Conf           July 2011


      - C: Combined (1=ACTIVE, 0=NOT ACTIVE)

3.2.3.1.  MPLS OAM PM Loss sub-TLV

   The "MPLS OAM PM Loss sub-TLV" depicted below is carried as a sub-TLV
   of the "Performance Monitoring sub-TLV".


   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                           |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+


   Type: indicates a new type, the "MPLS OAM PM Loss sub-TLV" (IANA to
   define, suggested value 1).

   Length: indicates the length of the parameters in octets (12).

   OTF: Origin Timestamp Format of the Origin Timestamp field described
   in [MPLS-PM].  By default it is set to IEEE 1588 version 1.

   Configuration Flags, please refer to [MPLS-PM] for further details:

      - 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.

      - 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
   Loss Measurement query messages MUST be sent on both directions.  If
   the edge LSR receiving the Path message can not support such value,
   it can reply back with a higher interval.  By default it is set to
   (TBD).



Bellagamba, et al.      Expires January 12, 2012               [Page 14]


Internet-Draft       Extensions for MPLS-TP OAM Conf           July 2011


   Test Interval: test messages interval as described in [MPLS-PM].  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).

3.2.3.2.  MPLS OAM PM Delay sub-TLV

   The "MPLS OAM PM Delay sub-TLV" depicted below is carried as a sub-
   TLV of the "OAM Functions TLV".


   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                          |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+


   Type: indicates a new type, the "MPLS OAM PM Loss sub-TLV" (IANA to
   define, suggested value 1).

   Length: indicates the length of the parameters in octets (12).

   OTF: Origin Timestamp Format of the Origin Timestamp field described
   in [MPLS-PM].  By default it is set to IEEE 1588 version 1.

   Configuration Flags, please refer to [MPLS-PM] for further details:

      - 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.

      - 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



Bellagamba, et al.      Expires January 12, 2012               [Page 15]


Internet-Draft       Extensions for MPLS-TP OAM Conf           July 2011


   Delay Measurement query messages MUST be sent on both directions.  If
   the edge LSR receiving the Path 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 [MPLS-PM].  By
   default it is set to (TBD).

   Delay Threshold: the threshold value of measured delay (in
   microseconds) over which protections MUST be triggered.  By default
   it is set to (TBD).

3.2.4.  MPLS OAM FMS sub-TLV

   The "MPLS OAM FMS sub-TLV" depicted below is carried as a sub-TLV of
   the "OAM Functions 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|C|                Reserved (set to all 0s)       |E| PHB |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |                      Refresh Timer                            |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

   Type: indicates a new type, the "MPLS OAM 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:

      - A: Alarm Indication Signal (AIS) as described in [MPLS-FMS]

      - D: Link Down Indication (LDI) as described in [MPLS-FMS]

      - L: Locked Report (LKR) as described in [MPLS-FMS]

      - C: Client Signal Failure (CSF) as described in [MPLS-CSF]

      - Remaining bits: Reserved for future specification and set to 0.

   Configuration Flags:





Bellagamba, et al.      Expires January 12, 2012               [Page 16]


Internet-Draft       Extensions for MPLS-TP OAM Conf           July 2011


      - E: used to enable/disable explicitly clearing faults

      - 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 edge LSR receiving the Path message can
   not support such value, it can reply back with a higher interval.

3.3.  IANA Considerations

   This document specifies the following new TLV types:

      - "OAM Functions" type: 16;

   sub-TLV types to be carried in the "OAM Functions TLV":

      - "BFD Configuration" type: 1;

      - "MPLS OAM PM Loss" type: 2;

      - "MPLS OAM PM Delay" type: 3;

      - "MPLS OAM FMS" type: 4.

   sub-TLV types to be carried in the "BFD Configuration sub-TLV":

      - "Local Discriminator" type: 1;

      - "Negotiation Timer Parameters" type: 2;

      - "MPLS OAM Source MEP-ID" type: 3.

      - "BFD Authentication" sub-TLV type: 4


4.  OAM configuration errors

   This document specifies additional Return Codes to LSP Ping:

      - "MPLS OAM Unsupported Functionality" (IANA to assign, suggested
      value 16);

      - "OAM Problem/Unsupported TX rate interval" (IANA to assign,
      suggested value 17.






Bellagamba, et al.      Expires January 12, 2012               [Page 17]


Internet-Draft       Extensions for MPLS-TP OAM Conf           July 2011


5.  Security Considerations

   The signaling of OAM related parameters and the automatic
   establishment of OAM entities introduces additional security
   considerations to those discussed in [RFC3473].  In particular, a
   network element could be overloaded if an attacker were to request
   high frequency liveliness monitoring of a large number of LSPs,
   targeting a single network element.

   Security aspects will be covered in more detailed in subsequent
   versions of this document.


6.  References

6.1.  Normative References

   [MPLS-FMS]
              Swallow, G., Fulignoli, A., Vigoureux, M., Boutros, S.,
              and D. Ward, "MPLS Fault Management OAM", 2009,
              <draft-ietf-mpls-tp-fault>.

   [MPLS-PM]  Bryant, S. and D. Frost, "Packet Loss and Delay
              Measurement for the MPLS Transport Profile", 2010,
              <draft-ietf-mpls-loss-delay>.

   [MPLS-PM-Profile]
              Bryant, S. and D. Frost, "A Packet Loss and Delay
              Measurement Profile for MPLS-based Transport Networks",
              2010, <draft-ietf-mpls-tp-loss-delay-profile>.

   [MPLS-TP-IDENTIF]
              Bocci, M., Swallow, G., and E. Gray, "MPLS-TP
              Identifiers", 2010, <draft-ietf-mpls-tp-identifiers>.

   [OAM-CONF-FWK]
              Takacs, A., Fedyk, D., and J. van He, "OAM Configuration
              Framework for GMPLS RSVP-TE", 2009,
              <draft-ietf-ccamp-oam-configuration-fwk>.

   [RFC2119]  Bradner, S., "Key words for use in RFCs to Indicate
              Requirement Levels", BCP 14, RFC 2119, March 1997.

   [RFC3471]  Berger, L., "Generalized Multi-Protocol Label Switching
              (GMPLS) Signaling Functional Description", RFC 3471,
              January 2003.

   [RFC5586]  Bocci, M., Vigoureux, M., and S. Bryant, "MPLS Generic



Bellagamba, et al.      Expires January 12, 2012               [Page 18]


Internet-Draft       Extensions for MPLS-TP OAM Conf           July 2011


              Associated Channel", RFC 5586, June 2009.

   [RFC5654]  Niven-Jenkins, B., Brungard, D., Betts, M., Sprecher, N.,
              and S. Ueno, "Requirements of an MPLS Transport Profile",
              RFC 5654, September 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.

   [RSVP-TE CONF]
              Bellagamba, E., Ward, D., Andersson, L., and P.
              Skoldstrom, "Configuration of pro-active MPLS-TP
              Operations, Administration, and Maintenance (OAM)
              Functions Using RSVP-TE", 2010,
              <draft-ietf-ccamp-rsvp-te-mpls-tp-oam-ext>.

6.2.  Informative References

   [BFD-CCCV]
              Allan, D., Swallow, G., and J. Drake, "Proactive
              Connectivity Verification, Continuity Check and Remote
              Defect indication for MPLS Transport Profile", 2010,
              <draft-ietf-mpls-tp-bfd-cc-cv-rdi-03>.

   [BFD-Ping]
              Bahadur, N., Aggarwal, R., Ward, D., Nadeau, T., Sprecher,
              N., and Y. Weingarten, "LSP Ping and BFD encapsulation
              over ACH", 2010,
              <draft-ietf-mpls-tp-lsp-ping-bfd-procedures-01>.

   [ETH-OAM]  Takacs, A., Gero, B., Fedyk, D., Mohan, D., and D. Long,
              "GMPLS RSVP-TE Extensions for Ethernet OAM", 2009,
              <draft-ietf-ccamp-rsvp-te-eth-oam-ext>.

   [MPLS-TP OAM Analysis]
              Sprecher, N., Weingarten, Y., and E. Bellagamba, "MPLS-TP
              OAM Analysis", 2011, <draft-ietf-mpls-tp-oam-analysis>.

   [MPLS-TP-OAM-FWK]
              Bocci, M. and D. Allan, "Operations, Administration and
              Maintenance Framework for MPLS-based Transport Networks",
              2010, <draft-ietf-mpls-tp-oam-framework>.

   [RFC3479]  Farrel, A., "Fault Tolerance for the Label Distribution



Bellagamba, et al.      Expires January 12, 2012               [Page 19]


Internet-Draft       Extensions for MPLS-TP OAM Conf           July 2011


              Protocol (LDP)", RFC 3479, February 2003.

   [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.

   [RFC5921]  Bocci, M., Bryant, S., Frost, D., Levrau, L., and L.
              Berger, "A Framework for MPLS in Transport Networks",
              RFC 5921, July 2010.


Authors' Addresses

   Elisa Bellagamba (editor)
   Ericsson
   Torshamnsgatan 48
   Kista,   164 40
   Sweden

   Email: elisa.bellagamba@ericsson.com


   Loa Andersson
   Ericsson
   Torshamnsgatan 48
   Kista,   164 40
   Sweden

   Phone:
   Email: loa.andersson@ericsson.com


   Pontus Skoldstrom (editor)
   Acreo AB
   Electrum 236
   Kista,   164 40
   Sweden

   Phone: +46 8 6327731
   Email: pontus.skoldstrom@acreo.se











Bellagamba, et al.      Expires January 12, 2012               [Page 20]


Internet-Draft       Extensions for MPLS-TP OAM Conf           July 2011


   Dave Ward
   Juniper


   Phone:
   Email: dward@juniper.net


   John Drake
   Juniper


   Phone:
   Email: jdrake@juniper.net





































Bellagamba, et al.      Expires January 12, 2012               [Page 21]