[Docs] [txt|pdf] [Tracker] [Email] [Diff1] [Diff2] [Nits]

Versions: 00 01 02

Networking Working Group                                       Ran. Chen
Internet-Draft                                              Shaofu. Peng
Intended status: Standards Track                         ZTE Corporation
Expires: November 4, 2017                                    May 3, 2017


                         BIER-TE Ping and Trace
                       draft-chen-bier-te-ping-02

Abstract

   Bit Index Explicit Replication (BIER)-TE shares architecture and
   packet formats with BIER as described in
   [I-D.ietf-bier-architecture].  BIER-TE forwards and replicates
   packets based on a BitString in the packet header, but every
   BitPosition of the BitString of a BIER-TE packet indicates one or
   more adjacencies.

   This document describes the mechanism and basic BIER-TE OAM packet
   format that can be used to perform Ping and Traceroute on BIER-TE
   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 November 4, 2017.

Copyright Notice

   Copyright (c) 2017 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



Chen & Peng             Expires November 4, 2017                [Page 1]


Internet-Draft           BIER-TE Ping and Trace                 May 2017


   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
   3.  BIER-TE OAM Packet format . . . . . . . . . . . . . . . . . .   3
     3.1.  Target FEC Stack  . . . . . . . . . . . . . . . . . . . .   5
       3.1.1.  BIER-TE forward_connected TLV . . . . . . . . . . . .   6
       3.1.2.  BIER-TE local_decap TLV . . . . . . . . . . . . . . .   7
       3.1.3.  BIER-TE forward_routed TLV  . . . . . . . . . . . . .   7
     3.2.  Downstream Mapping TLV  . . . . . . . . . . . . . . . . .   8
       3.2.1.  Downstream Mapping Sub-TLVs . . . . . . . . . . . . .   8
         3.2.1.1.  Multipath Entropy Data  . . . . . . . . . . . . .   9
         3.2.1.2.  Egress BitString sub-TLV  . . . . . . . . . . . .   9
         3.2.1.3.  FEC Stack Change Sub-TLV  . . . . . . . . . . . .   9
     3.3.  Original SI-BitString TLV . . . . . . . . . . . . . . . .  10
     3.4.  Target SI-BitString TLV . . . . . . . . . . . . . . . . .  11
     3.5.  Responder BFER TLV  . . . . . . . . . . . . . . . . . . .  11
     3.6.  Responder BFR TLV . . . . . . . . . . . . . . . . . . . .  11
     3.7.  Reply-To TLV  . . . . . . . . . . . . . . . . . . . . . .  11
   4.  BIER-TE OAM Processing  . . . . . . . . . . . . . . . . . . .  11
     4.1.  Sending BIER Echo Request . . . . . . . . . . . . . . . .  11
     4.2.  Receiving BIER Echo Request . . . . . . . . . . . . . . .  12
     4.3.  Sending Echo Reply  . . . . . . . . . . . . . . . . . . .  14
     4.4.  Receiving Echo Reply  . . . . . . . . . . . . . . . . . .  15
   5.  Security Consideration  . . . . . . . . . . . . . . . . . . .  15
   6.  Acknowledgements  . . . . . . . . . . . . . . . . . . . . . .  15
   7.  IANA Considerations . . . . . . . . . . . . . . . . . . . . .  15
   8.  References  . . . . . . . . . . . . . . . . . . . . . . . . .  15
     8.1.  Normative references  . . . . . . . . . . . . . . . . . .  15
     8.2.  Informative references  . . . . . . . . . . . . . . . . .  16
   Authors' Addresses  . . . . . . . . . . . . . . . . . . . . . . .  17

1.  Introduction

   [I-D.ietf-bier-architecture] introduces and explains BIER-TE
   architecture that provides optimal multicast forwarding through a
   "BIER-TE domain" without requiring intermediate routers to maintain
   any multicast related per-flow state.  BIER-TE forwards and
   replicates packets based on a BitString in the packet header, but
   every BitPosition of the BitString of a BIER-TE packet indicates one
   or more adjacencies.




Chen & Peng             Expires November 4, 2017                [Page 2]


Internet-Draft           BIER-TE Ping and Trace                 May 2017


   This document describes the mechanism and basic BIER-TE OAM packet
   format that can be used to perform Ping and Traceroute on BIER-TE
   network.

   This document is a supplement to [I-D.kumarzheng-bier-ping].BIER-MPLS
   [I-D.ietf-bier-mpls-encapsulation] defines a 4-bit field as "Proto"
   to identify the payload following BIER header.  When the payload is
   BIER-TE OAM, the "Proto" field will be set to 6 as defined in this
   document.

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.

3.  BIER-TE OAM Packet format

   The BIER-TE OAM packet header format is similar with the BIER OAM
   header as described in [I-D.kumarzheng-bier-ping].

   The BIER-TE OAM packet header 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
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     | Ver | Echo Req/Rep | Proto |           Reserved               |
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     | QTF | RTF | Reply mode | Return Code |      Return Subcode    |
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     |                         Sender's Handle                       |
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     |                         Sequence Number                       |
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     |                          TimeStamp Sent                       |
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     |                          TimeStamp Sent                       |
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     |                         TimeStamp Received                    |
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     |                         TimeStamp Received                    |
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     ~                                       TLVs                    ~
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+


   Ver:Set to 1.



Chen & Peng             Expires November 4, 2017                [Page 3]


Internet-Draft           BIER-TE Ping and Trace                 May 2017


   Proto:Set to 0 for Echo Request/Reply header.

   QTF:Querier Timestamp Format.When set to 2, the Timestamp Sent field
   is (in seconds and microseconds, according to the Initiator'sclock)
   in NTP format [RFC5905].  When set to 3, the timestamp format is in
   IEEE 1588-2008 (1588v2) Precision Time Protocol format.  Any other
   value SHOULD be considered as sanity check failure.

   RTF:Responder Timestamp Format.  When set to 2, the Timestamp
   Received field is (in seconds and microseconds, according to the
   Initiator's clock) in NTP format [RFC5905].  When set to 3, the
   timestamp format is in IEEE 1588-2008 (1588v2) Precision Time.

   Reply mode:The Reply mode is set to one of the below:


                     Value        Meaning
                   --------     ---------------
                       1       Do not Reply
                       2       Reply via IPv4/IPv6 UDP packet.
                       3       Reply via BIER-TE packet


   Return Code:Set to zero if Type is " BIER Echo Request".  Set to the
   following value, if Type is "BIER Echo Reply".


              Value      Value Meaning
           --------    ---------------
               0        No return code
               1        Malformed Echo Request received
               2        One or more of the TLVs was not understood
               3        Replying BFR is the only BFER in header Bitstring
               4        Replying BFR is one of the BFER in header Bitstring
               5        Packet-Forward-Success
               6        Invalid Multipath Info Request
               8        No matching entry in forwarding table.
               9        Set-Identifier Mismatch
               10       Replying BFR is not in the path to any target BFER
               11       Mapping for this FEC is not the given bitposition in bitstring

   Return subcode:To Be updated.

   Sender's Handle:The Sender's Handle is filled by the Initiator, and
   returned unchanged by responder BFR.  This is used for matching the
   replies to the request.





Chen & Peng             Expires November 4, 2017                [Page 4]


Internet-Draft           BIER-TE Ping and Trace                 May 2017


   Sequence number:The Sequence number is assigned by the Initiator and
   can be used to detect any missed replies.

   Timestamp:The Timestamp Sent is the time when the Echo Request is
   sent.  The TimeStamp Received in Echo Reply is the time (accordingly
   to responding BFR clock) that the corresponding Echo Request was
   received.  The format depends on the QTF/RTF value.

   TLVs have the following format:


                     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                |             Length             |
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     |                            Value                              |
     .                                                               .
     .                                                               .
     .                                                               .
     |                                                               |
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

   Length is the length of the Value field in octets.  The Value field
   depends on the TLV Type.

   A description of the Types and Values for TLLVs are given below:


                  Type#               value field
               --------          ---------------------------------
                   1                Target FEC Stack
                   2                Downstream Mapping
                   3                Original SI-BitString TLV
                   4                Target SI-BitString TLV
                   5                Responder BFER TLV
                   6                Responder BFR TLV
                   7                Reply-To TLV

3.1.  Target FEC Stack

   A Target FEC Stack is a list of sub-TLVs.









Chen & Peng             Expires November 4, 2017                [Page 5]


Internet-Draft           BIER-TE Ping and Trace                 May 2017


                 Sub-Length         Value Field
                --------           -----------------
                   29               BIER-TE forward_connected  TLV
                   30               BIER-TE local_decap TLV
                   31               BIER-TE forward_routed TLV


   Other FEC Types will be defined as needed.

3.1.1.  BIER-TE forward_connected TLV

   The format is as 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
       +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
       |              Type             |        Length                 |
       +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
       |    Protocol   |                      Reserved                 |
       +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
       |                Local Interface ID (4 or 16 octets)            |
       +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
       |                Remote Interface ID (4 or 16 octets)           |
       +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
       ~                                                               ~
       |          Advertising Node Identifier (4 or 6 octets)          |
       +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
       ~                                                               ~
       |             Receiving Node Identifier (4 or 6 octets)         |
       +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

   Local Interface ID

   Local Interface ID is assigned by local BFR for a link on which
   Adjacency ID is bound.  This field is set to local link address (IPv4
   or IPv6).

   Remote Interface ID

   Remote Interface ID is assigned by remote BFR for a link on which
   Adjacency ID is bound.  This field is set to remote link address
   (IPv4 or IPv6).

   Advertising Node Identifier





Chen & Peng             Expires November 4, 2017                [Page 6]


Internet-Draft           BIER-TE Ping and Trace                 May 2017


   Advertising Node Identifier is the advertising node identifier.  When
   Protocol is set to 1, then the 32 rightmost bits represent OSPF
   Router ID and if protocol is set to 2, this field carries 48 bit ISIS
   System ID.

   Receiving Node Identifier

   Receiving Node Identifier is downstream node identifier.  When
   Protocol is set to 1, then the 32 rightmost bits represent OSPF
   Router ID and if protocol is set to 2, this field carries 48 bit ISIS
   System ID.

3.1.2.  BIER-TE local_decap TLV

   The format is as 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
       +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
       |              Type             |        Length                 |
       +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
       |    Protocol   |                      Reserved                 |
       +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
       ~                                                               ~
       |          Advertising Node Identifier (4 or 6 octets)          |
       +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+


   Advertising Node Identifier

   Advertising Node Identifier is the advertising node identifier.  When
   Protocol is set to 1, then the 32 rightmost bits represent OSPF
   Router ID and if protocol is set to 2, this field carries 48 bit ISIS
   System ID.

3.1.3.  BIER-TE forward_routed TLV

   The ipv4 format is as below:











Chen & Peng             Expires November 4, 2017                [Page 7]


Internet-Draft           BIER-TE Ping and Trace                 May 2017


        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
       +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
       |                       BFR IPv4 Prefix                         |
       +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
       |Prefix Length  |                  Reserved                     |
       +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

   IPv4 Prefix:This field carries the IPv4 prefix.

   Prefix Length is one octet, it gives the length of prefix in bits.

   The ipv6 format is as 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
       +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
       |                                                               |
       |                   BFR IPv6 Prefix                             |
       |                                                               |
       |                                                               |
       +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
       |Prefix Length  |                      Reserved                 |
       +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

   IPv6 Prefix:This field carries the IPv4 prefix.

   Prefix Length is one octet, it gives the length of prefix in bits.

3.2.  Downstream Mapping TLV

   The TLV format is similar with Downstream Detailed Mapping TLV as
   described in [I-D.kumarzheng-bier-ping].

3.2.1.  Downstream Mapping Sub-TLVs

   This section defines the optional Sub-TLVs that can be included in.


                     Sub-TLV Type              Value
                     ---------------   ------------------------
                            1           Multipath Entropy Data
                            2           Egress BitString
                            3.          FEC stack change






Chen & Peng             Expires November 4, 2017                [Page 8]


Internet-Draft           BIER-TE Ping and Trace                 May 2017


3.2.1.1.  Multipath Entropy Data

   The format is as 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
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |Multipath Type |       Multipath Length        |Reserved (MBZ) |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |                                                               |
      |                  (Multipath Information)                      |
      |                                                               |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

   The multipath data sub-TLV includes Multipath Information.

3.2.1.2.  Egress BitString sub-TLV

   The format is as 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
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     |     Type      |            Length             |    Resrved    |
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     |    Set ID     | Sub-domain ID |BS Len|  Reserved              |
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     |                BitString  (first 32 bits)                     ~
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     ~                                                               ~
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     |                BitString  (last 32 bits)                      |
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

   BitString:Adjacency BitString.

3.2.1.3.  FEC Stack Change Sub-TLV

   The format and the usage is the similar with [RFC6424].

   The format is as below:








Chen & Peng             Expires November 4, 2017                [Page 9]


Internet-Draft           BIER-TE Ping and Trace                 May 2017


         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 2
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |Operation Type | Address Type  | FEC-tlv length|  Reserved     |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |           Remote Peer Address (0, 4 or 16 octets)             |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      .                                                               .
      .                         FEC TLV                               .
      .                                                               .
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+


   Operation Type

   The operation type specifies the action associated with the FEC Stack
   Change.A new operation type is defined:


                                  Type    Operation
                                 -----    -----------
                                   3        Remove

   Address type: 0.

   FEC TLV Length:Length in bytes of the FEC TLV.

   Reserved:This field is reserved for future use and MUST be set to
   zero.

   Remote Peer Address:0.

   FEC TLV

   The FEC TLV is present only when the FEC-tlv length field is nonzero.
   The FEC TLV specifies the FEC associated with the FEC stack change
   operation.  The FEC type is defined in section 3.1.

3.3.  Original SI-BitString TLV

   The Incoming SI-BitString TLV will be included by Responder BFR in
   Reply message and copies the BitString from BIER header of incoming
   Echo Request message.The format and usage is similar with Original
   SI-BitString TLV as defined in [I-D.kumarzheng-bier-ping].







Chen & Peng             Expires November 4, 2017               [Page 10]


Internet-Draft           BIER-TE Ping and Trace                 May 2017


3.4.  Target SI-BitString TLV

   The Target SI-BitString TLV carries the set of BFER's local_decap
   adjacency from which the Initiator expects the reply from.  The
   format and usage is similar with Target SI-BitString TLV as defined
   in [I-D.kumarzheng-bier-ping].

3.5.  Responder BFER TLV

   The Responder BFER TLV will be included by the BFER replying to the
   request.  This is used to identify the originator of BIER Echo Reply.
   The format and usage is similar with Responder BFER TLV as defined in
   [I-D.kumarzheng-bier-ping].

3.6.  Responder BFR TLV

   The Responder BFR TLV will be included by the transit BFR replying to
   the request.  This is used to identify the replying BFR without
   BFRID.  The format and usage is similar with Responder BFR TLV as
   defined in [I-D.kumarzheng-bier-ping].

3.7.  Reply-To TLV

   The Reply-To TLV MAY be included by the Initiator BFR in Echo
   Request.  This is used by transit BFR or BFER when the reply mode is
   the IP address will be used to generate Echo Reply.  The format and
   usage is similar with Reply-To TLV as defined in
   [I-D.kumarzheng-bier-ping].

4.  BIER-TE OAM Processing

   BIER-TE OAM packet MUST be sent to BIER control plane for OAM
   processing if one of the following conditions is true:

   o  The receiving BFR is a BFER.

   o  TTL of BIER-MPLS Label expired.

   o  Presence of Router Alert label in the label stack.

4.1.  Sending BIER Echo Request

   o  Message Type:1.

   o  Return Code:0.

   o  Proto:0.




Chen & Peng             Expires November 4, 2017               [Page 11]


Internet-Draft           BIER-TE Ping and Trace                 May 2017


   o  Sender's Handle and Sequence number:The local matter to Initiator
      and SHOULD increment the Sequence number by 1 for every subsequent
      Echo Request.

   o  QTF:Initiator's local timestamp format.

   o  TimeStamp Sent:the time that the Echo Request is sent.

   o  MUST include Original SI-BitString TLV.

   o  In Ping mode, Initiator MAY include Target SI-BitString TLV to
      control the responding BFER(s) by listing all local_decap
      adjacency id of the BFERs from which the Initiator expects a
      response.  Initiator on receiving a reply with Return code as
      "Replying BFR is the only BFER in header Bitstring" or "Replying
      router is one of the BFER in header Bitstring", SHOULD remove the
      BFER's local_decap ID from Target SI-BitString for any subsequent
      Echo Request.

   o  When the Reply mode is set to 2, Initiator MUST include Reply-To
      TLV in the Echo Request.

   o  Initiator MAY include Downstream Mapping TLV in the Echo Request
      to query additional information from transit BFRs and BFERs.  In
      case of ECMP discovery, Initiator MUST include the Multipath
      Entropy Data Sub-TLV and SHOULD set the Target SI-BitString TLV
      carrying a specific BFER's local_decap adjacency id.

   o  Initiator MUST encapsulate the OAM packet with BIER header and
      MUST set the Proto as 6 and further encapsulates with BIER-MPLS
      label.  In ping mode, the BIER-MPLS Label TTL MUST be set to 255.
      In traceroute mode, the BIER-MPLS Label TTL is set successively
      starting from 1 and MUST stop sending the Echo Request if it
      receives a reply with Return code as "Replying router is the only
      BFER in BIER header Bitstring" from all BFER listed in Target SI-
      BitString TLV.

   o  MUST PUSH the corresponding FEC to target FEC stack, which the
      push order is the same with adjacency BitPosition of the
      BitString.

4.2.  Receiving BIER Echo Request

   Reply-Flag:This flag is initially set to 1.

   Interface-I:The incoming interface on which the Echo Request was
   received.




Chen & Peng             Expires November 4, 2017               [Page 12]


Internet-Draft           BIER-TE Ping and Trace                 May 2017


   BIER-Label-L:The BIER-MPLS Label received as the top label on
   received Echo Request.

   Header-H:The BIER header from the received Echo Request.

   Best-return-code: contains the return code for the echo reply packet
   as currently best known.

   If the received Echo Request carries Target SI-BitString TLV, a BFR
   SHOULD run boolean AND operation between BitString in Header-H and
   BitString in Target SI-BitString TLV.

   If the resulting BitString is all-zero, Set Best-return-code="Mapping
   for this FEC is not the given bitposition in bitstring" and Go to
   section 4.3, Else:

   o  If the BIER-Label-L does not correspond to the local label
      assigned for {sub-domain, BitStringLen, SI} in Original
      SIBitString TLV, Set the Best-return-code to "Set-Identifier
      Mismatch" and Go to section 4.3.

   o  If any of the TLVs in Echo Request message is not understood.  Set
      the Best-return-code to "One or more of the TLVs was not
      understood" and Go to section 4.3.

   o  If the BitString in Header-H does not match the BitString in
      Egress BitString Sub-TLV of DSMAP TLV, set the Best-return-code to
      ERR-TBD and Go to section 4.3.

   o  If the forwarding lookup defined in section 6.5 of
      [I-D.ietf-bier-architecture] does not match any entry for the
      received BitString in BIER header.  Set the Best-return-code to
      "No matching entry in forwarding table" and Go to section 4.3.

   o  If any FEC which get from the matched BIFT entry is not consistent
      with the FEC get from the FEC stack at same position as entry's
      BitPosition in Header-H, Set the Best-return-code to "Mapping for
      this FEC is not the given bitposition in bitstring" and Go to
      section 4.3.

   o  If the DSMAP TLV carries Multipath Entropy Data Sub-TLV and if the
      BitString in Header-H carries more than one forward routed
      adjacency and each matches the BIFT entry.  Set the Best-return-
      code to "Invalid Multipath Info Request" and Go to section 4.3.
      Else, list the ECMP downstream neighbors to reach forward routed
      adjacency, calculate the Entropy considering the BitString in
      Header-H and Multipath Entropy Data Sub-TLV from received Echo
      Request.  Set the Best-return-code to 5 (Packet-Forward-Success).



Chen & Peng             Expires November 4, 2017               [Page 13]


Internet-Draft           BIER-TE Ping and Trace                 May 2017


   o  For all the forward_connected adjacency and local_decap adjacency
      which match the BIFT entry, FEC change sub-TLV should be carried
      in DSMAP TLV, and set the operation type filed in the FEC change
      sub-TLV to remove.

   o  For all the forward_routed adjacency which match the BIFT entry,
      if the BIFT entry indicate that not local decapsulation but
      continue forwarding the OAM packet, FEC change sub-TLV should not
      carried in DSMAP TLV.  If the BIFT entry indicate that local
      decapsulation the OAM packet, FEC change sub-TLV should be carried
      in DSMAP TLV, and set the operation type filed in the FEC change
      sub-TLV to remove.

   o  If the responder is BFER which match the local_decap BIFT, and
      there is no more bits in BIER header Bitstring left for
      forwarding.Set the Best-return-code to "Replying router is the
      only BFER in BIER header Bitstring", and go to section 4.3.

   o  If the responder is BFER which match the local_decap BIFT, and
      there are more bits in in BitString left for forwarding.  Set the
      Best-return-code to " Replying router is one of the BFER in BIER
      header Bitstring", and go to section 4.3.

4.3.  Sending Echo Reply

   o  Message Type:2.

   o  Return Code:Best-return-code.

   o  The Proto :0.

   o  When the Best-return-code is "Replying BFR is one of the BFER in
      header Bitstring", it MUST include Responder BFER TLV.

   o  If the received Echo Request had DSMAP with Multipath Entropy Data
      Sub-TLV, Responder BFR MUST include DSMAP for each outgoing
      interface over which the packet will be replicated and include the
      respective Multipath Entropy Data Sub-TLV.  For each outgoing
      interface, respective Egress BitString MUST be included in DSMAP
      TLV.

   o  If the received Echo Request had DSMAP without Multipath Entropy
      Data Sub-TLV, Responder BFR MUST include DSMAP for each outgoing
      interface over which the packet will be replicated.  For each
      outgoing interface, respective Egress BitString MUST be included
      in DSMAP TLV.





Chen & Peng             Expires November 4, 2017               [Page 14]


Internet-Draft           BIER-TE Ping and Trace                 May 2017


   o  When the Best-return-code is "Replying BFR is the only BFER in
      header Bitstring", it MUST include Responder BFER TLV.

   o  When the Reply mode in received Echo Request is set to 3,
      Responder appends BIER header listing the BitString with the
      BFIR's local_decap id and set the Proto to 6 and set the BFIR as
      0.

   o  When the Reply mode in received Echo Request is set to 2,
      Responder encapsulates with IP/UDP header.  The UDP destination
      port MUST be set to TBD1 and source port MAY be set to TBD1 or
      other random local value.  The source IP is any local address of
      the responder and destiantion IP is derived from Reply-To TLV.

4.4.  Receiving Echo Reply

   o  Initiator on receiving Echo Reply will use the Sender's Handle to
      match with Echo Request sent.  If no match is found, Initiator
      MUST ignore the Echo Reply.

   o  If receiving Echo Reply have Downstream Mapping, Initiator SHOULD
      copy the same to subsequent Echo Request(s).

   o  If one of the Echo Reply is received with Return Code as "Replying
      BFR is one of the BFER in header Bitstring", it SHOULD remove the
      BFER' s local_decap ID from Target SI-BitString for any subsequent
      Echo Request.

5.  Security Consideration

   The section will be added in next version.

6.  Acknowledgements

   TBD.

7.  IANA Considerations

   TBD.

8.  References

8.1.  Normative references








Chen & Peng             Expires November 4, 2017               [Page 15]


Internet-Draft           BIER-TE Ping and Trace                 May 2017


   [I-D.ietf-bier-architecture]
              Wijnands, I., Rosen, E., Dolganow, A., Przygienda, T., and
              S. Aldrin, "Multicast using Bit Index Explicit
              Replication", draft-ietf-bier-architecture-06 (work in
              progress), April 2017.

   [I-D.ietf-bier-mpls-encapsulation]
              Wijnands, I., Rosen, E., Dolganow, A., Tantsura, J.,
              Aldrin, S., and I. Meilik, "Encapsulation for Bit Index
              Explicit Replication in MPLS and non-MPLS Networks",
              draft-ietf-bier-mpls-encapsulation-06 (work in progress),
              December 2016.

   [I-D.ietf-bier-ospf-bier-extensions]
              Psenak, P., Kumar, N., Wijnands, I., Dolganow, A.,
              Przygienda, T., Zhang, Z., and S. Aldrin, "OSPF Extensions
              for BIER", draft-ietf-bier-ospf-bier-extensions-05 (work
              in progress), March 2017.

   [RFC0792]  Postel, J., "Internet Control Message Protocol", STD 5,
              RFC 792, DOI 10.17487/RFC0792, September 1981,
              <http://www.rfc-editor.org/info/rfc792>.

   [RFC4379]  Kompella, K. and G. Swallow, "Detecting Multi-Protocol
              Label Switched (MPLS) Data Plane Failures", RFC 4379,
              DOI 10.17487/RFC4379, February 2006,
              <http://www.rfc-editor.org/info/rfc4379>.

   [RFC5905]  Mills, D., Martin, J., Ed., Burbank, J., and W. Kasch,
              "Network Time Protocol Version 4: Protocol and Algorithms
              Specification", RFC 5905, DOI 10.17487/RFC5905, June 2010,
              <http://www.rfc-editor.org/info/rfc5905>.

   [RFC6424]  Bahadur, N., Kompella, K., and G. Swallow, "Mechanism for
              Performing Label Switched Path Ping (LSP Ping) over MPLS
              Tunnels", RFC 6424, DOI 10.17487/RFC6424, November 2011,
              <http://www.rfc-editor.org/info/rfc6424>.

8.2.  Informative references

   [I-D.eckert-bier-te-arch]
              Eckert, T., Cauchie, G., Braun, W., and M. Menth, "Traffic
              Engineering for Bit Index Explicit Replication BIER-TE",
              draft-eckert-bier-te-arch-04 (work in progress), July
              2016.






Chen & Peng             Expires November 4, 2017               [Page 16]


Internet-Draft           BIER-TE Ping and Trace                 May 2017


   [I-D.kumarzheng-bier-ping]
              Kumar, N., Pignataro, C., Akiya, N., Zheng, L., Chen, M.,
              and G. Mirsky, "BIER Ping and Trace", draft-kumarzheng-
              bier-ping-03 (work in progress), July 2016.

Authors' Addresses

   Ran Chen
   ZTE Corporation
   No.50 Software Avenue,Yuhuatai District
   Nanjing, Jiangsu Province  210012
   China

   Phone: +86 025 88014636
   Email: chen.ran@zte.com.cn


   Shaofu Peng
   ZTE Corporation

   Email: peng.shaofu@zte.com.cn






























Chen & Peng             Expires November 4, 2017               [Page 17]


Html markup produced by rfcmarkup 1.123, available from https://tools.ietf.org/tools/rfcmarkup/