Network Work group N. Kumar
Internet-Draft C. Pignataro
Intended status: Standards Track Cisco Systems, Inc.
Expires: July 21, 2017 N. Akiya
Big Switch Networks
L. Zheng
M. Chen
Huawei Technologies
G. Mirsky
Ericsson
January 17, 2017
BIER Ping and Trace
draft-ietf-bier-ping-01
Abstract
Bit Index Explicit Replication (BIER) is an architecture that
provides optimal multicast forwarding through a "BIER domain" without
requiring intermediate routers to maintain any multicast related per-
flow state. BIER also does not require any explicit tree-building
protocol for its operation. A multicast data packet enters a BIER
domain at a "Bit-Forwarding Ingress Router" (BFIR), and leaves the
BIER domain at one or more "Bit-Forwarding Egress Routers" (BFERs).
The BFIR router adds a BIER header to the packet. The BIER header
contains a bit-string in which each bit represents exactly one BFER
to forward the packet to. The set of BFERs to which the multicast
packet needs to be forwarded is expressed by setting the bits that
correspond to those routers in the BIER header.
This document describes the mechanism and basic BIER OAM packet
format that can be used to perform failure detection and isolation on
BIER data plane.
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
Kumar, et al. Expires July 21, 2017 [Page 1]
Internet-Draft BIER Ping January 2017
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 21, 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
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
2. Conventions used in this document . . . . . . . . . . . . . . 3
2.1. Terminology . . . . . . . . . . . . . . . . . . . . . . . 3
2.2. Requirements notation . . . . . . . . . . . . . . . . . . 4
3. BIER OAM . . . . . . . . . . . . . . . . . . . . . . . . . . 4
3.1. BIER OAM message format . . . . . . . . . . . . . . . . . 4
3.2. Return Code . . . . . . . . . . . . . . . . . . . . . . . 7
3.3. BIER OAM TLV . . . . . . . . . . . . . . . . . . . . . . 8
3.3.1. Original SI-BitString TLV . . . . . . . . . . . . . . 8
3.3.2. Target SI-BitString TLV . . . . . . . . . . . . . . . 9
3.3.3. Incoming SI-BitString TLV . . . . . . . . . . . . . . 10
3.3.4. Downstream Mapping TLV . . . . . . . . . . . . . . . 11
3.3.5. Responder BFER TLV . . . . . . . . . . . . . . . . . 14
3.3.6. Responder BFR TLV . . . . . . . . . . . . . . . . . . 15
3.3.7. Upstream Interface TLV . . . . . . . . . . . . . . . 15
3.3.8. Reply-To TLV . . . . . . . . . . . . . . . . . . . . 16
4. Procedures . . . . . . . . . . . . . . . . . . . . . . . . . 17
4.1. BIER OAM Processing . . . . . . . . . . . . . . . . . . . 17
4.2. Per BFER ECMP Discovery . . . . . . . . . . . . . . . . . 17
4.3. Sending BIER Echo Request . . . . . . . . . . . . . . . . 18
4.4. Receiving BIER Echo Request . . . . . . . . . . . . . . . 19
4.5. Sending Echo Reply . . . . . . . . . . . . . . . . . . . 21
4.6. Receiving Echo Reply . . . . . . . . . . . . . . . . . . 22
5. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 22
5.1. Message Types, Reply Modes, Return Codes . . . . . . . . 22
5.2. TLVs . . . . . . . . . . . . . . . . . . . . . . . . . . 22
Kumar, et al. Expires July 21, 2017 [Page 2]
Internet-Draft BIER Ping January 2017
6. Security Considerations . . . . . . . . . . . . . . . . . . . 23
7. Acknowledgement . . . . . . . . . . . . . . . . . . . . . . . 23
8. Contributing Authors . . . . . . . . . . . . . . . . . . . . 23
9. References . . . . . . . . . . . . . . . . . . . . . . . . . 23
9.1. Normative References . . . . . . . . . . . . . . . . . . 23
9.2. Informative References . . . . . . . . . . . . . . . . . 24
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 25
1. Introduction
[I-D.ietf-bier-architecture] introduces and explains BIER
architecture that provides optimal multicast forwarding through a
"BIER domain" without requiring intermediate routers to maintain any
multicast related per-flow state. BIER also does not require any
explicit tree-building protocol for its operation. A multicast data
packet enters a BIER domain at a "Bit-Forwarding Ingress Router"
(BFIR), and leaves the BIER domain at one or more "Bit-Forwarding
Egress Routers" (BFERs). The BFIR router adds a BIER header to the
packet. The BIER header contains a bit-string in which each bit
represents exactly one BFER to forward the packet to. The set of
BFERs to which the multicast packet needs to be forwarded is
expressed by setting the bits that correspond to those routers in the
BIER header.
This document describes the mechanism and basic BIER OAM packet
format that can be used to perform failure detection and isolation on
BIER data plane without any dependency on other layers like IP layer.
2. Conventions used in this document
2.1. Terminology
BFER - Bit Forwarding Egress Router
BFIR - Bit Forwarding Ingress Router
BIER - Bit Index Explicit Replication
ECMP - Equal Cost Multi-Path
OAM - Operation, Administration and Maintenance
SI - Set Identifier
Kumar, et al. Expires July 21, 2017 [Page 3]
Internet-Draft BIER Ping January 2017
2.2. Requirements notation
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 OAM
BIER OAM is defined in a way that it stays within BIER layer by
following directly the BIER header without mandating the need for IP
header. [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 OAM, the "Proto" field will be set to 5 as defined in
[I-D.ietf-bier-mpls-encapsulation]
3.1. BIER OAM message format
The BIER OAM packet header format that follows BIER header 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 | Message Type | Proto | Reserved |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
~ Message Type Dependent Data ~
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Ver
Set to 1.
Message Type
This document defines the following Message Types:
Type Value Field
-------- ---------------
1 BIER Echo Request
2 BIER Echo Reply
Proto
This field is used to define if there is any data packet
immediately following the OAM payload which is used for passive
Kumar, et al. Expires July 21, 2017 [Page 4]
Internet-Draft BIER Ping January 2017
OAM functionality. This field is set to 0 if there is no data
packet following OAM payload.
The Echo Request/Reply 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 ~
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
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's
clock) 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
Kumar, et al. Expires July 21, 2017 [Page 5]
Internet-Draft BIER Ping January 2017
Protocol format. Any other value SHOULD be considered as sanity
check failure.
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 packet
When Reply mode is set to 1, the receiver will not send any reply.
This is used for unidirectional path validation. The Reply mode by
default would be set to 2 and the Responder BFR will encapsulate the
Echo reply payload with IP header. When the Initiator intend to
validate the return BIER path, the Reply mode is set to 3 so that the
Responder BFR will encapsulate the Echo Reply with BIER header.
Return Code
Set to zero if Type is "BIER Echo Request". Set to one of the
value defined in section 3.2, if Type is "BIER Echo Reply".
Return subcode
To Be updated.
Sender's Handle, Sequence number and Timestamp
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.
The Sequence number is assigned by the Initiator and can be used
to detect any missed replies.
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
Carries the TLVs as defined in Section 3.3.
Kumar, et al. Expires July 21, 2017 [Page 6]
Internet-Draft BIER Ping January 2017
3.2. Return Code
Responder uses Return Code field to reply with validity check or
other error message to Initiator. It does not carry any meaning in
Echo Request and MUST be set to zero.
The Return Code can be one of the following:
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
"No return code" will be used by Initiator in the Echo Request. This
Value MUST NOT be used in Echo Reply.
"Malformed Echo Request received" will be used by any BFR if the
received Echo Request packet is not properly formatted.
When any TLV included in the Echo Request is not understood by
receiver, the Return code will be set to "One or more of the TLVs was
not understood" carrying the respective TLVs.
When the received header BitString in Echo Request packet contains
only its own Bit-ID, "Replying BFR is the only BFER in header
BitString" is set in the reply. This implies that the receiver is
BFER and the packet is not forwarded to any more neighbors.
When the received header BitString in Echo Request packet contains
its own Bit-ID in addition to other Bit-IDs, "Replying BFR is one of
the BFER in header BitString" is set in the reply. This implies that
the responder is a BFER and the packet is further forwarded to one or
more neighbors.
Any transit BFR will send the Echo Reply with "Packet-Forward-
Success", if the TLV in received Echo Request are understood and
forwarding table have forwarding entries for the BitString. This is
used by transit BFR during traceroute mode.
When Echo Request is received with multipath info for more than one
BFER, the return-code is set to "Invalid Multipath Info Request".
Kumar, et al. Expires July 21, 2017 [Page 7]
Internet-Draft BIER Ping January 2017
If the receiving BFER does not have any state entry in Overlay
Multicast table. For example, if there is no Opaque value in mLDP
table or S,G entry in respective PIM table, the return-code is set to
"No matching entry in forwarding table".
If the BitString cannot be matched in local forwarding table, the BFR
will use "No matching entry in forwarding table" in the reply.
If the BIER-MPLS label in received Echo Request is not the one
assigned for SI in Original SI-BitString TLV, "Set-Identifier
Mismatch" is set inorder to report the mismatch.
3.3. BIER OAM TLV
This section defines various TLVs that can be used in BIER OAM
packet. The TLVs (Type-Length-Value tuples) 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 ~
| |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
TLV Types are defined below; Length is the length of the Value field
in octets. The Value field depends on the TLV Type.
3.3.1. Original SI-BitString TLV
The Original SI-BitString TLV carries the set of BFER and carries the
same BitString that Initiator includes in BIER header.This TLV has
the following format:
Kumar, et al. Expires July 21, 2017 [Page 8]
Internet-Draft BIER Ping January 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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Type = 1 | Length = variable |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Set ID | Sub-domain ID |BS Len| Reserved |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| BitString (first 32 bits) ~
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
~ ~
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| BitString (last 32 bits) |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Set ID field is set to the Set Identifier to which the BitString
belongs to. This value is derived as defined in section 3 of
[I-D.ietf-bier-architecture]
Sub-domain ID is set to the Sub domain value to which BFER in
BitString belongs to.
BS Len is set based on the length of BitString as defined in section
3 of [I-D.ietf-bier-mpls-encapsulation]
The BitString field carries the set of BFR-IDs that Initiator will
include in the BIER header. This TLV MUST be included by Initiator
in Echo Request packet
3.3.2. Target SI-BitString TLV
The Target SI-BitString TLV carries the set of BFER from which the
Initiator expects the reply from.This TLV has the following format:
Kumar, et al. Expires July 21, 2017 [Page 9]
Internet-Draft BIER Ping January 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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Type = 2 | Length = variable |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Set ID | Sub-domain ID |BS Len| Reserved |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| BitString (first 32 bits) ~
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
~ ~
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| BitString (last 32 bits) |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Set ID field is set to the Set Identifier to which the BitString
belongs to. This value is derived as defined in section 3 of
[I-D.ietf-bier-architecture]
Sub-domain ID is set to the Sub domain value to which BFER in
BitString belongs to.
BS Len is set based on the length of BitString as defined in section
3 of [I-D.ietf-bier-mpls-encapsulation]
The BitString field carries the set of BFR-IDs of BFER(s) that
Initiator expects the response from. The BitString in this TLV may
be different from the BitString in BIER header and allows to control
the BFER responding to the Echo Request. This TLV MUST be included
by Initiator in BIER OAM packet if the Downstream Mapping TLV
(section 3.3.4) is included.
3.3.3. Incoming 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. This TLV has the following format:
Kumar, et al. Expires July 21, 2017 [Page 10]
Internet-Draft BIER Ping January 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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Type = 3 | Length = variable |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Set ID | Sub-domain ID |BS Len| Reserved |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| BitString (first 32 bits) ~
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
~ ~
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| BitString (last 32 bits) |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Set ID field is set to the Set Identifier to which the BitString
belongs to. This value is derived as defined in section 3 of
[I-D.ietf-bier-architecture]
Sub-domain ID is set to the Sub domain value to which BFER in
BitString belongs to.
BS Len is set based on the length of BitString as defined in section
3 of [I-D.ietf-bier-mpls-encapsulation]
The BitString field copies the BitString from BIER header of the
incoming Echo Request. A Responder BFR SHOULD include this TLV in
Echo Reply if the Echo Request is received with I flag set in
Downstream Mapping TLV.
An Initiator MUST NOT include this TLV in Echo Request.
3.3.4. Downstream Mapping TLV
This TLV has the following format:
Kumar, et al. Expires July 21, 2017 [Page 11]
Internet-Draft BIER Ping January 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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Type = 4 | Length = variable |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| MTU | Address Type | Flags |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Downstream Address (4 or 16 octets) |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Downstream Interface Address (4 or 16 octets) |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Sub-tlv Length | |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |
. .
. List of Sub-TLVs .
. .
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
MTU
Set to MTU value of outgoing interface.
Address Type
The Address Type indicates the address type and length of IP
address for downstream interface. The Address type is set to one
of the below:
Type Addr. Type DA Length DIA Length
------- --------------- ---------- ----------
1 IPv4 Numbered 4 4
2 IPv4 Unnumbered 4 4
3 IPv6 Numbered 16 16
4 IPv6 Unnumbered 16 4
DA Length - Downstream Address field Length
DIA Length - Downstream Interface Address field Length
Flags
The Flags field has the following format:
0 1 2 3 4 5 6 7
+-+-+-+-+-+-+-+-+
| Rsvd |I|
+-+-+-+-+-+-+-+-+
Kumar, et al. Expires July 21, 2017 [Page 12]
Internet-Draft BIER Ping January 2017
When I flag is set, the Responding BFR SHOULD include the Incoming
SI-BitString TLV in Echo Reply message.
Downstream Address and Downstream Interface Address
If the Address Type is 1, the Downstream Address MUST be set to
IPV4 BFR-Prefix of downstream BFR and Downstream Interface Address
is set to downstream interface address.
If the Address Type is 2, the Downstream Address MUST be set to
IPV4 BFR-Prefix of downstream BFR and Downstream Interface Address
is set to the index assigned by upstream BFR to the interface.
If the Address Type is 3, the Downstream Address MUST be set to
IPV6 BFR-Prefix of downstream BFR and Downstream Interface Address
is set to downstream interface address.
If the Address Type is 4, the Downstream Address MUST be set to
IPv6 BFR-Prefix of downstream BFR and Downstream Interface Address
is set to index assigned by upstream BFR to the interface.
3.3.4.1. Downstream Detailed Mapping Sub-TLVs
This section defines the optional Sub-TLVs that can be included in
Downstream Mapping TLV.
Sub-TLV Type Value
--------------- --------------
1 Multipath Entropy Data
2 Egress BitString
3.3.4.1.1. Multipath Entropy Data
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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|M| Reserved | |
+-+-+-+-+-+-+-+-+-+ |
| |
| (Multipath Information) |
| |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
M Flag
Kumar, et al. Expires July 21, 2017 [Page 13]
Internet-Draft BIER Ping January 2017
This flag is set to 0 if all packets will be forwarded out through
interface defined in Downstream Mapping TLV. When set to 1,
Multipath Information will be defined with Bit masked Entropy
data.
Multipath Information
Entropy Data encoded as defined in section x3.
3.3.4.1.2. Egress BitString
This Sub-TLV MAY be included by Responder BFR with the rewritten
BitString in outgoing interface as defined in section 6.1 of
[I-D.ietf-bier-architecture]
0 1 2 3
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Set ID | Sub-domain ID |BS Len| Reserved |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| BitString (first 32 bits) ~
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
~ ~
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| BitString (last 32 bits) |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
3.3.5. 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.
This TLV 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 = 5 | Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Reserved | BFR-ID |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
BFR-ID
The BFR-ID field carries the BFR-ID of replying BFER. This TLV
MAY be included by Responding BFER in BIER Echo Reply packet.
Kumar, et al. Expires July 21, 2017 [Page 14]
Internet-Draft BIER Ping January 2017
3.3.6. 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 BFR-
ID. This TLV 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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| TLV Type = 6 | Length = variable |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Reserved | Address Type |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| |
~ BFR-Prefix (4 or 16 bytes) ~
| |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Length
The Length field varies depending on the Address Type.
Address Type
Set to 1 for IPv4 or 2 for IPv6.
BFR-Prefix
Carries the local BFR-Prefix of the replying BFR. This TLV MAY be
included by Responding BFR in BIER Echo Reply packet.
3.3.7. Upstream Interface TLV
The Upstream Interface TLV will be included by the replying BFR in
Echo Reply. This is used to identify the incoming interface and the
BIER-MPLS label in the incoming Echo Request. This TLV have the
following format:
Kumar, et al. Expires July 21, 2017 [Page 15]
Internet-Draft BIER Ping January 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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| TLV Type = 7 | Length = variable |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Reserved | Address Type |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| |
~ Upstream Address (4 or 16 bytes) ~
| |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Length
The Length field varies depending on the Address Type.
Address Type
Set to 1 for IPv4 numbered, 2 for IPv4 Unnumbered 3 for IPv6
numbered or 4 for IPv6 Unnumbered.
Upstream Address
As defined in Section 3.3.4
3.3.8. 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
2. The IP address will be used to generate Echo Reply. This TLV
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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| TLV Type = 8 | Length = variable |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Reserved | Address Type |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| |
~ Reply-To Address (4 or 16 bytes) ~
| |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Length
The Length field varies depending on the Address Type.
Kumar, et al. Expires July 21, 2017 [Page 16]
Internet-Draft BIER Ping January 2017
Address Type
Set to 1 for IPv4 or 2 for IPv6.
Reply-To Address
Set to any locally configured address to which the Echo reply
should be sent to.
4. Procedures
This section describes aspects of Ping and traceroute operations.
While this document explains the behavior when Reply mode is "Reply
via BIER packet", the future version will be updated with details
about the format when the reply mode is "Reply via IP/UDP packet".
4.1. BIER OAM Processing
A BIER 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.
4.2. Per BFER ECMP Discovery
As defined in [I-D.ietf-bier-architecture], BIER follows unicast
forwarding path and allows load balancing over ECMP paths between
BFIR and BFER. BIER OAM MUST support ECMP path discovery between a
BFIR and a given BFER and MUST support path validation and failure
detection of any particular ECMP path between BFIR and BFER.
[I-D.ietf-bier-mpls-encapsulation] proposes the BIER header with
Entropy field that can be leveraged to exercise all ECMP paths.
Initiator/BFIR will use traceroute message to query each hop about
the Entropy information for each downstream paths. To avoid
complexity, it is suggested that the ECMP query is performed per BFER
by carrying required information in BIER OAM message.
Initiator MUST include Multipath Entropy Data Sub-TLV in Downstream
Mapping TLV. It MUST also include the BFER in BitString TLV to which
the Multipath query is performed.
Any transit BFR will reply back with Bit-masked Entropy for each
downstream path as defined in [RFC4379]
Kumar, et al. Expires July 21, 2017 [Page 17]
Internet-Draft BIER Ping January 2017
4.3. Sending BIER Echo Request
Initiator MUST set the Message Type as 1 and Return Code as 0. The
Proto field in OAM packet MUST be set to 0. The choice of Sender's
Handle and Sequence number is a local matter to Initiator and SHOULD
increment the Sequence number by 1 for every subsequent Echo Request.
The QTF field is set to Initiator's local timestamp format and
TimeStamp Sent field is set to the time that the Echo Request is
sent.
Initiator MUST include Original SI-BitString TLV. Initiator MUST NOT
include more than one Original SI-BitString TLV. Initiator infers
the Set Identifier value and Sub-domain ID value from the respective
BitString that will be included in BIER header of the packet and
includes the values in "SI" and Sub-Domain ID fields respectively.
In Ping mode, Initiator MAY include Target SI-BitString TLV to
control the responding BFER(s) by listing all the BFERs from which
the Initiator expects a response. In trace route mode, Initiator MAY
include Target SI-Bitstring TLV to control the path trace towards any
specific BFER or set of BFERs. 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
unset the respective BFR-id from Target SI-BitString for any
subsequent Echo Request.
When the Reply mode is set to 2, Initiator MUST include Reply-To TLV
(section 3.3.8) in the Echo Request. Initiator MUST also listen to
the UDP port defined in this TLV and process any segment received
with destination port as value defined in the TLV and sent to control
plane for BIER OAM payload processing.
Initiator MAY include Downstream Mapping TLV (section 3.3.4) 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 id.
Initiator MUST encapsulate the OAM packet with BIER header and MUST
set the Proto as 5 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.
Kumar, et al. Expires July 21, 2017 [Page 18]
Internet-Draft BIER Ping January 2017
4.4. Receiving BIER Echo Request
Sending a BIER OAM Echo Request to control plane for payload
processing is triggered as mentioned in section 4.1.
Any BFR on receiving Echo Request MUST send Echo Reply with Return
Code set to "Malformed Echo Request received", if the packet fails
sanity check. If the packet sanity check is fine, it SHOULD
initiates the below set of variables:
Reply-Flag
This flag is initially set to 1.
Interface-I
The incoming interface on which the Echo Request was received.
This may be used to validate the DDMAP info and to populate the
Upstream Interface TLV.
BIER-Label-L
The BIER-MPLS Label received as the top label on received Echo
Request. This may be used to validate if the packet is traversing
the desired Set Identifier and sub-domain path.
Header-H
The BIER header from the received Echo Request. This may be used
to validate the DDMAP info and to populate the Incoming SI-
BitString TLV. In addition, it can be used to perform Entropy
calculation considering different field in header and reply via
Multipath Entropy Data Sub-TLV.
BFR MUST initialize Best-return-code variable to null value.
BFR will populate Interface-I with interface over which the Echo
Request is received, top label in the MPLS stack of the received Echo
Request to BIER-Label-L, and the BIER header to BIER-Header. If the
received Echo Request carries Target SI-BitString TLV, a BFR SHOULD
run boolean NAD operation between BitString in Header-H and BitString
in Target SI-BitString TLV. If the resulting BitString is all-zero,
reset Return-Flag=0 and go to section 4.5. Else:
o If the BIER-Label-L does not correspond to the local label
assigned for {sub-domain, BitStringLen, SI} in Original SI-
BitString TLV, Set the Best-return-code to "Set-Identifier
Mismatch" and Go to section 4.5.
Kumar, et al. Expires July 21, 2017 [Page 19]
Internet-Draft BIER Ping January 2017
* /* This detects any BIER-Label to {sub-domain, BitStringLen,
SI} synchronization problem in the upstream BFR causing any
unintended packet leak between sub-domains */
o Set the Best-return-code to "One or more of the TLVs was not
understood", if any of the TLVs in Echo Request message is not
understood. Go to section 4.5.
o If the BitString in Header-H does not match the BitString in
Egress BitString Sub-TLV of DDMAP TLV, set the Best-return-code to
ERR-TBD. When there are more than one DDMAP TLV in the received
Request packet, the Downstream Address and Downstream Interface
Address should be matched with Interface-I to identify the right
DDMAP TLV and then perform the BitString match.
* /* This detects any deviation between in BIER control plane and
BIER forwarding plane in the previous hop that may result in
loop or packet duplication. */
o Set the Best-return-code to "Invalid Multipath Info Request", when
the DDMAP TLV carries Multipath Entropy Data Sub-TLV and if the
Target SI-BitString TLV in the received Echo Request carries more
than 1 BFER id. Go to section 4.5. Else, list the ECMP
downstream neighbors to reach BFR-id in Target SI-BitString TLV,
calculate the Entropy considering the BitString in Header-H and
Multipath Entropy Data Sub-TLV from received Echo Request. Store
the Data for each Downstream interface in temporary variable. Set
the Best-return-code to 5 (Packet-Forward-Success) and goto
Section 4.5
* /* This instructs to calculate the Entropy Data for each
downstream interface to reach the BFER in Target SI-BitString
TLV by considering the incoming BitString and Entropy Data.*/
o Set the Best-return-code to "Replying router is the only BFER in
BIER header Bitstring", and go to section 4.5 if the responder is
BFER and there is no more bits in BIER header Bitstring left for
forwarding.
o Set the Best-return-code to "Replying router is one of the BFER in
BIER header Bitstring", and include Downstream Mapping TLV, if the
responder is BFER and there are more bits in BitString left for
forwarding. In addition, include the Multipath information as
defined in Section 4.2 if the received Echo Request carries
Multipath Entropy Data Sub-TLV. Go to section 4.5.
o Set the Best-return-code to "No matching entry in forwarding
table", if the forwarding lookup defined in section 6.5 of
Kumar, et al. Expires July 21, 2017 [Page 20]
Internet-Draft BIER Ping January 2017
[I-D.ietf-bier-architecture] does not match any entry for the
received BitString in BIER header.
* /* This detects any missing BFR-id in the BIER forwarding
table. It could be noted that it is difficult to detect such
missing BFR-id while sending the Request with more than one
BFR-id in BitString and so may need to just include the BFER id
that is not responding to detect such failure.*/
o Set the Best-return-code to "Packet-Forward-Success", and include
Downstream Mapping TLV. Go to section 4.5
4.5. Sending Echo Reply
If Return-Flag=0; BFR MUST release the variables and MUST not send
any response to the Initiator. If Return-Flag=1, proceed as below:
The Responder BFR SHOULD include the BitString from Header-H to
Incoming SI-BitString TLV and include the Set ID, Sub-domain ID and
BS Len corresponding to BIER-Label-L. Responder BFR SHOULD include
the Upstream Interface TLV and populate the address from Interface-I.
When the Best-return-code is "Replying BFR is one of the BFER in
header Bitstring", it MUST include Responder BFER TLV.
If the received Echo Request had DDMAP with Multipath Entropy Data
Sub-TLV, Responder BFR MUST include DDMAP as defined in
Section 3.3.4 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 DDMAP TLV.
If the received Echo Request had DDMAP without Multipath Entropy
Data Sub-TLV, Responder BFR MUST include DDMAP as defined in
Section 3.3.4 for each outgoing interface over which the packet
will be replicated. For each outgoing interface, respective
Egress BitString MUST be included in DDMAP TLV.
When the Best-return-code is "Replying BFR is the only BFER in header
Bitstring", it MUST include Responder BFER TLV.
Responder MUST set the Message Type as 2 and Return Code as Best-
return-code. The Proto field MUST be set to 0.
The Echo Reply can be sent either as BIER-encapsulated or IP/UDP
encapsulated depending on the Reply mode in received Echo Request.
When the Reply mode in received Echo Request is set to 3, Responder
appends BIER header listing the BitString with BFIR ID (from Header-
Kumar, et al. Expires July 21, 2017 [Page 21]
Internet-Draft BIER Ping January 2017
H), set the Proto to 5 and set the BFIR as 0. 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.
4.6. Receiving Echo Reply
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.
If receiving Echo Reply have Downstream Mapping, Initiator SHOULD
copy the same to subsequent Echo Request(s).
If one of the Echo Reply is received with Return Code as "Replying
BFR is one of the BFER in header Bitstring", it SHOULD reset the BFR-
id of the responder from Target SI-BisString TLV in subsequent Echo
Request.
/* This helps avoiding any BFR that is both BFER and also transit
BFR to continuously responding with Echo Reply.*/
5. IANA Considerations
This document request UDP port TBD1 to be allocated by IANA for BIER
Echo.
This document request the IANA for creation and management of below
registries:
5.1. Message Types, Reply Modes, Return Codes
This document request to assign the Message Types and Reply mode
mentioned in section 3.1, , Return code mentioned in Section 3.2.
5.2. TLVs
The TLVs and Sub-TLVs defined in this document is not limited to Echo
Request or Reply message types and is applicable for other message
types. The TLVs and Sub-TLVs requested by this document for IANA
consideration are the following:
Kumar, et al. Expires July 21, 2017 [Page 22]
Internet-Draft BIER Ping January 2017
Type Sub-Type Value Field
------- -------- -----------
1 Original SI-BitString
2 Target SI-BitString
3 Incoming SI-BitString
4 Downstream Mapping
4 1 Multipath Entropy Data
4 2 Egress BitString
5 Responder BFER
6 Responder BFR
7 Upstream Interface
6. Security Considerations
The security consideration for BIER Ping is similar to ICMP or LSP
Ping. AS like ICMP or LSP ping, BFR may be exposed to Denial-of-
service attacks and it is RECOMMENDED to regulate the BIER Ping
packet flow to control plane. A rate limiter SHOULD be applied to
avoid any attack.
As like ICMP or LSP Ping, a traceroute can be used to obtain network
information. It is RECOMMENDED that the implementation check the
integrity of BFIR of the Echo messages against any local secured list
before processing the message further
7. Acknowledgement
The authors would like to thank Antoni Przygienda, Eric Rosen, Faisal
Iqbal and Jeffrey (Zhaohui) Zhang for thier review and comments.
8. Contributing Authors
TBD
9. References
9.1. Normative References
[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-05 (work in
progress), October 2016.
Kumar, et al. Expires July 21, 2017 [Page 23]
Internet-Draft BIER Ping January 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-04 (work
in progress), September 2016.
[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
Requirement Levels", BCP 14, RFC 2119,
DOI 10.17487/RFC2119, March 1997,
<http://www.rfc-editor.org/info/rfc2119>.
[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>.
9.2. Informative References
[RFC0792] Postel, J., "Internet Control Message Protocol", STD 5,
RFC 792, DOI 10.17487/RFC0792, September 1981,
<http://www.rfc-editor.org/info/rfc792>.
[RFC6291] Andersson, L., van Helvoort, H., Bonica, R., Romascanu,
D., and S. Mansfield, "Guidelines for the Use of the "OAM"
Acronym in the IETF", BCP 161, RFC 6291,
DOI 10.17487/RFC6291, June 2011,
<http://www.rfc-editor.org/info/rfc6291>.
[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>.
Kumar, et al. Expires July 21, 2017 [Page 24]
Internet-Draft BIER Ping January 2017
[RFC6425] Saxena, S., Ed., Swallow, G., Ali, Z., Farrel, A.,
Yasukawa, S., and T. Nadeau, "Detecting Data-Plane
Failures in Point-to-Multipoint MPLS - Extensions to LSP
Ping", RFC 6425, DOI 10.17487/RFC6425, November 2011,
<http://www.rfc-editor.org/info/rfc6425>.
Authors' Addresses
Nagendra Kumar
Cisco Systems, Inc.
7200 Kit Creek Road
Research Triangle Park, NC 27709
US
Email: naikumar@cisco.com
Carlos Pignataro
Cisco Systems, Inc.
7200 Kit Creek Road
Research Triangle Park, NC 27709-4987
US
Email: cpignata@cisco.com
Nobo Akiya
Big Switch Networks
Japan
Email: nobo.akiya.dev@gmail.com
Lianshu Zheng
Huawei Technologies
China
Email: vero.zheng@huawei.com
Mach Chen
Huawei Technologies
Email: mach.chen@huawei.com
Kumar, et al. Expires July 21, 2017 [Page 25]
Internet-Draft BIER Ping January 2017
Greg Mirsky
Ericsson
Email: gregory.mirsky@ericsson.com
Kumar, et al. Expires July 21, 2017 [Page 26]
