Internet DRAFT - draft-cheng-pwe3-mpls-tp-dual-homing-coordination
draft-cheng-pwe3-mpls-tp-dual-homing-coordination
Network Working Group W. Cheng
Internet-Draft L. Wang
Intended status: Standards Track H. Li
Expires: May 14, 2015 China Mobile
K. Liu
Huawei Technologies
S. Davari
Broadcom Corporation
J. Dong
Huawei Technologies
A. D'Alessandro
Telecom Italia
November 10, 2014
Dual-Homing Coordination for MPLS Transport Profile (MPLS-TP)
Pseudowires Protection
draft-cheng-pwe3-mpls-tp-dual-homing-coordination-01
Abstract
In some scenarios, the MPLS Trasport Profile (MPLS-TP) Pseudowires
(PWs) are provisioned through either static configuration or
management plane, where a dynamic control plane is not available. A
fast protection mechanism for MPLS-TP PWs is needed to protect
against the failure of Attachment Circuit (AC), the failure of
Provider Edge (PE) and also the failure in the Packet Switched
Network (PSN). The framework and scenarios for dual-homing
pseudowire (PW) local protection are described in [draft-cheng-pwe3-
mpls-tp-dual-homing-protection]. This document proposes a dual-
homing coordination mechanism for MPLS-TP PWs, which is used for
state exchange and coordination between the dual-homing PEs for dual-
homing PW local protection.
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].
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
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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 May 14, 2015 .
Copyright Notice
Copyright (c) 2014 IETF Trust and the persons identified as the
document authors. All rights reserved.
This document is subject to BCP 78 and the IETF Trust's Legal
Provisions Relating to IETF Documents
(http://trustee.ietf.org/license-info) in effect on the date of
publication of this document. Please review these documents
carefully, as they describe your rights and restrictions with respect
to this document. Code Components extracted from this document must
include Simplified BSD License text as described in Section 4.e of
the Trust Legal Provisions and are provided without warranty as
described in the Simplified BSD License.
Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2
2. Overview of the Proposed Solution . . . . . . . . . . . . . . 3
3. Protocol Extensions for MPLS-TP PW Dual-Homing Protection . . 4
3.1. Information Exchange Between Dual-Homing PEs . . . . . . 4
3.2. Protection Procedures . . . . . . . . . . . . . . . . . . 7
4. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 10
5. Security Considerations . . . . . . . . . . . . . . . . . . . 10
6. References . . . . . . . . . . . . . . . . . . . . . . . . . 11
6.1. Normative References . . . . . . . . . . . . . . . . . . 11
6.2. Informative References . . . . . . . . . . . . . . . . . 11
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 12
1. Introduction
[RFC6372], [RFC6378] and [I-D.shawam-pwe3-ms-pw-protection] describe
the framework and mechanism of MPLS-TP Linear protection, which can
provide protection for the MPLS LSP and PW between the edge nodes.
These mechanisms does not protect the failure of the Attachement
Circuit (AC) or the edge nodes. [RFC6718] and [RFC6870] specifies
the PW redundancy framework and mechanism for protecting the AC or
edge node failure by adding one or more edge nodes, but it requires
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PW switchover in case of a AC failure, also PW redundancy relies on
PSN protection mechanisms to protect the failure of PW.
In some scenarios such as mobile backhauling, the MPLS PWs are
provisioned with dual-homing topology, in which at least the CE node
on one side is dual-homed to two PEs. If a failure occurs in the
primary AC, operators usually prefer to perform switchover only in
the dual-homing PE side and keep the working pseudowire unchanged if
possible. This is to avoid massive PW switchover in the mobile
backhaul network due to the AC failure in the core site, and also
could achieve efficient and balanced link bandwidth utilization.
Similarly, it is preferable to keep using the working AC when one
working PW fails in PSN network. A fast dual-homing PW protection
mechanism is needed to protect the failure in AC, the the PE node and
the PSN network to meet the above requirements.
[I-D.cheng-pwe3-mpls-tp-dual-homing-protection] describes a framework
and several scenarios for dual-homing pseudowire (PW) local
protection. This document proposes a dual-homing coordination
mechanism for static MPLS-TP PWs, which is used for information
exchange and coordination between the dual-homing PEs for the dual-
homing PW local protection. The proposed mechanism has been deployed
in several mobile backhaul networks which use static MPLS-TP PWs for
the backhauling of mobile traffic from the RF sites to the core site.
2. Overview of the Proposed Solution
Linear protection mechanisms for MPLS-TP network are defined in
[RFC6378], [RFC7271] and [RFC7324]. When such mechanisms are applied
to PW linear protection [I-D.shawam-pwe3-ms-pw-protection], both the
working PW and the protection PW are terminated on the same PE nodes.
In order to provide dual-homing protection for MPLS-TP PWs, some
additional mechanisms are needed.
In MPLS-TP PW dual-homing protection, the linear protection mechanism
on the single-homing PE (e.g. PE3 in figure 1) is not changed, while
on the dual-homing side, the working PW and protection PW are
terminated on two dual-homing PEs (e.g. PE1 and PE2 in figure 1)
respectively to protect the failure occurs in the dual-homing PEs and
the connected ACs. As specified in
[I-D.cheng-pwe3-mpls-tp-dual-homing-protection], a dedicated Dual-
Node Interconnection (DNI) PW is provisioned between the two dual-
homing PE nodes, which is used to bridge the traffic between the
dual-homing PEs when failure happens in the working PW or the primary
AC. In order to make the linear protection mechanism work in the
dual-homing PEs scenario, some coordination between the dual-homing
PE nodes is needed, so that the dual-homing PEs can set the
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connection between AC, the service PW and the DNI-PW properly in a
coordinated fashion.
+----------------+
/ | +--------+
AC1 /| PE1 | Working PW | |
/ | X----------------X |
/ | | Service PW1 | |
+---/+ +--------X-------+ | | +----+
| | | DNI PW | PE3 | | |
| CE1| | | |---| CE2|
+---\+ +--------X-------+ | | +----+
\ | | Protection PW | |
\ | X----------------X |
AC2 \| | Service PW2 | |
\ PE2 | +--------+
+----------------+
Figure 1. Dual-homing Proctection with DNI-PW
3. Protocol Extensions for MPLS-TP PW Dual-Homing Protection
In dual-homing MPLS-TP PW local protection, the forwarding state of
the dual-homing PEs are determined by the forwarding state machine as
defined in [I-D.cheng-pwe3-mpls-tp-dual-homing-protection]. In order
to achieve the MPLS-TP PW dual-homing protection, coordination
between the dual-homing PE nodes is needed to exchange the PW status
and protection coordination requests.
3.1. Information Exchange Between Dual-Homing PEs
The coordination information will be sent over the G-ACh as described
in [RFC5586]. A new G-ACh channel type is defined for the
coordination between the dual-homing PEs of MPLS-TP PWs. This
channel type can be used for the exchange of different kinds of
information between the dual-homing PEs. This document uses this
channel type for the PW status exchange and switchover coordination
between the dual-homing PEs. Other potential usage of this channel
type are for further study and are out of the scope of this document.
The MPLS-TP Dual-Homing Coordination (DHC) message is sent on the DNI
PW between the dual-homing PEs. The format of MPLS-TP DHC message is
shown below:
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0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|0 0 0 1|Version| Flags | DHC Code Point |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Dual-Homing PEs Group ID |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| TLV Length | Reserved |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
~ TLVs ~
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 2. MPLS-TP Dual-Homing Coordination Message
The Dual-Homing Group ID is a 4-octet unsigned integer to identify
the dual-homing PEs in the same dual-homing group.
In this document, two TLVs are defined in MPLS-TP Dual-Homing
Coordination message for dual-homing MPLS-TP PW protection:
Type Description Length
1 PW State 20 Bytes
2 Dual-Node Switching 16 Bytes
The PW Status TLV is used by a dual-homing PE to report its service
PW state to the other dual-homing PE in the same dual-homing group.
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 (PW Status) | Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Destination Dual-homing PE Node_ID |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Source Dual-homing PE Node_ID |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| DNI PW-ID |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Flags |P|
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Service PW State |D|F|
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 3. PW State TLV
- The Destination Dual-homing PE Node_ID is the 32-bit Identifier of
the receiver PE.
- The Source Dual-homing PE Node_ID is the 32-bit identifier of the
sending PE.
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- The DNI PW-ID field contains the 32-bit PW-ID of the DNI PW.
- The Flag field contains 32 bit flags.
o The P (Protection) bit indicates whether the Source Dual-homing PE
is the working PE (P=0) or the protection PE (P=1).
o Other bits are reserved for future use.
- The Service PW State field indicates the state of the Service PW
between the sending PE and the remote PE. Currently two bits are
defined in the Service PW Request field:
o F bit: If set, it indicates Signal Fail (SF) is generated on the
service PW. It can be either a local request or a remote request
received from the remote PE.
o D bit: If set, it indicates Signal Degrade (SD) generated on the
service PW. It can be either a local request or a remote request
received from the remote PE.
o Other bits are reserved and MUST be set to 0 on transmission and
SHOULD be ignored upon receipt.
The Dual-Node Switching TLV is used by the protection dual-homing PE
to send protection state coordination to the working dual-homing PE.
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 (Dual-Node Switching) | Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Destination Dual-homing PE Node_ID |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Source Dual-homing PE Node_ID |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| DNI PW-ID |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Flags |S|P|
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 4. Dual-node Switching TLV
- The Destination Dual-homing PE Node_ID is the 32-bit Identifier of
the receiver PE.
- The Source Dual-homing PE Node_ID is the 32-bit identifier of the
sending PE.
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- The DNI PW-ID field contains the 32-bit PW-ID of the DNI PW.
- The Flag field contains 32 bit flags.
o The P (Protection) bit indicates whether the Source Dual-homing PE
is the working PE (P=0) or the protection PE (P=1). With the
mechanism described in this document, only the protection PE can
send DHC message with the Dual-node Switching TLV therefore it is
always set to 1 when sent.
o The S (PW Switching) bit indicates which service PW is used for
forwarding traffic. It is set to 0 when traffic will be
transported on the working PW, and is set to 1 if traffic will be
transported on the protection PW. The value of the S bit is
determined by the protection coordination mechanism between the
dual-homing protection PE and the remote PE.
The MPLS-TP DHC message is exchanged periodically between the dual-
homing PEs. Whenever a change of service PW state is detected by a
dual-homing PE, it MUST be reflected in the PW State TLV and sent to
the other dual-homing PE using a DHC message immediately. The Dual-
Node Switching TLV is carried in the DHC message when a switchover
request is issued by the protection PE according to the linear
protection mechanism.
3.2. Protection Procedures
The dual-homing MPLS-TP PW protection mechanism can be deployed with
the existing AC redundancy mechanisms, e.g. Multi-Chassis Link
Aggregation Group (MC-LAG). On the PSN network side, PSN tunnel
protection mechanism is not required, as the dual-homing PW
protection can also protect the failure occurs in the PSN network.
This section takes one-side dual-homing scenario as example to
describe the dual-homing PW protection procedures, the procedures for
two-side dual-homing scenario would be similar.
On dual-homing PE side, the role of working and protection PE are set
by NMS or local configuration. The service PW connecting to the
working PE is the working PW, and the service PW connecting to the
protection PE is called protection PW.
On single-homing PE side, it just treats the working PW and
protection PW as if they terminate on the same remote PE node, thus
normal MPLS-TP protection coordination mechanisms still apply on the
single-homing PE.
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The forwarding behavior of the dual-homing PEs is determined by the
components shown in the figure below:
+----------------------------------+ +-----+
| PE1 (Working PE) | | |
+----------------------------------+ | |
| | | PW1 | |
+ Forwarder + Service X<--------->X |
/| | PW | Working | |
/ +--------+--------+ | PW | |
AC1 / | DNI PW | | | |
/ +--------X--------+----------------+ | |
+-----+/ ^ | |
| CE1 | | DNI PW | PE3 | +---+
+-----+ | | --|CE3|
\ V | | +---+
AC2 \ +--------X--------+----------------+ | |
\ | DNI PW | | | |
\ +--------+--------+ | | |
\| | Service | PW2 | |
+ Forwarder + PW X<--------->X |
| | | Protection| |
+----------------------------------+ PW | |
| PE2 (Protection PE) | | |
+----------------------------------+ +-----+
Figure 5. Components of one-side dual-homing PW protection
In figure 5, for a dual-homing PE, service PW is the PW used to carry
service between the dual-homing PE and the remote PE. The state of
service PW is determined by some mechanisms between the dual-homing
PE and the remote PE (e.g. by OAM).
DNI PW is provisioned between the two dual-homing PE nodes. It is
used to bridge traffic when failure occurs in the PSN network or in
the ACs. The state of DNI PW is determined by some mechanisms
between the dual-homing PEs (e.g. by OAM). Since DNI PW is used to
carry both the coordination messages and service traffic, it is
RECOMMENDED to provision multiple links between the dual-homing PEs
and use some protection mechanism for the DNI PW.
AC is the link which connects the dual-homing PEs to the dual-homed
CE. The status of AC is determined by some AC redundancy mechanisms
(e.g. by MC-LAG).
In order to perform dual-homing PW local protection, the service PW
state and Dual-node switching coordination requests are exchanged
between the dual-homing PEs using the DHC message defined above.
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Whenever a change of service PW state is detected by a dual-homing
PE, it MUST be reflected in the PW State TLV and sent to the other
dual-homing PE using a DHC message immediately. In case there is a
switchover request received on the protection PW from the remote PE,
the protection PE MUST set the switchover request in the Dual-Node
Switching TLV and send it to the working PE using the DHC message.
After the exchange of service PW state and switching request, both
dual-homing PEs could determine the Active/Standby forwarding status
of the working and protection service PWs. The status of DNI PW and
the ACs are determined by other mechanisms out of the scope of this
document. The forwarding behavior of the dual-homing PE nodes is
determined by the forwarding state machine as shown in the following
table:
+-----------+---------+--------+---------------------+
|Service PW | AC | DNI PW | Forwarding Behavior |
+-----------+---------+--------+---------------------+
| Active | Active | Up |Service PW <-> AC |
+-----------+---------+--------+---------------------+
| Active | Standby | Up |Service PW <-> DNI PW|
+-----------+---------+--------+---------------------+
| Standby | Active | Up | DNI PW <-> AC |
+-----------+---------+--------+---------------------+
| Standby | Standby | Up | Drop all packets |
+-----------+---------+--------+---------------------+
Table 1. Dual-homing PE Forwarding State Machine
Take the topology in figure 5 as example, in normal state, the
working PW (PW1) is in active state, the protection PW (PW2) is in
standby state, the DNI PW is up, and AC1 is in active state according
to AC side redundancy mechanism. According to Table 1, traffic will
be forwarded through the working PW (PW1) and the primary AC (AC1).
No traffic will go through the protection PE (PE2) or the DNI PW, as
both the protection PW (PW2) and the AC connecting to PE2 are in
standby status.
If some failure occurs in AC1, the state of AC2 changes to active
according to the AC redundancy mechanism, while there is no change in
the state of the working and protection PWs. According to the
forwarding state machine in Table 1, PE1 starts to forward traffic
between the working PW and the DNI PW, and PE2 starts to forward
traffic between AC2 and the DNI PW. It should be noted that in this
case only AC switchover takes place, in PSN network traffic is still
fowarded using the working PW.
If some failure in the PSN network causes PW1 to go down, the failure
can be detected by the working PE (PE1) or the remote PE (PE3) using
some mechanisms (e.g. by OAM). If PE1 detects the failure of PW1, it
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MUST inform PE2 the state of working PW using the PW State TLV in DHC
message and change the forwarding status of PW1 to standby. On
receipt of the DHC message, PE2 SHOULD change the forwarding status
of PW2 to active. Then according to the forwarding state machine in
Table 1, PE1 SHOULD set up the connection between the DNI PW and AC1,
and PE2 SHOULD set up the connection between PW2 and the DNI PW.
According to linear protection mechanism, PE2 also sends an
appropriate protection coordination message on the protection PW
(PW2) to PE3 for the remote side switchover from PW1 to PW2. If PE3
detects the failure of PW1, according to linear protection mechanism,
it sends a protection coordination message on the protection PW (PW2)
to inform PE2 to switchover to the protection PW. Upon receipt of
the message, PE2 SHOULD change the forwarding status of PW2 to active
and set up the connection according to Table 1. PE2 SHOULD send a
DHC message to PE1 with the S bit in the Dual-Node Switching TLV set
to coordinate the switchover on PE1 and PE2. This can be useful for
one-direction PW failure which was not detected by PE1.
If some failure causes the working PE (PE1) to go down, the failure
can be detected by both the protection PE(PE2) and the remote PE(PE3)
using some mechanisms (e.g. OAM). PE2 changes the forwarding status
of PW2 to active, and PE3 sends a protection coordination message on
the protection path to inform PE2 to switchover to the protection PW.
According to AC redundancy mechanism, the status of AC1 changes to
standby, and the state of AC2 changes to active. According to the
forwarding state machine in Table 1, PE2 starts to forward traffic
between the protection PW and AC2.
4. IANA Considerations
IANA needs to assign one new channel type for "MPLS-TP Dual-Homing
Coordination messgae" from the "Pseudowire Associated Channel Types"
registry.
This document creates a new registry called "MPLS-TP DHC TLVs"
registry. Two new TLVs are defined in this document:
Type Description Length
1 PW Status 20 Bytes
2 Dual-Node Switching 16 Bytes
5. Security Considerations
Procedures and protocol extensions defined in this document do not
affect the security model of MPLS-TP linear protection as defined in
[RFC6378]. Please refer to [RFC5920] for MPLS security issues and
generic methods for securing traffic privacy and integrity.
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6. References
6.1. Normative References
[I-D.cheng-pwe3-mpls-tp-dual-homing-protection]
Cheng, W., Wang, L., Li, H., Liu, K., Davari, S., Dong,
J., and A. D'Alessandro, "Dual-Homing Protection for MPLS
and MPLS-TP Pseudowires", draft-cheng-pwe3-mpls-tp-dual-
homing-protection-01 (work in progress), October 2014.
[I-D.shawam-pwe3-ms-pw-protection]
Malis, A., Andersson, L., Helvoort, H., Shin, J., Wang,
L., and A. D'Alessandro, "S-PE Outage Protection for
Static Multi-Segment Pseudowires", draft-shawam-pwe3-ms-
pw-protection-02 (work in progress), October 2014.
[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
Requirement Levels", BCP 14, RFC 2119, March 1997.
[RFC5586] Bocci, M., Vigoureux, M., and S. Bryant, "MPLS Generic
Associated Channel", RFC 5586, June 2009.
[RFC6372] Sprecher, N. and A. Farrel, "MPLS Transport Profile (MPLS-
TP) Survivability Framework", RFC 6372, September 2011.
[RFC6378] Weingarten, Y., Bryant, S., Osborne, E., Sprecher, N., and
A. Fulignoli, "MPLS Transport Profile (MPLS-TP) Linear
Protection", RFC 6378, October 2011.
[RFC7271] Ryoo, J., Gray, E., van Helvoort, H., D'Alessandro, A.,
Cheung, T., and E. Osborne, "MPLS Transport Profile (MPLS-
TP) Linear Protection to Match the Operational
Expectations of Synchronous Digital Hierarchy, Optical
Transport Network, and Ethernet Transport Network
Operators", RFC 7271, June 2014.
[RFC7324] Osborne, E., "Updates to MPLS Transport Profile Linear
Protection", RFC 7324, July 2014.
6.2. Informative References
[I-D.ietf-pwe3-endpoint-fast-protection]
Shen, Y., Aggarwal, R., Henderickx, W., and Y. Jiang, "PW
Endpoint Fast Failure Protection", draft-ietf-pwe3-
endpoint-fast-protection-01 (work in progress), July 2014.
[RFC5920] Fang, L., "Security Framework for MPLS and GMPLS
Networks", RFC 5920, July 2010.
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[RFC6718] Muley, P., Aissaoui, M., and M. Bocci, "Pseudowire
Redundancy", RFC 6718, August 2012.
[RFC6870] Muley, P. and M. Aissaoui, "Pseudowire Preferential
Forwarding Status Bit", RFC 6870, February 2013.
Authors' Addresses
Weiqiang Cheng
China Mobile
No.32 Xuanwumen West Street
Beijing 100053
China
Email: chengweiqiang@chinamobile.com
Lei Wang
China Mobile
No.32 Xuanwumen West Street
Beijing 100053
China
Email: Wangleiyj@chinamobile.com
Han Li
China Mobile
No.32 Xuanwumen West Street
Beijing 100053
China
Email: Lihan@chinamobile.com
Kai Liu
Huawei Technologies
Huawei Base, Bantian, Longgang District
Shenzhen 518129
China
Email: alex.liukai@huawei.com
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Shahram Davari
Broadcom Corporation
3151 Zanker Road
San Jose 95134-1933
United States
Email: davari@broadcom.com
Jie Dong
Huawei Technologies
Huawei Campus, No. 156 Beiqing Rd.
Beijing 100095
China
Email: jie.dong@huawei.com
Alessandro D'Alessandro
Telecom Italia
via Reiss Romoli, 274
Torino 10148
Italy
Email: alessandro.dalessandro@telecomitalia.it
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