Network Working Group W. Cheng
Internet-Draft L. Wang
Intended status: Standards Track H. Li
Expires: December 17, 2016 China Mobile
K. Liu
Huawei Technologies
S. Davari
Broadcom Corporation
J. Dong
Huawei Technologies
A. D'Alessandro
Telecom Italia
June 15, 2016
Dual-Homing Coordination for MPLS Transport Profile (MPLS-TP)
Pseudowires Protection
draft-ietf-pals-mpls-tp-dual-homing-coordination-03
Abstract
In some scenarios, the MPLS Transport 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 typical scenarios of dual-homing PW
local protection are described in [draft-ietf-pals-mpls-tp-dual-
homing-protection]. This document proposes a dual-homing
coordination mechanism for MPLS-TP PWs, which is used for state
exchange and switchover 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 December 17, 2016.
Copyright Notice
Copyright (c) 2016 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 Dual-Homing MPLS-TP PW Protection . . 4
3.1. Information Exchange Between Dual-Homing PEs . . . . . . 4
3.2. Protection Procedures . . . . . . . . . . . . . . . . . . 7
4. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 10
5. Security Considerations . . . . . . . . . . . . . . . . . . . 11
6. References . . . . . . . . . . . . . . . . . . . . . . . . . 11
6.1. Normative References . . . . . . . . . . . . . . . . . . 11
6.2. Informative References . . . . . . . . . . . . . . . . . 11
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 12
1. Introduction
[RFC6372], [RFC6378] and [RFC7771] 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 Attachment 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 PW switchover in case
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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 PE node and the
PSN network to meet the above requirements.
[I-D.ietf-pals-mpls-tp-dual-homing-protection] describes a framework
and several scenarios of 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 switchover 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 radio access 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 [RFC7771], 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.ietf-pals-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 connection between
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the 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 Protection with DNI-PW
3. Protocol Extensions for Dual-Homing MPLS-TP PW 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.ietf-pals-mpls-tp-dual-homing-protection]. In order
to achieve the dual-homing MPLS-TP PW 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 exchange of PW status 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, in which:
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 one dual-homing PE to send
protection state coordination to the other 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, in which:
o The P (Protection) bit indicates whether the Source Dual-homing PE
is the working PE or the protection PE. it is set to 1 when the
Source PE of the dual-node switching request is the protection PE.
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 PEs 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 immediately using a DHC message.
When one dual-homing PE determines that the active service PW SHOULD
be switched from the working PW to the protection PW, the Dual-Node
Switching TLV MUST be sent to the other dual-homing PE immediately
using a DHC message.
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 occured 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 the 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 each 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 PEs 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 immediately using a DHC message. This ensures that
both dual-homing PEs have the state of the working and protection PW.
When there is a switchover request either generated locally or
received on the protection PW from the remote PE, based on the status
of the working and protection service PW, along with the local and
remote request of the protection coordination between the dual-homing
PEs and the remote PE, the active/standby state of the service PW can
be determined by the dual-homing PEs. As the remote protection
coordination request is transmitted over the protection path, in this
case the active/standby state of service PW is determined by the
protection PE.
If it is determined on one dual-homing PE that switchover of service
PW is needed, this dual-homing PE MUST set the S bit in the Dual-Node
Switching TLV and send it to the other dual-homing PE immediately
using a DHC message. With the exchange of service PW state and the
switching request, both dual-homing PEs are consistent on the Active/
Standby forwarding status of the working and protection service PWs.
The status of DNI PW and the ACs are determined by some mechanisms
out of the scope of this document. The forwarding behavior on 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.
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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
forwarded using the working PW.
If some failure in the PSN network brings PW1 to down, the failure
can be detected by PE1 or PE3 using some mechanisms (e.g. by OAM).
If PE1 detects the failure of PW1, it 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 over the protection PW (PW2) to PE3 for the
remote side to 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 of the failure on the working 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
unidirectional failure which was not detected by PE1.
If some failure brings the working PE (PE1) to down, the failure can
be detected by both PE2 and PE3 using some mechanisms (e.g. OAM).
Both PE2 and PE3 SHOULD change the forwarding status of PW2 to
active, and send a protection coordination message on the protection
PW (PW2) to inform the remote side to switchover. 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 PW2 and
AC2.
4. IANA Considerations
IANA needs to assign one new channel type for "MPLS-TP Dual-Homing
Coordination message" 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:
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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.
6. References
6.1. Normative References
[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>.
[RFC5586] Bocci, M., Ed., Vigoureux, M., Ed., and S. Bryant, Ed.,
"MPLS Generic Associated Channel", RFC 5586,
DOI 10.17487/RFC5586, June 2009,
<http://www.rfc-editor.org/info/rfc5586>.
[RFC6378] Weingarten, Y., Ed., Bryant, S., Osborne, E., Sprecher,
N., and A. Fulignoli, Ed., "MPLS Transport Profile (MPLS-
TP) Linear Protection", RFC 6378, DOI 10.17487/RFC6378,
October 2011, <http://www.rfc-editor.org/info/rfc6378>.
[RFC7271] Ryoo, J., Ed., Gray, E., Ed., 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, DOI 10.17487/RFC7271, June 2014,
<http://www.rfc-editor.org/info/rfc7271>.
[RFC7324] Osborne, E., "Updates to MPLS Transport Profile Linear
Protection", RFC 7324, DOI 10.17487/RFC7324, July 2014,
<http://www.rfc-editor.org/info/rfc7324>.
6.2. Informative References
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[I-D.ietf-pals-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-ietf-pals-mpls-tp-dual-
homing-protection-02 (work in progress), March 2016.
[RFC5920] Fang, L., Ed., "Security Framework for MPLS and GMPLS
Networks", RFC 5920, DOI 10.17487/RFC5920, July 2010,
<http://www.rfc-editor.org/info/rfc5920>.
[RFC6372] Sprecher, N., Ed. and A. Farrel, Ed., "MPLS Transport
Profile (MPLS-TP) Survivability Framework", RFC 6372,
DOI 10.17487/RFC6372, September 2011,
<http://www.rfc-editor.org/info/rfc6372>.
[RFC6718] Muley, P., Aissaoui, M., and M. Bocci, "Pseudowire
Redundancy", RFC 6718, DOI 10.17487/RFC6718, August 2012,
<http://www.rfc-editor.org/info/rfc6718>.
[RFC6870] Muley, P., Ed. and M. Aissaoui, Ed., "Pseudowire
Preferential Forwarding Status Bit", RFC 6870,
DOI 10.17487/RFC6870, February 2013,
<http://www.rfc-editor.org/info/rfc6870>.
[RFC7771] Malis, A., Ed., Andersson, L., van Helvoort, H., Shin, J.,
Wang, L., and A. D'Alessandro, "Switching Provider Edge
(S-PE) Protection for MPLS and MPLS Transport Profile
(MPLS-TP) Static Multi-Segment Pseudowires", RFC 7771,
DOI 10.17487/RFC7771, January 2016,
<http://www.rfc-editor.org/info/rfc7771>.
Authors' Addresses
Weiqiang Cheng
China Mobile
No.32 Xuanwumen West Street
Beijing 100053
China
Email: chengweiqiang@chinamobile.com
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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
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
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Alessandro D'Alessandro
Telecom Italia
via Reiss Romoli, 274
Torino 10148
Italy
Email: alessandro.dalessandro@telecomitalia.it
Cheng, et al. Expires December 17, 2016 [Page 14]
