Internet Working Group Y. Jiang
L. Yong
Internet Draft Huawei
M. Paul
Deutsche Telekom
Intended status: Standards Track F. Jounay
France Telecom Orange
Expires: April 2011 October 25, 2010
VPLS PE Model for E-Tree Support
draft-jiang-l2vpn-vpls-pe-etree-02.txt
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Abstract
A generic VPLS solution for E-Tree services is proposed which uses
VLANs to indicate root/leaf traffic. A VPLS Provider Edge (PE) model
is illustrated as an example for the solution. In the solution, E-
Tree VPLS PEs are interconnected by full mesh tagged PWs, the MAC
address based Ethernet forwarding engine and the PW works in the same
way as before. A signaling mechanism for E-Tree capability and VLAN
mapping notification is further described.
Table of Contents
1. Introduction................................................2
2. Conventions used in this document...........................4
3. Terminology.................................................4
4. PE Model with E-Tree Support................................4
4.1. Existing PE Models.......................................4
4.2. A New PE Model with E-Tree Support.......................7
5. PW for E-Tree Support.......................................8
5.1. VLAN Mapping.............................................8
5.2. Tagged Mode PW Encapsulation.............................9
5.3. PW Processing...........................................10
5.3.1. PW Processing in the Normal Mode..................10
5.3.2. PW Processing in the Compatibility Mode...........11
5.3.3. PW Processing in the Optimization Mode............12
6. LDP Extensions for E-Tree Support..........................13
7. BGP Extensions for E-Tree Support..........................14
8. Applicability..............................................14
9. Security Considerations....................................14
10. IANA Considerations........................................14
11. References.................................................15
11.1. Normative References.................................15
11.2. Informative References...............................15
12. Acknowledgments............................................16
Appendix A. Other PE Models for E-Tree...........................17
A.1. PE Model With a VSI and No bridge........................17
1. Introduction
E-Tree service is defined in Metro Ethernet Forum (MEF) as rooted
multi-point EVC service, where traffic from a root can reach any root
or leaf, and traffic from a leaf can reach any root, but should never
reach a leaf. Although VPMS or P2MP multicast is a somewhat
simplified version of this service, in fact there is no exact
corresponding terminology in IETF.
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[Etree-req] gives the requirements to provide E-Tree solutions in the
VPLS and the need to filter leaf to leaf traffic in the VPLS.
[vpls-etree] describes a PW control word based E-Tree solution, where
a bit in the PW control word is used to indicate the root/leaf
attribute for a packet. The Ethernet forwarder in the VPLS is also
extended to filter the leaf-leaf traffic based on the <ingress port,
egress port, CW L-bit> tuple.
[Etree-2PW] proposes another E-Tree solution where root and leaf
traffic are classified and forwarded in the same VSI but with two
separate PWs.
Both solutions are only applicable to "VPLS only" networks.
In fact, VPLS PE usually consists of a bridge module itself [RFC4664],
moreover E-Tree services may cross both Ethernet and VPLS domains.
Therefore, the support of interconnection between Ethernet and VPLS
for an E-Tree service is indispensable.
IEEE 802.1 has incorporated the generic E-Tree solution in the latest
version of 802.1Q [802.1aq], which is just an improvement on the
traditional asymmetric VLAN mechanism. In the solution, VLANs are
used to indicate root/leaf attribute of a packet: one VLAN is used to
carry traffic originated from the roots and another VLAN is used to
carry traffic originated from the leaves. The bridge can then filter
on each leaf port all the traffic received on the VLANs associated
with the leaves. Thus it is better to use the same mechanism in VPLS
rather than develop a new mechanism which may not interwork with
Ethernet.
This document introduces how the Ethernet VLAN solution can be used
to support generic E-Tree services in the VPLS. This solution is
fully compatible with the IEEE bridge architecture and the IETF PWE3
technology, and VPLS scalability and simplicity is also well kept.
With this mechanism it is also possible to deploy a converged E-Tree
service across both Ethernet and MPLS networks.
As an example, a typical VPLS PE model is firstly introduced and
extended which consists of a Tree VSI connected to an S-VLAN bridge
with a dual-VLAN interface. However, this model is applicable to a PE
with C-VLAN or B-VLAN as its service demarcation's encapsulation.
This document then discusses the PW encapsulation and PW processing
such as VLAN mapping options for transporting E-Tree services in a
VPLS.
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Finally, the extensions needed to support the signaling of E-Tree
capability and VLAN mapping are also discussed.
2. Conventions used in this document
The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
"SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this
document are to be interpreted as described in [RFC2119].
3. Terminology
Most of the terminology used here is from [IEEE802.1Q], [IEEE802.1ad],
[RFC4664] and [RFC4762]. Terminology specific to this document is
introduced as needed in later sections.
4. PE Model with E-Tree Support
"VPLS only" PE architecture as outlined in Fig. 1 of [Etree-req] is a
simplification of the PWE3 architecture, the more common VPLS PE
architectures are discussed in more details in [RFC 4664] and [vpls-
interop].
Therefore, VLAN based E-Tree solution are demonstrated with the help
of a typical VPLS PE model. Other PE models are further discussed in
Appendix A.
4.1. Existing PE Models
According to [RFC4664], there are at least three models possible for
a VPLS PE, including:
o A single bridge module, a single VSI;
o A single bridge module, multiple VSIs;
o Multiple bridge modules, each attaches to a VSI.
The second PE model as depicted in Fig. 1 and Fig. 2 is a typical one
for VPLS [vpls-interop], where the S-VLAN bridge module is connected
to multiple VSIs each with a single VLAN interface.
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+-------------------------------+
| 802.1ad Bridge Module Model |
| |
+---+ | +------+ +-----------+ |
|CE |---------|C-VLAN|------| | |
+---+ | |bridge|------| | |
| +------+ | | |
| o | S-VLAN | |
| o | | |
| o | Bridge | |
+---+ | +------+ | | |
|CE |---------|C-VLAN|------| | |
+---+ | |bridge|------| | |
| +------+ +-----------+ |
+-------------------------------+
Figure 1 The Model of 802.1ad Bridge Module
+----------------------------------------+
| VPLS-capable PE model |
| +---------------+ +------+ |
| | | |VSI-1 |------------
| | |==========| |------------ PWs
| | Bridge ------------ |------------
| | | S-VLAN-1 +------+ |
| | Module | o |
| | | o |
| | (802.1ad | o |
| | bridge) | o |
| | | o |
| | | S-VLAN-n +------+ |
| | ------------VSI-n |-------------
| | |==========| |------------- PWs
| | | ^ | |-------------
| +---------------+ | +------+ |
| | |
+-------------------------|--------------+
LAN emulation Interface
Figure 2 VPLS-capable PE Model
In the PE model above, Ethernet service from the CEs will cross
multiple stages of bridge modules (i.e., C-VLAN and S-VLAN bridge) in
a PE to access the egress PWs. Therefore, the association of an AC
port and a PW in a single forwarding engine as required in [vpls-
etree] or [Etree-2PW] is difficult, sometimes even impossible.
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This model could be further enhanced by the introduction of a trunk
VLAN and a branch VLAN as Ethernet frames enter the PE. To be more
precise, they are called root and leaf VLAN respectively in this
document. All the traffics from the root VLAN are received both on
the roots and the leaves, while traffics from the branch VLAN are
received on the roots and dropped on the leaves. It was demonstrated
in [802.1aq] that E-Tree on Ethernet could be well supported with
this mechanism.
Assume this mechanism is implemented in the bridge module, then it is
quite straightforward to infer a VPLS PE model with two VSIs (as
shown in Fig. 3) to support the E-Tree. But this model will require
two VSIs per PE and two sets of full meshed PWs per E-Tree service,
which is poorly scalable in a large MPLS/VPLS network.
+----------------------------------------+
| VPLS-capable PE model |
| +---------------+ +------+ |
| | | |VSI-1 |------------
| | |==========| |------------ PWs
| | Bridge ------------ |------------
| | | Root +------+ |
| | Module | S-VLAN o |
| | | o |
| | (802.1ad | o |
| | bridge) | o |
| | | Leaf o |
| | | S-VLAN +------+ |
| | ------------VSI-2 |-------------
| | |==========| |------------- PWs
| | | ^ | |-------------
| +---------------+ | +------+ |
| | |
+-------------------------|--------------+
LAN emulation Interface
Figure 3 VPLS PE Model with E-Tree Support
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4.2. A New PE Model with E-Tree Support
To provide for the E-Tree support in a more scalable way, a new VPLS
PE model is proposed and depicted in Fig. 4, where the S-VLAN bridge
module is connected to the Tree VSI (T-VSI, a VSI with E-Tree support)
with a dual-VLAN virtual interface. That is, both the root S-VLAN and
the leaf S-VLAN are connected to the Tree VSI (T-VSI). In this way,
only one VPLS instance and one set of PWs is needed per E-Tree
service. With this model, multiple E-Trees can also be provided by
the same T-VSI if needed, and further increase the scalability of
VPLS.
+----------------------------------------+
| VPLS-capable PE model |
| +---------------+ +------+ |
| | |==========|TVSI-1|------------
| | ------------ |------------ PWs
| | Bridge ------------ |------------
| | | Root & +------+ |
| | Module | Leaf VLAN o |
| | | o |
| | (802.1ad | o |
| | bridge) | o |
| | | o |
| | | S-VLAN-n +------+ |
| | ------------VSI-n |-------------
| | |==========| |------------- PWs
| | | ^ | |-------------
| +---------------+ | +------+ |
| | |
+-------------------------|--------------+
LAN emulation Interface
Figure 4 E-Tree VPLS-capable PE Model
Both VLANs should share the same FIB and work in shared VLAN learning.
The traffic from the root UNIs are firstly tagged with root C-VLAN by
the C-VLAN bridge module, and then tagged with root S-VLAN by the S-
VLAN bridge module, thus can only be transported on the root S-VLAN.
Similarly, the traffic from the leaves can only be transported on the
leaf S-VLAN.
In fact, this model can also be applied to a PE with C-VLAN (customer
sites attached to the PEs with untagged ports), or B-VLAN (with a PBB
bridge module embedded in the PE) as a provider's tag encapsulation.
Therefore, the document will use the VLAN tag as a generalized form
in the latter sections.
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5. PW for E-Tree Support
A pair of T-VSIs in a VPLS is interconnected with a bidirectional PW.
The VLAN indicating root/leaf attribute of the packet is carried in
the PW, and the peer PE must drop the packet with a leaf VLAN on the
egress AC of leaf UNI.
There are three ways of manipulating VLANs for an E-Tree:
o Provisioning two global VLANs across both the Ethernet and the
VPLS instance domain;
o Provisioning two local VLANs in the VLAN space for each Ethernet
domain and two global VLANs in the VPLS network domain, the VLAN
mapping is done completely in the Ethernet domains (e.g., in the
bridge module of the PE).
o Provisioning two local VLANs independently for each Ethernet
domain and two local VLANs on each PE for better scalability. That
is, the assignment of VLANs in the PE may be local to improve the
scalability.
The first method is called global VLAN based and no VLAN mapping is
needed, but two unique VLANs must be allocated in the VPLS for them.
The second method is called partial global VLAN based, which needs a
VLAN mapping in the bridge module or in the Ethernet device attached
to the PE. The last method is called local VLAN based and more
scalable, but needs a VLAN mechanism in the PW. VLAN mapping is
elaborated in the following section.
5.1. VLAN Mapping
In order to carry both VLANs (root and leaf VLAN) in a single PW and
map those into the remote peer's VLANs, cares must be taken on both
the PEs associated with the PW.
Two options of VLAN mapping are possible:
o Local mapping, that is, the remote PE is responsible for mapping
VLANs into its local VLANs. For the local VLAN based method, VLAN
mapping is done when a frame exits the PW; for the partial global
VLAN based method, VLAN mapping is done when a frame exits the
bridge module.
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o Remote mapping, that is, the local PE is responsible for mapping
VLANs into the remote PE's VLANs. For the local VLAN based method,
VLAN mapping is done when a frame enters the PW; for the partial
global VLAN based method, VLAN mapping is done when a frame enters
the bridge module.
Normally, each PE does its own local mapping. But when a PE is not
capable of VLAN mapping, remote mapping can be done on its peer.
If no PE is capable of VLAN mapping, global VLAN based method can be
used instead.
5.2. Tagged Mode PW Encapsulation
For a VPLS instance to support an E-Tree as described above, the
Ethernet PW should work in the tagged mode (PW type 0x0004) as
described in [RFC4448], and a C-VLAN, S-VLAN, or B-VLAN tag must be
carried in each frame in the PW to indicate the E-Tree root/leaf
attribute.
For global VLAN based method, it is the global VLAN tag to be carried
and no VLAN mapping needed in the VPLS.
For the local VLAN or partial global VLAN based method, either the
local or the remote VLAN tag could be carried depending on the
mapping option. In the local mapping mode, the remote VLANs are
carried with no change, while in the remote mapping mode, the local
VLANs are carried instead.
The mapping between the local VLAN and the remote VLAN (local root
VLAN <-> remote root VLAN; local leaf VLAN <-> remote leaf VLAN)
should be provisioned by management or signaled by a control protocol
such as LDP. The signaling extensions for E-Tree support are provided
in Section 6 and 7.
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5.3. PW Processing
5.3.1.PW Processing in the Normal Mode
In the normal mode, two VPLS PEs with a T-VSI in each of them are
inter-connected and both sides are miscellaneously attached with
roots and leaves, as shown in the scenario of Fig. 5. At the PE where
a frame exits the PW, if a frame with the remote leaf VLAN is
received, then it is mapped to the local leaf VLAN, otherwise, if a
frame with the remote root VLAN is received, then it is mapped to the
local root VLAN. Packets over both VLANs are processed in the same I-
VSI and are further forwarded or dropped in the exit bridge module
using the mechanism as described in 802.1Q.
+--------------------------------+
| VPLS PE with T-VSI |
| |
+----+ | +------+ +-------+ +-----+ | PW
|Root|------|C-VLAN|---|S-VLAN |---|T-VSI|----------
+----+ | | BRG | | BRG | | |----------
+----+ | | |---| |---| |----------
|Leaf|------| | | | | |---------+
+----+ | +------+ +-------| +-----+ | |
| | |
+--------------------------------+ |
|
+--------------------------------+ |
| VPLS PE with T-VSI | |
| | |
+----+ | +------+ +-------+ +-----+ | PW |
|Root|------|C-VLAN|---|S-VLAN |---|T-VSI|---------+
+----+ | | BRG | | BRG | | |----------
+----+ | | |---| |---| |----------
|Leaf|------| | | | | |----------
+----+ | +------+ +-------| +-----+ |
| |
+--------------------------------+
Figure 5 T-VSI Interconnected in the Normal Mode
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5.3.2.PW Processing in the Compatibility Mode
The new VPLS PE model can work in a traditional VPLS network
seamlessly in the compatibility mode. As shown in Fig. 5, the VPLS PE
with T-VSI can access both root and leaf node, while the VPLS PE with
a traditional VSI can only access the root node.
+--------------------------------+
| VPLS PE with T-VSI |
| |
+----+ | +------+ +-------+ +-----+ | PW
|Root|------|C-VLAN|---|S-VLAN |---|T-VSI|----------
+----+ | | BRG | | BRG | | |----------
+----+ | | |---| |---| |----------
|Leaf|------| | | | | |---------+
+----+ | +------+ +-------| +-----+ | |
| | |
+--------------------------------+ |
|
+--------------------------------+ |
| VPLS PE with VSI | |
| | |
+----+ | +------+ +-------+ +-----+ | PW |
|Root|------|C-VLAN|---|S-VLAN |---|VSI |---------+
+----+ | | BRG | | BRG | | |----------
+----+ | | |---| | | |----------
|Root|------| | | | | |----------
+----+ | +------+ +-------| +-----+ |
| |
+--------------------------------+
Figure 6 T-VSI interconnected with Traditional VSI
In this case, the PE with a T-VSI in it must work in the
compatibility mode, that is, the egress PW of the T-VSI must
translate frames received over both local root and leaf VLAN into a
PW with a single VLAN (i.e., local root VLAN if the peer is capable
of rewriting the VLAN, or the remote peer's VLAN otherwise), while
the ingress PW only translates the frames received over the PW into
the local root VLAN.
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5.3.3.PW Processing in the Optimization Mode
When two VPLS PE with T-VSI are inter-connected and one side is
attached with pure leaves, as shown in the scenario of Fig. 6, the
egress PW of the miscellaneous attached PE then should work in the
optimization mode, that is, the PE can drop all the frames received
over the local leaf VLAN rather than transport them over the PW and
be discarded on the remote PE. Thus bandwidth efficiency of the VPLS
can be improved.
+--------------------------------+
| VPLS PE with T-VSI |
| |
+----+ | +------+ +-------+ +-----+ | PW
|Root|------|C-VLAN|---|S-VLAN |---|T-VSI|----------
+----+ | | BRG | | BRG | | |----------
+----+ | | |---| |---| |----------
|Leaf|------| | | | | |---------+
+----+ | +------+ +-------| +-----+ | |
| | |
+--------------------------------+ |
|
+--------------------------------+ |
| VPLS PE with T-VSI | |
| | |
+----+ | +------+ +-------+ +-----+ | PW |
|Leaf|------|C-VLAN|---|S-VLAN |---|T-VSI|---------+
+----+ | | BRG | | BRG | | |----------
+----+ | | |---| |---| |----------
|Leaf|------| | | | | |----------
+----+ | +------+ +-------| +-----+ |
| |
+--------------------------------+
Figure 7 T-VSI interconnected with 1-side of pure Leaves
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6. LDP Extensions for E-Tree Support
To dynamically provision the E-Tree service using the signaling
procedures specified in [RFC4447], an E-Tree specific interface
parameter sub-TLV is proposed 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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| E-Tree | Length=8 | Reserved |P|R|
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Root VLAN ID | Leaf VLAN ID |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 8 E-Tree Sub-TLV
Where:
o E-Tree is the sub-TLV identifier to be assigned by IANA.
o Length is the length of the sub TLV in octets.
o Reserved bits MUST be set to zero on transmit and be ignored on
receive.
o P is a Pure Leaf bit, it is set to 1 to indicate that the PE is
attached with all leaves, and set to 0 otherwise.
o R is a request bit of Remote VLAN Translation. If a PE is capable
of translating VLANs, then set R to 0, otherwise set R to 1. If a
PE receives R=1 from its peer, then it must do VLAN translation
for this peer, otherwise local mapping rule applies.
o Root VLAN ID is the value of the local root VLAN.
o Leaf VLAN ID is the value of the local leaf VLAN.
When the VPLS supporting an E-Tree service is setting up the PW, the
PW endpoints negotiate the E-Tree support using the above E-Tree sub-
TLV. Note PW type of 0x0004 should be used during the PW negotiation.
A PE that wishes to support E-Tree service includes an E-Tree Sub-TLV
in its PW label mapping message, together with its local root VLAN
and leaf VLAN carried in the Root VLAN ID and Leaf VLAN ID field
respectively. A PE that has E-Tree capability and willing to support
it MUST include an E-Tree Sub-TLV with its own local root VLAN and
leaf VLAN. A PE that is incapable of translating VLANs MUST set the R
bit to 1, while a PE that is capable of translating VLANs MAY set the
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R bit to 1 to indicate remote mapping is preferred. And a PE is
attached with pure leaves SHOULD set the P bit to 1.
If a PE incapable of VLAN mapping has received an E-Tree Sub-TLV with
the bit "R" set, and either the root VLAN ID or the leaf VLAN ID in
the message does not match the local root VLAN or the local leaf VLAN,
then the PW should not be set up and a label release message with the
error code "E-Tree VLAN mapping not supported" must be sent.
If a PE has sent an E-Tree Sub-TLV and has received an E-Tree Sub-TLV,
then it must work as described in Section 5.3.1. If the bit "L" is
set, then it should work as described in Section 5.3.3.
If a PE has sent an E-Tree Sub-TLV and does not receive an E-Tree
Sub-TLV, then it must work in the mode of compatibility as described
in Section 5.3.2.
7. BGP Extensions for E-Tree Support
BGP may also be used to distribute the E-Tree and VLAN mapping
information. It is to be specified in the next version.
8. Applicability
The solution is applicable to LDP VPLS [RFC4762] and may also be
applicable to BGP VPLS [RFC 4761].
The solution is applicable to both "VPLS Only" network and VPLS with
Ethernet aggregation network.
9. Security Considerations
To be added in the next version.
10. IANA Considerations
IANA is requested to allocate a value for E-Tree in the Pseudowire
Interface Parameters Sub-TLV type registry.
Parameter ID Length Description
=======================================
TBD 8 E-Tree
IANA is requested to allocate a new LDP status code from the registry
of name "STATUS CODE NAME SPACE". The following value is suggested:
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Range/Value E Description
------------- ----- ----------------------
TBD 0 E-Tree VLAN mapping not supported
11. References
11.1. Normative References
[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
Requirement Levels", BCP 14, RFC 2119, March 1997.
[RFC4447] Martini, L., and et al, "Pseudowire Setup and Maintenance
Using Label Distribution Protocol (LDP)", RFC 4447, April
2006.
[RFC4448] Martini, L., and et al, "Encapsulation Methods for
Transport of Ethernet over MPLS Networks", RFC 4448, April
2006.
[RFC4762] Lasserre, M. and Kompella, V., "Virtual Private LAN
Services using LDP", RFC 4762, January 2007.
11.2. Informative References
[RFC3985] Bryant, S., and Pate, P., "Pseudo Wire Emulation Edge-to-
Edge (PWE3) Architecture", RFC 3985, March 2005.
[RFC4664] Andersson, L., and Rosen, E., "Framework for Layer 2
Virtual Private Networks (L2VPNs)", RFC 4664, September
2006.
[vpls-interop] Sajassi, A., and et al, "VPLS Interoperability with CE
Bridges", draft-ietf-l2vpn-vpls-bridge-interop-05, March
2010
[ETree-req] Key, R., et al, "Requirements for MEF E-Tree Support in
VPLS", draft-key-l2vpn-vpls-etree-reqt-02, October 2010
[vpls-etree] Delord, S., and et al, "Extension to VPLS for E-Tree",
draft-key-l2vpn-vpls-etree-02, January 2010
[802.1aq] IEEE 802.1aq D3.0, Virtual Bridged Local Area Networks -
Amendment 9: Shortest Path Bridging, June 2010
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[Etree-2PW] Ram, R., and et al., Extension to LDP-VPLS for E-Tree
Using Two PW, draft-ram-l2vpn-ldp-vpls-etree-2pw-00.txt,
October 2010
12. Acknowledgments
The authors would like to thank Adrian Farrel and Susan Hares for
their valuable comments and advices.
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Appendix A. Other PE Models for E-Tree
A.1. PE Model With a VSI and No bridge
If there is no bridge module in a PE, the PE may consist of Native
Service Processors (NSPs) as shown in Figure A.1 (adapted from Fig. 5
of [RFC3985]) which may apply any transformation operation for VLANs
(e.g., VLAN insertion/removal or VLAN mapping). Thus a root VLAN or
leaf VLAN is added by the NSP depending on the UNI type of the AC
over which the packet arrives.
Further, when a packet with a leaf VLAN exits a forwarder and arrives
at the NSP, the NSP must drop the packet if the egress AC is a leaf
UNI.
Tagged PW and VLAN mapping work in the same way as in the typical PE
model.
+----------------------------------------+
| PE Device |
Multiple+----------------------------------------+
AC | | | Single | PW Instance
<------>o NSP # + PW Instance X<---------->
| | | |
|------| VSI |----------------------|
| | | Single | PW Instance
<------>o NSP #Forwarder + PW Instance X<---------->
| | | |
|------| |----------------------|
| | | Single | PW Instance
<------>o NSP # + PW Instance X<---------->
| | | |
+----------------------------------------+
Figure A.1 PE model with a VSI and no bridge module
Jiang, et al Expires April 25, 2011 [Page 17]
Internet-Draft VPLS PE Model for E-Tree October 2010
Authors' Addresses
Yuanlong Jiang
Huawei Technologies Co., Ltd.
Bantian industry base, Longgang district
Shenzhen, China
Email: yljiang@huawei.com
Lucy Yong
Huawei USA
1700 Alma Dr. Suite 500
Plano, TX 75075, USA
Email: lucyyong@huawei.com
Manuel Paul
Deutsche Telekom
Goslarer Ufer 35
10589 Berlin, Germany
Email: manuel.paul@telekom.de
Frederic Jounay
France Telecom Orange
2, avenue Pierre-Marzin
22307 Lannion Cedex, France
Email: frederic.jounay@orange-ftgroup.com
Jiang, et al Expires April 25, 2011 [Page 18]