One document matched: draft-li-ccamp-role-based-automesh-01.txt
Differences from draft-li-ccamp-role-based-automesh-00.txt
Network Working Group Z. Li
Internet-Draft M. Chen
Intended status: Standards Track Huawei
Expires: April 17, 2014 October 14, 2013
Routing Extensions for Discovery of Role-based MPLS Label Switching
Router (MPLS LSR) Traffic Engineering (TE) Mesh Membership
draft-li-ccamp-role-based-automesh-01
Abstract
A Traffic Engnieering (TE) mesh-group is defined as a group of Label
Switch Routers (LSRs) that are connected by a full mesh of TE LSPs.
Routing (OSPF and IS-IS) extensions for discovery Multiprotocol Label
Switching (MPLS) LSR TE mesh membership has been defined to automate
the creation of mesh of TE LSPs.
This document introduces a role-based TE mesh-group that applies to
the scenarios where full mesh TE LSPs are not necessary and TE LSPs
setup depends on the roles of LSRs in a TE mesh-group. Interior
Gateway Protocol (IGP) routing extensions for automatic discovery of
role-based TE mesh membership are defined accordingly.
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
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 April 17, 2014.
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Copyright Notice
Copyright (c) 2013 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. Role-based TE Mesh Group . . . . . . . . . . . . . . . . . . 3
3. Role-based TE-MESH-GROUP TLV Formats . . . . . . . . . . . . 4
3.1. OSPF Role-based TE-MESH-GROUP TLV Format . . . . . . . . 4
3.2. IS-IS Role-based TE-MESH-GROUP Sub-TLV Format . . . . . . 6
4. Elements of Procedure . . . . . . . . . . . . . . . . . . . . 8
4.1. OSPF . . . . . . . . . . . . . . . . . . . . . . . . . . 9
4.2. IS-IS . . . . . . . . . . . . . . . . . . . . . . . . . . 10
5. Backward Compatibility . . . . . . . . . . . . . . . . . . . 11
6. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 11
6.1. OSPF . . . . . . . . . . . . . . . . . . . . . . . . . . 11
6.2. IS-IS . . . . . . . . . . . . . . . . . . . . . . . . . . 11
7. Security Considerations . . . . . . . . . . . . . . . . . . . 11
8. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 12
9. References . . . . . . . . . . . . . . . . . . . . . . . . . 12
9.1. Normative References . . . . . . . . . . . . . . . . . . 12
9.2. Informative References . . . . . . . . . . . . . . . . . 12
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 13
1. Introduction
A TE mesh-group [RFC4972] is defined as a group of LSRs that are
connected by a full mesh of TE LSPs. [RFC4972] specifies
Intermediate System-to-Intermediate System (IS-IS) and Open Shortest
Path First (OSPF) extensions to provide an automatic discovery of the
set of LSR members of a TE mesh-group in order to automate the
creation of such mesh of TE LSPs. This is called "auto-mesh TE" or
"auto-mesh". The auto-mesh TE largely simplifies the configurations
and deployments of TE LSPs.
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In some scenarios, it may not necessary to establish full mesh TE
LSPs among all the LSRs of a TE mesh-group. An example of the
scenarios is the mobile backhaul networks
([I-D.li-mpls-seamless-mpls-mbb]), TE LSPs are normally setup between
the Cell Site Gateways(CSGs) and the Radio Network Controller (RNC)
Site Gateways(RSGs). TE LSPs between/among CSGs and TE LSPs between
RSGs are not necessary. And normally, the amount of CSGs is very
large in the real deployments, with the auto-mesh mechanism
defined[RFC4972], full mesh TE LSPs will be established among the
CSGs and RSGs, this will result in large amount of unnecessary TE
LSPs established among CSGs and between RSGs. This may not be scale
for the CSG devices and is waste of network resources.
So, there are requirements to optimize the auto-mesh TE hence to
reduce the unnecessary TE LSPs. This document introduces a "role-
based auto-mesh TE" or "role-based auto-mesh" where the setup of the
TE LSPs are dependent on the roles of the LSRs within a TE mesh-
group. Therefore, besides the discovery of the membership of a TE
mesh-group, it needs to discover the role of each node in the TE
mesh-group.
Another scenario to which the role-based auto-mesh TE can apply is
the Resource Reservation Protocol-Traffic Engineering (RSVP-TE)
Point-to-Multipoint (P2MP) TE LSP[RFC4875] scenario. For a RSVP-TE
P2MP TE LSP, the root LSR has to know all the leaf LSRs before
signaling the P2MP TE LSP. The automatic discovery mechanisms
defined in this document can be used to discover the leaf LSRs for
P2MP TE LSPs.
This document defines IGP routing extensions to automatically
discover of the members and their roles of a TE mesh-group.
2. Role-based TE Mesh Group
A role-based TE mesh-group is a special TE mesh-group where TE LSPs
will not be established among all member LSRs. LSRs in a role-based
TE mesh-group will have different roles. The TE LSPs setup depends
on the roles of the LSRs in a TE mesh-group. This document
introduces two types of roles: Hub-Spoke LSRs, and Root-Leaf LSRs.
So there would be Hub-Spoke TE mesh-group and Root-Leaf TE mesh-
group.
For a Hub-Spoke TE mesh-group, an LSR can be either a Hub or Spoke
LSR in a group, but cannot be both. The rules for Hub-Spoke TE mesh-
group are as follows:
TE LSPs SHOULD only be setup between Spoke and Hub LSRs.
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TE LSPs MUST NOT be setup between/among Spoke LSRs.
TE LSPs MUST NOT be setup between/among Hub LSRs.
For a Root-Leaf TE mesh-group, an LSR can be a Root, a Leaf or both a
Root and Leaf LSR. Once the membership and roles are determined, the
root LSRs can signal the P2MP TE LSPs toward all the Leaf LSRs.
There may be multiple P2MP TE LSPs within a TE mesh-group.
How to signal the TE LSPs is out the scope of this document.
3. Role-based TE-MESH-GROUP TLV Formats
3.1. OSPF Role-based TE-MESH-GROUP TLV Format
The OSPF Role-based TE-MESH-GROUP TLV is used to advertise that an
LSR joins/leaves a TE mesh-group and the role of the LSR in the TE
mesh-group. The OSPF Role-based TE-MESH-GROUP TLV format for IPv4
(Figure 2) and IPv6 (Figure 3) 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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Type | Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| mesh-group-number 1 |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|H|S|R|L| Reserved |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Tail-end IPv4 address 1 |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Name length | Tail-end name 1 |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
~ ~
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| mesh-group-number n |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|H|S|R|L| Reserved |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Tail-end IPv4 address n |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Name length | Tail-end name n |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 2 - OSPF TE-MESH-GROUP TLV format (IPv4 Address)
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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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Type | Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| mesh-group-number 1 |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|H|S|R|L| Reserved |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| |
| Tail-end IPv6 address 1 |
| |
| |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Name length | Tail-end name 1 |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
~ ~
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| mesh-group-number n |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|H|S|R|L| Reserved |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| |
| Tail-end IPv6 address n |
| |
| |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Name length | Tail-end name n |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 3 - OSPF TE-MESH-GROUP TLV format (IPv6 Address)
The Type of OSPF TE-MESH-GROUP TLV for IPv4 is TBD1, the value of the
Length is variable.
The Type of OSPF TE-MESH-GROUP TLV for IPv6 is TBD2, the value of the
Length is variable.
The OSPF Role-based TE-MESH-GROUP TLV may contain one or more role-
based mesh-group entries. And each entry corresponds to a TE mesh-
group. The definition of the mesh-group-number, the Tail-end
address, the Name length and the Tail-end name in each role-based
mesh group entry is the same as that of OSPF TE-MESH-GROUP TLV
defined in [RFC4972].
In addition, for each mesh group entry, an four-octet flag field is
introduced and four flags are defined in this document. Other bits
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are reserved for future use and MUST be set to zero when sent, and
MUST be ignored when received.
The H (Hub) bit, when set, it indicates the LSR is a Hub LSR.
The S (Spoke) bit, when set, it indicates the LSR is a Spoke LSR.
The R (Root) bit, when set, it indicates an LSR is a Root LSR.
The L (Leaf) bit, when set, it indicates an LSR is a Leaf.
The R and Leaf bit can be both set, when both bits set, in indicates
an LSR is a Root and Leaf LSR. The R bit and Leaf bit are only used
for Root-Leaf TE mesh-group, for other TE mesh-groups, it MUST be set
to zero and MUST be ignored when received.
3.2. IS-IS Role-based TE-MESH-GROUP Sub-TLV Format
The IS-IS Role-based TE-MESH-GROUP sub-TLV is used to advertise that
an LSR joins/leaves a TE mesh-group and the role of the LSR in the TE
mesh-group. The IS-IS Role-based TE-MESH-GROUP sub-TLV format for
IPv4 (Figure 4) and IPv6 (Figure 5) is as follows:
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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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Type | Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| mesh-group-number 1 |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|H|S|R|L| Reserved |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Tail-end IPv4 address 1 |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Name length | Tail-end name 1 |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
~ ~
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| mesh-group-number n |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|H|S|R|L| Reserved |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Tail-end IPv4 address n |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Name length | Tail-end name n |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 4 - IS-IS TE-MESH-GROUP sub-TLV format (IPv4 Address)
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 |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| mesh-group-number 1 |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|H|S|R|L| Reserved |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| |
| Tail-end IPv6 address 1 |
| |
| |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Name length | Tail-end name 1 |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
~ ~
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| mesh-group-number n |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|H|S|R|L| Reserved |
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+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| |
| Tail-end IPv6 address n |
| |
| |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Name length | Tail-end name n |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 5 - IS-IS TE-MESH-GROUP sub-TLV format (IPv6 Address)
The Type of IS-IS TE-MESH-GROUP sub-TLV for IPv4 is TBD3, the value
of the Length is variable.
The Type of IS-IS TE-MESH-GROUP sub-TLV for IPv6 is TBD4, the value
of the Length is variable.
The IS-IS Role-based TE-MESH-GROUP sub-TLV may contain one or more
role-based mesh-group entries. And each entry corresponds to a TE
mesh-group. The definition of the fields, mesh-group-number, Tail-
end address, Name length and Tail-end name in each role-based mesh
group entry is the same as that of IS-IS TE-MESH-GROUP sub-TLV
defined in [RFC4972].
The H, S, R and L bits are defined as in Section 3.1 of this
document.
4. Elements of Procedure
The OSPF Role-based TE-MESH-GROUP TLV is carried within the OSPF
Routing Information LSA and the IS-IS Role-based TE-MESH-GROUP sub-
TLV is carried within the IS-IS Router capability TLV. As such,
elements of procedure are inherited from those defined in [RFC4970]
and [RFC4971] for OSPF and IS-IS respectively. Specifically, a
router MUST originate a new LSA/LSP whenever the content of this
information changes, or whenever required by regular routing
procedure (e.g., updates).
The Role-based TE-MESH-GROUP TLV is OPTIONAL and MUST NOT include
more than one of each of the IPv4 instances or the IPv6 instance. If
either the IPv4 or the IPv6 OSPF Role-based TE-MESH-GROUP TLV occurs
more than once within the OSPF Router Information LSA, only the first
instance is processed, subsequent TLV(s) SHOULD be silently ignored.
Similarly, if either the IPv4 or the IPv6 IS-IS Role-based TE-MESH-
GROUP sub-TLV occurs more than once within the IS-IS Router
capability TLV, only the first instance is processed, subsequent
TLV(s) SHOULD be silently ignored.
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4.1. OSPF
The Role-based TE-MESH-GROUP TLV is advertised within an OSPF Router
Information opaque LSA (opaque type of 4, opaque ID of 0) for OSPFv2
[RFC2328] and within a new LSA (Router Information LSA) for OSPFv3
[RFC5340]. The Router Information LSAs for OSPFv2 and OSPFv3 are
defined in [RFC4970].
A router MUST originate a new OSPF router information LSA whenever
the content of any of the advertised TLV changes or whenever required
by the regular OSPF procedure (LSA update (every LSRefreshTime)). If
an LSR desires to join or leave a particular TE mesh group or an LSR
desires to change its role in a mesh group, it MUST originate a new
OSPF Router Information LSA comprising the updated Role-based TE-
MESH-GROUP TLV. In the case of a join, a new entry will be added to
the role-based TE-MESH-GROUP TLV; if the LSR leaves a mesh-group, the
corresponding entry will be removed from the role-based TE-MESH-GROUP
TLV; if the LSR changes its role in the mesh group, the corresponding
entry will be updated in the role-based TE-MESH-GROUP TLV. Note that
these operations can be performed in the context of a single LSA
update. An implementation SHOULD be able to detect any change to a
previously received role-based TE-MESH-GROUP TLV from a specific LSR.
As defined in [RFC5250] for OSPVv2 and in [RFC5340] for OSPFv3, the
flooding scope of the Router Information LSA is determined by the LSA
Opaque type for OSPFv2 and the values of the S1/S2 bits for OSPFv3.
For OSPFv2 Router Information opaque LSA:
- Link-local scope: type 9;
- Area-local scope: type 10;
- Routing-domain scope: type 11. In this case, the flooding scope is
equivalent to the Type 5 LSA flooding scope.
For OSPFv3 Router Information LSA:
- Link-local scope: OSPFv3 Router Information LSA with the S1 and S2
bits cleared;
- Area-local scope: OSPFv3 Router Information LSA with the S1 bit set
and the S2 bit cleared;
- Routing-domain scope: OSPFv3 Router Information LSA with S1 bit
cleared and the S2 bit set.
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A router may generate multiple OSPF Router Information LSAs with
different flooding scopes.
The Role-based TE-MESH-GROUP TLV may be advertised within an Area-
local or Routing-domain scope Router Information LSA, depending on
the MPLS TE mesh group profile:
- If the MPLS TE mesh-group is contained within a single area (all
the LSRs of the mesh-group are contained within a single area), the
Role-based TE-MESH-GROUP TLV MUST be generated within an Area-local
Router Information LSA.
- If the MPLS TE mesh-group spans multiple OSPF areas, the TE Role-
based mesh- group TLV MUST be generated within a Routing-domain scope
router information LSA.
When the router receives Role-based TE-MESH-GROUP TLV, it SHOULD
setup MPLS TE LSPs according rules which defined in the Section 3.
4.2. IS-IS
The Role-based TE-MESH-GROUP sub-TLV is advertised within the IS-IS
Router CAPABILITY TLV defined in [RFC4971].
An IS-IS router MUST originate a new IS-IS LSP whenever the content
of any of the advertised sub-TLV changes or whenever required by
regular IS-IS procedure (LSP updates). If an LSR desires to join or
leave a particular TE mesh group or an LSR desires to change its role
in a mesh group, it MUST originate a new LSP comprising the refreshed
IS-IS Router capability TLV comprising the updated TE-MESH-GROUP sub-
TLV. In the case of a join, a new entry will be added to the TE-
MESH-GROUP sub-TLV; if the LSR leaves a mesh-group, the corresponding
entry will be deleted from the TE-MESH-GROUP sub-TLV; if the LSR
changes its role in the mesh group, the corresponding entry will be
updated in the role-based TE-MESH-GROUP sub-TLV. Note that these
operations can be performed in the context of a single update. An
implementation SHOULD be able to detect any change to a previously
received TE-MESH-GROUP sub-TLV from a specific LSR.
If the flooding scope of a Role-based TE-MESH-GROUP sub-TLV is
limited to an IS-IS level/area, the sub-TLV MUST NOT be leaked across
level/area and the S flag of the Router CAPABILITY TLV MUST be
cleared. Conversely, if the flooding scope of a Role-based TE-MESH-
GROUP sub-TLV is the entire routing domain, the TLV MUST be leaked
across IS-IS levels/areas, and the S flag of the Router CAPABILITY
TLV MUST be set. In both cases, the flooding rules specified in
[RFC4971] apply.
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As specified in [RFC4971], a router may generate multiple IS-IS
Router CAPABILITY TLVs within an IS-IS LSP with different flooding
scopes.
When the router receives Role-based TE-MESH-GROUP sub-TLV, it SHOULD
setup MPLS TE LSPs according rules which defined in the Section 3.
5. Backward Compatibility
For a role-based TE mesh-group, if there are some LSRs only
supporting mechanisms defined [RFC4972], all the LSRs of the mesh-
group MUST process as defined in [RFC4972]. The operators should
avoid to add an LSR that does not support role-based auto-mesh TE to
a role-based TE mesh-group.
6. IANA Considerations
6.1. OSPF
The registry for the Router Information LSA is defined in [RFC4970].
IANA assigned a new OSPF TLV code-point for the Role-based TE-MESH-
GROUP TLVs carried within the Router Information LSA.
Value TLV References
----- -------- ----------
TBD1 Role-based TE-MESH-GROUP TLV (IPv4) this document
TBD2 Role-based TE-MESH-GROUP TLV (IPv6) this document
6.2. IS-IS
The registry for the Router Capability TLV is defined in [RFC4971].
IANA assigned a new IS-IS sub-TLV code-point for the TE-MESH-GROUP
sub-TLVs carried within the IS-IS Router Capability TLV.
Value Sub-TLV References
----- -------- ----------
TBD3 Role-based TE-MESH-GROUP sub-TLV (IPv4) this document
TBD4 Role-based TE-MESH-GROUP sub-TLV (IPv6) this document
7. Security Considerations
The function described in this document does not create any new
security issues for the OSPF and IS-IS protocols, the security
considerations described in [RFC4972] apply here.
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8. Acknowledgements
The authors would like to thank Loa Andersson for his valuable
comments.
The authors would also like to thank the authors of [RFC4972] from
where we have taken most of the elements procedures.
9. References
9.1. Normative References
[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
Requirement Levels", BCP 14, RFC 2119, March 1997.
[RFC2328] Moy, J., "OSPF Version 2", STD 54, RFC 2328, April 1998.
[RFC4970] Lindem, A., Shen, N., Vasseur, JP., Aggarwal, R., and S.
Shaffer, "Extensions to OSPF for Advertising Optional
Router Capabilities", RFC 4970, July 2007.
[RFC4971] Vasseur, JP., Shen, N., and R. Aggarwal, "Intermediate
System to Intermediate System (IS-IS) Extensions for
Advertising Router Information", RFC 4971, July 2007.
[RFC4972] Vasseur, JP., Leroux, JL., Yasukawa, S., Previdi, S.,
Psenak, P., and P. Mabbey, "Routing Extensions for
Discovery of Multiprotocol (MPLS) Label Switch Router
(LSR) Traffic Engineering (TE) Mesh Membership", RFC 4972,
July 2007.
[RFC5250] Berger, L., Bryskin, I., Zinin, A., and R. Coltun, "The
OSPF Opaque LSA Option", RFC 5250, July 2008.
[RFC5340] Coltun, R., Ferguson, D., Moy, J., and A. Lindem, "OSPF
for IPv6", RFC 5340, July 2008.
9.2. Informative References
[I-D.li-mpls-seamless-mpls-mbb]
Li, Z., Li, L., Morillo, M., and T. Yang, "Seamless MPLS
for Mobile Backhaul", draft-li-mpls-seamless-mpls-mbb-00
(work in progress), July 2013.
[RFC4875] Aggarwal, R., Papadimitriou, D., and S. Yasukawa,
"Extensions to Resource Reservation Protocol - Traffic
Engineering (RSVP-TE) for Point-to-Multipoint TE Label
Switched Paths (LSPs)", RFC 4875, May 2007.
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Authors' Addresses
Zhenbin Li
Huawei
Email: lizhenbin@huawei.com
Mach(Guoyi) Chen
Huawei
Email: mach.chen@huawei.com
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