CCAMP Working Group Zafar Ali, Ed.
Internet Draft George Swallow, Ed.
Intended status: Standard Track Cisco Systems
Expires: January 3, 2015 F. Zhang, Ed.
Huawei
D. Beller, Ed.
Alcatel-Lucent
July 4, 2014
Resource ReserVation Protocol-Traffic Engineering (RSVP-TE) Path
Diversity using Exclude Route
draft-ietf-ccamp-lsp-diversity-04.txt
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Abstract
RFC 4874 specifies methods by which path exclusions may be
communicated during RSVP-TE signaling in networks where precise
explicit paths are not computed by the LSP source node. This
document specifies procedures for additional route exclusion
subobject based on Paths currently existing or expected to exist
within the network.
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 RFC 2119 [RFC2119].
Table of Contents
1. Introduction
............................................... 2
1.1. Client Initiated Identifier ........................ 5
1.2. PCE allocated Identifiers
.......................... 6
1.3. UNI-N allocated Identifiers
........................ 7
2. RSVP-TE signaling extensions
............................... 9
2.1. Diversity XRO Subobject ............................ 9
2.1.1. Tunnel identifier TLVs ........................... 12
2.1.2. Path Key TLVs .................................... 14
2.1.3. Path Affinity Set TLVs ........................... 16
2.2. Processing rules for the Diversity XRO subobject ... 19
2.2.1. Processing rules for the tunnel identifier TLVs .. 20
2.2.2. Processing rules for the Path Key TLVs ........... 22
2.2.3. Processing rules for the PAS TLVs
................ 23
2.3. Diversity EXRS Subobject ........................... 25
3. Security Considerations .................................... 27
4. IANA Considerations
........................................ 27
6. References ................................................. 28
6.1. Normative References ............................... 28
6.2. Informative References ............................. 29
1. Introduction
Path diversity for multiple connections is a well-known Service
Provider requirement. Diversity constraints ensure that Label-
Switched Paths (LSPs) may be established without sharing
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resources, thus greatly reducing the probability of simultaneous
connection failures.
When a source node has full topological knowledge and is permitted
to signal an Explicit Route Object (ERO), diverse paths can be
computed locally. However, there are scenarios when path
computations are performed by remote nodes, thus there is a need for
relevant diversity constraints to be communicated to those nodes.
These include (but are not limited to):
. LSPs with loose hops in the ERO, e.g. inter-domain LSPs;
. Generalized Multi-Protocol Label Switching (GMPLS) User-
Network Interface (UNI) where path computation may be performed
by the core node [RFC4208].
[RFC4874] introduced a means of specifying nodes and resources to
be excluded from a route, using the eXclude Route Object (XRO) and
Explicit Exclusion Route Subobject (EXRS). It facilitates the
calculation of diverse paths for LSPs based on known properties of
those paths including addresses of links and nodes traversed, and
Shared Risk Link Groups (SRLGs) of traversed links. Employing
these mechanisms requires that the source node that initiates
signaling knows the relevant properties of the path(s) from which
diversity is desired. However, there are circumstances under which
this may not be possible or desirable, including (but not limited
to):
. Exclusion of a path which does not originate, terminate or
traverse the source node signaling the diverse LSP, in which
case the addresses and SRLGs of the path from which diversity
is required are unknown to the source node.
. Exclusion of a path which is known to the source node of the
diverse LSP, however the node has incomplete or no path
information, e.g. due to policy. In other words, the scenario
in which the reference path is known by the source / requesting
node but the properties required to construct an XRO object are
not fully known. Inter-domain and GMPLS overlay networks can
present such restrictions.
This is exemplified in the Figure 1, where overlay reference
model from [RFC4208] is shown.
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Overlay Overlay
Network +----------------------------------+ Network
+---------+ | | +---------+
| +----+ | | +-----+ +-----+ +-----+ | | +----+ |
| | | | UNI | | | | | | | | UNI | | | |
| -+ EN1+-+-----+--+ CN1 +----+ CN2 +----+ CN3 +---+-----+-+ EN3+- |
| | | | +--+--+ | | | | | | +---+-| | |
| +----+ | | | +--+--+ +--+--+ +--+--+ | | | +----+ |
+---------+ | | | | | | | +---------+
| | | | | | |
+---------+ | | +--+--+ | +--+--+ | | +---------+
| +----+ | | | | | +-------+ +-----+ | +----+ |
| | +-+--+ | | CN4 +---------------+ CN5 | | | | | |
| -+ EN2+-+-----+--+ | | +---+-----+-+ EN4+- |
| | | | UNI | +-----+ +-----+ | UNI | | | |
| +----+ | | | | +----+ |
+---------+ +----------------------------------+ +---------+
Overlay Core Network Overlay
Network Network
Legend: EN - Edge Node
CN - Core Node
Figure 1: Overlay Reference Model [RFC4208]
Figure 1 depicts two types of UNI connectivity: single-homed and
dual-homed ENs (which also applies to higher order multi-homed
connectivity.). Single-homed Edge Node (EN) devices are connected
to a single Core Node (CN) device via a single UNI link. This
single UNI link may constitute a single point of failure. UNI
connection between EN1 and CN1 is an example of singled-homed UNI
connectivity.
A single point of failure caused by a single-homed UNI can be
avoided when the EN device is connected to two different CN
devices, as depicted for EN2 in Figure 1. For the dual-homing
case, it is possible to establish two different UNI connections
from the same source EN device to the same destination EN device.
For example, two connections from EN2 to EN3 may use the two UNI
links EN2-CN1 and EN2-CN4. To avoid single points of failure
within the provider network, it is necessary to also ensure path
(LSP) diversity within the core network.
In Figure 1, the CNs typically performs path computation.
Information sharing across the UNI boundary is restricted based
on the policy rules imposed by the core network. Typically, the
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core network topology information is not exposed to the ENs. In
such networks, consider a use case where an LSP from EN2 to EN4
needs to be SRLG diverse from an LSP from EN1 to EN3. In this
case, EN2 may not know SRLG attributes of the EN1- EN3 LSP and
hence cannot construct an XRO to exclude these SRLGs. In this
example EN2 cannot use procedures described in [RFC4874].
Similarly, in the context of dual-homed UNI example described
above, an LSP from EN2 to EN3 going via CN1 needs to be diverse
from an LSP from EN2 to EN3 going via CN4. Again in this case,
[RFC4874] based exclusions cannot be used.
This document addresses these diversity requirements by
introducing the notion of excluding the path taken by particular
LSP(s). The reference LSP(s) with which diversity is required is
identified by an "identifier". The type of identifier to use is
highly dependent on the networking deployment scenario. For
example, if the identifier is client initiated, the network
allocates identifier or a Path Computation Element (PCE) manages
identifier. Consequently, this document defines three different
types of identifiers: client initiated identifier, PCE allocated
Identifier and network allocated Identifier, as detailed in the
following sections.
1.1. Client Initiated Identifier
There are scenarios in which the ENs have the following
requirements for the diversity identifier:
- The identifier is controller by the client side and is
specified as part of the service request.
- Both client and server should understand the identifier.
- The identifier needs to be reference able even if the LSP
referenced by it is not yet signaled.
- The identifier should be stable for a long period of time.
- The identifier should be stable even when the tunnel is
rerouted.
- The identifier should be human readable.
The above-mentioned requirements are met by using RSVP tunnel/
LSP Forwarding Equivalence Class (FEC) as the identifier.
Consequently, RSVP tunnel/ LSP FEC is used as client initiated
identifier.
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The usage of the client-initiated identifier is illustrated by
using Figure 1. Suppose a tunnel from EN2 to EN4 needs to be
diverse with respect to a tunnel from EN1 to EN3. Lets assume
tunnel FEC of the EN1-EN3 tunnel is FEC1, where FEC1 is defined
by the tuple (tunnel-id = T1, source address = EN1.ROUTE
Identifier (RID), destination address = EN3.RID, extended tunnel-
id = EN1.RID). Similarly, tunnel FEC of the EN2-EN3 tunnel is
FEC2, where FEC2 is defined by the tuple (tunnel-id = T2, source
address = EN2.RID, destination address = EN4.RID, extended
tunnel-id = EN2.RID). EN1-EN3 tunnel is signaled such that it
specifies the exclusion requirement from FEC2. Similarly, EN2-EN3
tunnel is signaled such that it specifies the exclusion
requirement from FEC1. In order to maintain diversity between
these two connections within the core network, it is assumed that
the core network implements Crank back Signaling [RFC4920].
Similarly, diversity within the core network for a dual homed UNI
case is satisfied by the use of Crank back Signaling [RFC4920].
1.2. PCE allocated Identifiers
In scenarios where a PCE is deployed and used to perform path
computation, the core edge node (e.g., node CN1 in Figure 1)
could consult a PCE to allocate identifiers, which are used to
signal path diversity constraints. In other scenarios a PCE is
deployed in each border node or a PCE is part of the Network
Management System (NMS). In all these cases, the Path key as
defined in [RFC5520] can be used in RSVP signaling as the
identifier to ensure diversity.
The usage of specifying LSP diversity using Path Key is
exemplified in Figure 2, where a simple network with two domains
is shown. It is desired to set up a pair of path-disjoint LSPs
from the source in Domain 1 to the destination in Domain 2, but
the domains keep strict confidentiality about all path and
topology information.
The first LSP is signaled by the source with ERO {A, B, loose Dst}
and is set up with the path {Src, A, B, U, V, W, Dst}. However,
when sending the RRO out of Domain 2, node U would normally strip
the path and replace it with a loose hop to the destination. With
this limited information, the source is unable to include enough
detail in the ERO of the second LSP to avoid it taking, for
example, the path {Src, C, D, X, V, W, Dst} for path-disjointness.
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--------------------- -----------------------------
| Domain 1 | | Domain 2 |
| | | |
| --- --- | | --- --- --- |
| | A |--| B |--+--+--| U |--| V |---| W | |
| / --- --- | | --- --- --- \ |
| ---/ | | / / \--- |
| |Src| | | / / |Dst| |
| ---\ | | / / /--- |
| \ --- --- | | --- / --- / --- / |
| | C |--| D |--+--+--| X |---| Y |--| Z | |
| --- --- | | --- --- --- |
| | | |
--------------------- -----------------------------
Figure 2: A Simple Multi-Domain Network
In order to improve the situation, node U performs the PCE
function and replaces the path segment {U, V, W} in the RRO with
a Path Key Subobject [RFC5553]. The Path Key Subobject assigns an
"identifier" to the key. The PCE ID in the message indicates that
it was node U that made the replacement.
With this additional information, the source is able to signal
the subsequent LSPs with the ERO set to {C, D, exclude Path
Key(EXRS), loose Dst}. When the signaling message reaches node X,
it can consult node U to expand the Path Key and know how to
avoid the path of the first LSP. Alternatively, the source could
use an ERO of {C, D, loose Dst} and include an XRO containing the
Path Key.
1.3. Network allocated Identifiers
There are scenarios in which the network provides diversity
information for a service that allows the client device to
include this information in the signaling message. In this
section two signaling approaches are outlined that use network
allocated identifiers. While both methods could be implemented in
the same core network, it is very likely that a core network
supports only one of the two mechanisms.
The first method assumes that core network Shared Resource Link
Group (SRLG) identifier information is both available and
shareable (by policy) with the ENs. In this case, the procedure
defined in [DRAFT-SRLG-RECORDING] can be used to collect SRLG
identifiers associated with an LSP (say LSP1). Suppose that LSP2
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needs to be diverse with respect to LSP1. When the EN constructs
the RSVP signaling message for setting up LSP2, it can insert the
SRLG identifiers associated with LSP1 as diversity constraints
into the XRO using the procedure described in [RFC4874]. This
method is not discussed further as it utilizes existing RSVP
protocol mechanisms for collecting SRLG information and passing
this diversity information to the CN.
The second method assumes that core network SRLG identifiers are
either not available or not shareable with the ENs based on
policies enforced by core network. In this case, a signaling
mechanism is defined where information signaled to the CN via the
UNI does not require shared knowledge of provider SRLG
information. For this purpose, notion of Path Affinity Set (PAS)
is used for abstracting SRLG information. The motive behind the
PAS information is to have as little exchange of diversity
information as possible between the core network (CNs) and the
client devices (ENs). I.e., rather than a detailed SRLG list, the
PAS contains an abstract SRLG identifier associated with a given
path.
There are two types of diversity information in the PAS. The
first type of information is a single PAS identifier. The Second
part is the optional PATH information, in the form of Source and
Destination addresses of a path. This mechanism can also be
applied to L1 VPNs and in this particular case, the identifier
only needs to be unique within the scope of a particular VPN.
A CN on the core network boundary interprets the specific PAS
identifier, for example, "123" as meaning to exclude the core
network SRLG information (or equivalent) that has been allocated
by LSPs associated with this PAS identifier value. For example,
if a Path exists for the LSP with the identifier "123", the CN
would use local knowledge of the core network SRLGs associated
with the "123" LSPs and use those SRLGs as constraints for path
computation. In other words, two LSPs that need to be diverse
both signal "123" and the CNs interpret this as meaning not to
use shared resources. Alternatively, a CN could use the PAS
identifier to select from already established LSPs. Once the path
is established core network allocated the "123" identifier or
optionally another PAS identifier for that VPN that replaces
"123".
The optional PAS source and destination address tuple represents
one or more source addresses and destination addresses associated
with the EN PAS identifier. These associated address tuples
represent paths that use resources that should be excluded for
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the establishment of the current LSP. The address tuple
information gives both finer grain details on the path diversity
request and serves as an alternative identifier in the case when
the PAS identifier is not known by the CN. The address tuples
used in signaling is within a client network context and its
interpretation is local to a CN that receives a Path request from
an EN. The CN can use the address information to relate to CN
addresses and core network SRLG information. When a CN satisfies
a connection setup for a (SRLG) diverse signaled path, the CN may
optionally record the core network SRLG information for that
connection in terms of CN based parameters and associates that
with the EN addresses in the Path message. Specifically for
L1VPNs, Port Information tables (PIT) [RFC5251] can be leveraged
to translate between client (EN) based addresses and core network
based addresses. The PAS and associated core network addresses
with core network SRLG information can be distributed via the IGP
in the core network (or by other means such as configuration);
they can be utilized by other CNs when other ENs are requesting
paths to be setup that would require path/connection diversity.
In the VPN case, this information is distributed on a VPN basis
and contains a PAS identifier, CN addresses and SRLG information.
If diversity is not signaled, the assumption is that no diversity
is required and the core network is free to route the LSP to
optimize traffic. No Path affinity set information needs to be
recorded for these LSPs. If a diversity object is included in
the connection request, the CN in the core network should be able
to determine (look-up) the existing core network SRLG information
and choose an LSP that is maximally diverse from other LSPs.
The Path Affinity Set identifier is independent of the mechanism
the EN or the CN use for diversity. The Path Affinity Set is a
single identifier that can be used to request diversity and
associate diversity.
2. RSVP-TE signaling extensions
This section describes the signaling extensions required to
address the aforementioned requirements and use cases.
2.1. Diversity XRO Subobject
New Diversity XRO subobjects are defined by this document 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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|L| Type |Attribute Flags|Exclusion Flags| Reserved |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| TLVs ... |
// //
| |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
L:
The L-flag is used as for the XRO subobjects defined in
[RFC4874], i.e.,
0 indicates that the attribute specified MUST be excluded.
1 indicates that the attribute specified SHOULD be avoided.
Type
Type for diversity XRO subobject (to be assigned by IANA;
suggested value: 37).
Attribute Flags:
The Attribute Flags are used to communicate desirable
attributes of the LSP being signaled. The following flags
are defined. Each flag acts independently. Any combination
of flags is permitted.
0x01 = Destination node exception
Indicates that exclusion does not apply to the
destination node of the LSP being signaled.
0x02 = Processing node exception
Indicates that exclusion does not apply to the border
node(s) performing ERO expansion for the LSP being
signaled. Ingress UNI-N node is an example of such
nodes.
0x04 = Penultimate node exception
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Indicates that the penultimate node of the LSP being
signaled MAY be shared with the excluded path even when
this violates the exclusion flags.
0x08 = LSP ID to be ignored
This flag is only applicable to the IPv4/ IPv6 Point-to-
Point tunnel identifier TLVs of the Diversity XRO
subobjects defined in section 2.1.1. In this context,
the flag indicates tunnel level exclusion. Specifically,
this flag is used to indicate that the lsp-id field of
the IPv4/ IPv6 Point-to-Point tunnel identifier TLVs is
to be ignored and the exclusion applies to any LSP
matching the rest of the supplied FEC.
Exclusion Flags
The Exclusion-Flags are used to communicate the desired
type(s) of exclusion. The following flags are defined.
0x01 = SRLG exclusion
Indicates that the path of the LSP being signaled is
requested to be SRLG diverse from the excluded path
specified by the Diversity subobject.
0x02 = Node exclusion
Indicates that the path of the LSP being signaled is
requested to be node diverse from the excluded path
specified by the Diversity subobject.
(Note: the meaning of this flag may be modified by
the value of the Attribute-flags.)
0x04 = Link exclusion
Indicates that the path of the LSP being signaled is
requested to be link diverse from the path specified
by the Diversity subobject.
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TLVs (Type-Length-Value tuples) have the following format. Only
one TLV is allowed in the Diversity XRO subobject. However,
multiple Diversity XRO subobjects may be present in an XRO.
0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Type | Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Value |
// //
| |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Types (2 bytes): This document defines the following types of
TLVs:
- Type = 1: IPv4 Point-to-Point tunnel identifier.
- Type = 2: IPv6 Point-to-Point tunnel identifier.
- Type = 3: IPv4 Path Key.
- Type = 4: IPv6 Path Key.
- Type = 5: IPv4 Path Affinity Set (PAS).
- Type = 6: IPv6 Path Affinity Set (PAS).
Format of the individual TLVs is described in the following.
2.1.1. Tunnel identifier TLVs
The IPv4 and IPv6 Point-to-Point (P2P) tunnel identifier TLVs for
diversity XRO subobjects are defined as follows.
2.1.1.1. IPv4 Point-to-Point tunnel identifier TLV
0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Type = 1 | Length = 24 |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| IPv4 tunnel end point address |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
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| Must Be Zero | Tunnel ID |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Extended Tunnel ID |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| IPv4 tunnel sender address |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Must Be Zero | LSP ID |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Type:
IPv4 Point-to-Point tunnel identifier TLV (to be assigned
by IANA; suggested value: 1).
Length:
The length contains the total length of the TLV in bytes,
including the type and length fields. The length is always
24.
The remaining fields are as defined in [RFC3209].
Please note that the L-bit, exclusion and attribute flags
defined at the diversity XRO subobject level in Section 2.1
are equally applicable to the IPv4 Point-to-Point tunnel
identifier TLV.
2.1.1.2. IPv6 Point-to-Point tunnel identifier TLV
0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Type = 2 | Length = 60 |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| IPv6 tunnel end point address |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| IPv6 tunnel end point address (cont.) |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| IPv6 tunnel end point address (cont.) |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| IPv6 tunnel end point address (cont.) |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Must Be Zero | Tunnel ID |
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+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Extended Tunnel ID |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Extended Tunnel ID (cont.) |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Extended Tunnel ID (cont.) |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Extended Tunnel ID (cont.) |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| IPv6 tunnel sender address |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| IPv6 tunnel sender address (cont.) |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| IPv6 tunnel sender address (cont.) |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| IPv6 tunnel sender address (cont.) |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Must Be Zero | LSP ID |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Type:
IPv6 Point-to-Point tunnel identifier TLV (to be assigned
by IANA; suggested value: 2).
Length:
The length contains the total length of the TLV in bytes,
including the type and length fields. The length is always
60.
The remaining fields are as defined in [RFC3209].
Please note that the L-bit, exclusion and attribute flags
defined at the diversity XRO subobject level in Section 2.1
are equally applicable to the IPv6 Point-to-Point tunnel
identifier TLV.
2.1.2. Path Key TLVs
The IPv4 and IPv6 Path Key TLVs for diversity XRO subobjects are
defined as follows.
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2.1.2.1. IPv4 Path Key TLV
0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Type = 3 | Length = 12 |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Must Be Zero | Path Key |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| PCE ID (4 bytes) |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Type:
IPv4 Path Key TLV (to be assigned by IANA; suggested
value: 3).
Length:
The length contains the total length of the TLV in bytes,
including the type and length fields. The length is always
12.
Path Key:
Path Key is defined in [RFC5553].
PCE-ID:
The IPv4 address of a node that assigned the Path Key
identifier and that can return an expansion of the Path Key
or use the Path Key as exclusion in a path computation.
Please note that exclusion and attribute flags defined at the
diversity XRO subobject level in Section 2.1 are equally
applicable to the IPv4 Path Key TLV.
2.1.2.2. IPv6 Path Key TLV
0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Type = 4 | Length = 24 |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
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| Must Be Zero | Path Key |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| PCE ID (16 bytes) |
| |
| |
| |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Type:
IPv4 Path Key TLV (to be assigned by IANA; suggested
value: 4).
Length:
The length contains the total length of the TLV in bytes,
including the type and length fields. The length is always
24.
Path Key:
Path Key is defined in [RFC5553].
PCE-ID:
The IPv6 address of a node that assigned the Path Key
identifier and that can return an expansion of the Path Key
or use the Path Key as exclusion in a path computation.
Please note that the L-bit, exclusion and attribute flags
defined at the diversity XRO subobject level in Section 2.1
are equally applicable to the IPv6 Path Key TLV.
2.1.3. Path Affinity Set TLVs
The IPv4 and IPv6 Path Affinity Set (PAS) TLVs for diversity XRO
subobjects are defined as follows.
2.1.3.1. IPv4 PAS TLV
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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
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| Type = 5 | Length = 16 |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Path Affinity Set identifier |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| IPv4 Path Source Address |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| IPv4 Path Destination Address |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Type:
IPv4 PAS TLV (to be assigned by IANA; suggested value: 5).
Length:
The length contains the total length of the TLV in bytes,
including the type and length fields. The length is always
16.
Path Affinity Set identifier:
The Path affinity Set identifier (4 bytes) is a single
number that represents a summarized SRLG for this path.
IPv4 Path Source Address:
The IPv4 address of the source node associated with the
Path.
IPv4 Path Destination Address:
The IPv4 address of the destination node associated with
the Path.
Please note that L-bit, exclusion and attribute flags defined
at the diversity XRO subobject level in Section 2.1 are
equally applicable to the IPv4 PAS TLV.
2.1.3.2. IPv6 PAS TLV
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
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+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Type = 6 | Length = 40 |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Path Affinity Set identifier |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| IPv6 Path Source Address |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| IPv6 Path Source Address (cont.) |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| IPv6 Path Source Address (cont.) |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| IPv6 Path Source Address (cont.) |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| IPv6 Path Destination Address |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| IPv6 Path Destination Address (cont.) |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| IPv6 Path Destination Address (cont.) |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| IPv6 Path Destination Address (cont.) |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Type:
IPv6 PAS TLV (to be assigned by IANA; suggested value: 6).
Length:
The length contains the total length of the TLV in bytes,
including the type and length fields. The length is always
40.
Path Affinity Set identifier:
The Path affinity Set identifier (4 bytes) is a single
number that represents a summarized SRLG for this path.
IPv6 Path Source Address:
The IPv6 address of the source node associated with the
Path.
IPv6 Path Destination Address:
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The IPv6 address of the destination node associated with
the Path.
Please note that the L-bit, exclusion and attribute flags
defined at the diversity XRO subobject level in Section 2.1
are equally applicable to the IPv6 PAS TLV.
2.2. Processing rules for the Diversity XRO subobject
The procedure defined in [RFC4874] for processing XRO and EXRS is
not changed by this document.
If the processing node cannot recognize the Diversity XRO
subobject or the TLV contained in it, the node follows procedure
defined in [RFC4874].
An XRO object MAY contain multiple Diversity subobjects. However,
all Diversity subobjects are expected to contain the same TLV
type. If a Path message contains an XRO with Diversity subobjects
with TLVs of different types, the processing node SHOULD return a
PathErr with the error code "Routing Problem" (24) and error sub-
code "XRO Too Complex" (68). If the processing node is the
destination for the LSP being signaled, it SHOULD NOT process a
Diversity XRO subobject.
The attribute-flags affect the processing of the Diversity XRO
subobject as follows:
o When the "destination node exception" flag is not set, the
exclusion flags SHOULD also be respected for the
destination node.
o When the "processing node exception" flag is not set, the
exclusion flags SHOULD also be respected for the
processing node.
o When the "penultimate node exception" flag is not set, the
exclusion flags SHOULD also be respected for the
penultimate node.
o The use of "LSP ID to be ignored" flag is only defined for
the IPv4 and IPv6 tunnel identifier TLVs. This flag is
never set and is always ignored in processing all other
TLVs. When the "LSP ID to be ignored" flag is set, the
processing node MUST calculate a path based on exclusions
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from the paths of all known LSPs matching the tunnel-id,
source, destination and extended tunnel-id specified in
the subobject (i.e., tunnel level exclusion). When this
flag is not set, the lsp-id is not ignored and the
exclusion applies only to the specified LSP (i.e., LSP
level exclusion).
The rest of the processing role depends on the TLV carried by the
object.
2.2.1. Processing rules for the tunnel identifier TLVs
This section describes processing rules for the IPv4 and IPv6
tunnel identifier TLVs.
If the L-flag of the diversity XRO subobject is not set, the
processing node follows the following procedure:
- The processing node MUST ensure that any path calculated for
the signaled LSP respects the requested exclusion flags with
respect to the excluded path referenced by the subobject,
including local resources.
- If the processing node fails to find a path that meets the
requested constraint, the processing node MUST return a PathErr
with the error code "Routing Problem" (24) and error sub-code
"Route blocked by Exclude Route" (67).
- If the excluded path referenced in the tunnel identifier TLV
is unknown to the processing node, the processing node SHOULD
ignore the tunnel identifier TLV in the diversity XRO subobject
of XRO and SHOULD proceed with the signaling request. After
sending the Resv for the signaled LSP, the processing node
SHOULD return a PathErr with the error code "Notify Error" (25)
and error sub-code "Route of XRO tunnel identifier unknown"
(value to be assigned by IANA, suggested value: 13) for the
signaled LSP.
If the L-flag of the diversity XRO subobject is set, the
processing node follows the procedure below:
- The processing node SHOULD respect the requested exclusion
flags with respect to the excluded path to the extent possible.
- If the processing node fails to find a path that meets the
requested constraint, it SHOULD proceed with signaling using a
suitable path that meets the constraint as far as possible.
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After sending the Resv for the signaled LSP, it SHOULD return a
PathErr message with error code "Notify Error" (25) and error
sub-code "Failed to respect Exclude Route" (value: to be
assigned by IANA, suggest value: 14) to the source node.
- If the excluded path referenced in the tunnel identifier TLV
is unknown to the processing node, the processing node SHOULD
ignore the tunnel identifier TLV in the diversity XRO subobject
of XRO and SHOULD proceed with the signaling request. After
sending the Resv for signaled LSP, the processing node SHOULD
return a PathErr message with the error code "Notify Error"
(25) and error sub-code "Route of XRO tunnel identifier
unknown" for the signaled LSP.
If, subsequent to the initial signaling of a diverse LSP:
- An excluded path referenced in the diverse LSP's XRO tunnel
identifier becomes known to the processing node (e.g. when the
excluded path is signaled), or
- A change in the excluded path becomes known to the processing
node, the processing node SHOULD re-evaluate the exclusion and
diversity constraints requested by the diverse LSP to determine
whether they are still satisfied.
- If the requested exclusion constraints for the diverse LSP
are no longer satisfied and an alternative path for the diverse
LSP that can satisfy those constraints exists, the processing
node SHOULD send a PathErr message for the diverse LSP with the
error code "Notify Error" (25) and a new error sub-code
"compliant path exists" (value: to be assigned by IANA, suggest
value: 15). A source node receiving a PathErr message with this
error code and sub-code combination MAY try to reoptimize the
diverse tunnel to the new compliant path.
- If the requested exclusion constraints for the diverse LSP
are no longer satisfied and no alternative path for the diverse
LSP that can satisfy those constraints exists, then:
o If the L-flag was not set in the original exclusion, the
processing node MUST send a PathErr message for the
diverse LSP with the error code "Routing Problem" (24) and
error sub-code "Route blocked by Exclude Route" (67). The
PSR flag SHOULD NOT be set.
o If the L-flag was set in the original exclusion, the
processing node SHOULD send a PathErr message for the
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diverse LSP with the error code error code "Notify Error"
(25) and error sub-code "Failed to respect Exclude Route"
(value: to be assigned by IANA, suggest value: 14).
The following rules apply whether or not the L-flag is set:
- A source node receiving a PathErr message with the error code
"Notify Error" (25) and error sub-codes "Route of XRO tunnel
identifier unknown" or "Failed to respect Exclude Route" MAY
take no action.
2.2.2. Processing rules for the Path Key TLVs
This section describes processing rules for the IPv4 and IPv6
Path Key TLVs.
An EN may include a path-key identifier (PKS) in the path-key
TLVs of the diversity XRO subobject to convey diversity
constraints. In order to exclude multiple PKS, an EN may include
multiple diversity XRO subobjects each with a different path-key.
If the node, receiving the path-key TLV, cannot recognize the
subobject, it will react according to [RFC4874] and SHOULD ignore
the constraint. Otherwise, if it decodes the path-key TLV but
cannot find a route/route segment meeting the constraint:
-if L flag is set to 0, it will react according to [RFC4874]
and SHOULD send a PathErr message with the error code
"Routing Problem" (24) and the error sub-code "Route blocked
by Exclude Route" (67).
-if L flag is set to 1, which means the node SHOULD try to
be as much diversified as possible with the specified
resource. If it cannot fully support the constraint, it
SHOULD send a PathErr message with the error code/value
combination "Notify Error" / "Failed to respect Exclude
Route" (value: to be assigned by IANA, suggest value: 14).
The following rules apply whether or not the L-flag is set:
- A source node receiving a PathErr message with the error code
"Notify Error" (25) and error sub-codes "Failed to respect
Exclude Route" MAY take no action.
This mechanism can work with all the PKS resolution mechanisms,
as detailed in [RFC5553] section 3.1. A PCE, co-located or not,
may be used to resolve the PKS, but the node (i.e., a Label
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Switcher Router (LSR)) can also use the PKS information to index
a Path Segment previously supplied to it by the entity that
originated the PKS, for example the LSR that inserted the PKS in
the RRO or a management system.
2.2.3. Processing rules for the PAS TLVs
This section describes processing rules for the IPv4 and IPv6 PAS
TLVs.
An EN may include a PAS identifier in the PAS TLVs of the
diversity XRO subobject to convey diversity constraints. In order
to exclude multiple PAS identifiers, an EN may include multiple
diversity XRO subobjects each with a different PAS identifier.
How an EN determines the PAS identifier is a local matter for the
EN administrator. This identifier is a suggested identifier and
may be overridden by a CN under some conditions, regardless if L
bit is set or not. For example, a PAS identifier can be used with
no prior exchange of PAS information between the EN and the CN.
Upon reception of the PAS identifier information the CN can infer
the EN's requirements. The actual PAS identifier used will be
returned in the RESV message.
If the L-flag of the diversity XRO subobject is not set, the
processing node follows the following procedure:
- The processing node MUST ensure that any path calculated for
the signaled LSP respects the requested PAS exclusion,
including local resources.
- If the processing node fails to find a path that meets the
requested constraint, the processing node MUST return a PathErr
with the error code "Routing Problem" (24) and error sub-code
"Route blocked by Exclude Route" (67).
- If the PAS value referenced in the PAS TLV is unknown to the
processing node, the processing node MAY infer the diversity
requirement. After sending the Resv for the signaled LSP, the
processing node SHOULD return a PathErr with the error code
"Notify Error" (25) and error sub-code "XRO PAS value inferred"
(value to be assigned by IANA, suggested value: TBD). However,
if processing node fails to infer the diversity requirement
from PAS value, it MUST return a PathErr with the error code
"Routing Problem" (24) and error sub-code "Route blocked by
Exclude Route" (67).
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If the L-flag of the diversity XRO subobject is set, the
processing node follows the procedure below:
- The processing node SHOULD ensure that any path calculated for
the signaled LSP respects the requested PAS exclusion,
including local resources.
- If the processing node fails to find a path that meets the
requested constraint, it SHOULD proceed with signaling using a
suitable path that meets the constraint as far as possible.
After sending the Resv for the signaled LSP, it SHOULD return a
PathErr message with error code "Notify Error" (25) and error
sub-code "Failed to respect Exclude Route" (value: to be
assigned by IANA, suggest value: 14) to the source node.
- If the PAS value referenced in the PAS TLV is unknown to the
processing node, the processing node MAY infer the diversity
requirement. However, if processing node fails to infer the
diversity requirement it MAY ignore the PAS TLV in the
diversity XRO subobject of XRO and SHOULD proceed with the
signaling request. After sending the Resv for signaled LSP, the
processing node SHOULD return a PathErr message with the error
code "Notify Error" (25) and error sub-code "Failed to respect
Exclude Route" (value: to be assigned by IANA, suggest value:
14) to the source node.
In the context of VPN, upon reception of the PAS identifier
information, the CN looks up the CN based addresses in the
Provider Index Table (PIT). The CN also looks up the SRLG
information (or equivalent) in the core network that is
associated with LSPs belonging to the same Path Affinity Set and
exclude those resources from the path computation for this LSP.
The CN may alternatively choose from an existing path with a
disjoint set of resources.
Optionally the EN may use a value of all zeros in the PAS
identifier allowing the CN to select an appropriate PAS
identifier. Also the CN may to override the PAS identifier
allowing the CN to re-assign the identifier if required. An EN
should not assume that the PAS identifier used for setup is the
actual PAS identifier.
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2.2.3.1.1. Distribution of the Path Affinity Set Information
Information about TE link SRLGs is already available in the IGP
TE database. A core network can be designed to have additional
opaque records for core network paths that distribute EN paths,
PAS values associated with them and SRLG on a VPN basis. When a
core network path is setup, the following information allows a CN
to lookup the CN diversity information:
. L1 VPN Identifier
. Path Affinity Set Identifier
. Source CN Address
. Destination CN Address
. List of core network SRLGs (variable)
The source CN address and destination CN address are the same
addresses in the VPN PIT and correspond to the respective EN
address identifiers.
Note that all of the information is local to the CN context and
is not shared with the EN. The VPN Identifier is associated with
an EN. The only value that is signaled from the EN is the Path
Affinity Set and optionally the addresses of an existing LSP. The
CN stores source and destination CN addresses of the LSP in their
native format along with the SRLG information. This information
is internal to the core network and is assumed to be known.
2.3. Diversity EXRS Subobject
[RFC4874] defines the EXRS ERO subobject. An EXRS is used to
identify abstract nodes or resources that must not or should not
be used on the path between two inclusive abstract nodes or
resources in the explicit route. An EXRS contains one or more
subobjects of its own, called EXRS subobjects [RFC4874].
An EXRS MAY include Diversity subobject as specified in this
document. In this case, the EXRS format would be 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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|L| Type | Length | Reserved |
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+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|L| Type |Attribute Flags|Exclusion Flags| Reserved |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| TLVs ... |
// //
| |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
The meanings of respective fields in EXRS header are as defined
in [RFC4874]. The meanings of respective fields in Diversity
subobject are as defined earlier in this document.
The processing rules for the EXRS object are unchanged from
[RFC4874]. When the EXRS contains one or more Diversity
subobject(s), the processing rules specified in Section 2.3 apply
to the node processing the ERO with the EXRS subobject.
If a loose-hop expansion results in the creation of another
loose-hop in the outgoing ERO, the processing node MAY include
the EXRS in the newly created loose hop for further processing by
downstream nodes.
The processing node exception for the EXRS subobject applies to
the node processing the ERO.
The destination node exception for the EXRS subobject applies to
the explicit node identified by the ERO subobject that identifies
the next abstract node. This flag is only processed if the L bit
is set in the ERO subobject that identifies the next abstract
node.
The penultimate node exception for the EXRS subobject applies to
the node before the explicit node identified by the ERO subobject
that identifies the next abstract node. This flag is only
processed if the L bit is set in the ERO subobject that
identifies the next abstract node.
3. Security Considerations
This document does not introduce any additional security issues
above those identified in [RFC5920], [RFC2205], [RFC3209],
[RFC3473] and [RFC4874].
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4. IANA Considerations
4.1. New XRO subobject types
IANA registry: RSVP PARAMETERS
Subsection: Class Names, Class Numbers, and Class Types
This document introduces two new subobjects for the EXCLUDE_ROUTE
object [RFC4874], C-Type 1.
Subobject Description Subobject Type
--------------
---------------------
Diversity subobject To be assigned by IANA
(suggested value: 36)
4.2. New EXRS subobject types
The diversity XRO subobjects are also defined as new EXRS
subobjects.
4.3. TLV types for Diversity XRO and EXRS subobjects
The following TLV types for Diversity XRO and EXRS subobjects are
defined.
TLV Description TLV Type
--------------- --------
IPv4 Point-to-Point tunnel identifier To be assigned by IANA
(suggested value: 1)
IPv6 Point-to-Point tunnel identifier To be assigned by IANA
(suggested value: 2)
IPv4 Path Key To be assigned by IANA
(suggested value: 3)
IPv6 Path Key To be assigned by IANA
(suggested value: 4)
IPv4 Path Affinity Set
To be assigned by IANA
(suggested value: 5)
IPv6 Path Affinity Set
To be assigned by IANA
(suggested value: 6)
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4.4. New RSVP error sub-codes
IANA registry: RSVP PARAMETERS
Subsection: Error Codes and Globally Defined Error Value Sub-
Codes
For Error Code "Notify Error" (25) (see [RFC3209]) the following
sub-codes are defined.
Sub-code Value
-------- -----
Route of XRO To be assigned by IANA.
tunnel identifier unknown Suggested Value: 13.
Failed to respect Exclude Route To be assigned by IANA.
Suggested Value: 14.
Compliant path exists To be assigned by IANA.
Suggested Value: 15.
XRO PAS value inferred To be assigned by IANA.
Suggested Value: 16
5. Acknowledgements
The authors would like to thank Luyuan Fang and Walid Wakim for
their review comments.
6. References
6.1. Normative References
[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
Requirement Levels", BCP 14, RFC 2119, March 1997.
[RFC3209] Awduche, D., Berger, L., Gan, D., Li, T., Srinivasan,
V., and G. Swallow, "RSVP-TE: Extensions to RSVP for
LSP Tunnels", RFC 3209, December 2001.
[RFC3473] Berger, L., "Generalized Multi-Protocol Label Switching
(GMPLS) Signaling Resource ReserVation Protocol-Traffic
Engineering (RSVP-TE) Extensions", RFC 3473, January
2003.
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[RFC4874] Lee, CY., Farrel, A., and S. De Cnodder, "Exclude
Routes - Extension to Resource ReserVation Protocol-
Traffic Engineering (RSVP-TE)", RFC 4874, April 2007.
[RFC5553] Farrel, A., Ed., Bradford, R., and JP. Vasseur,
"Resource Reservation Protocol (RSVP) Extensions for Path Key
Support", RFC 5553, May 2009.
6.2. Informative References
[RFC4208] Swallow, G., Drake, J., Ishimatsu, H., and Y. Rekhter,
"Generalized Multiprotocol Label Switching (GMPLS)
User-Network Interface (UNI): Resource ReserVation
Protocol-Traffic Engineering (RSVP-TE) Support for the
Overlay Model", RFC 4208, October 2005.
[RFC4920] Farrel, A., Ed., Satyanarayana, A., Iwata, A., Fujita,
N., and G. Ash, "Crankback Signaling Extensions for
MPLS and GMPLS RSVP-TE", RFC 4920, July 2007.
[RFC5520] Bradford, R., Ed., Vasseur, JP., and A. Farrel,
"Preserving Topology Confidentiality in Inter-Domain
Path Computation Using a Path-Key-Based Mechanism", RFC
5520, April 2009.
[DRAFT-SRLG-RECORDING] F. Zhang, D. Li, O. Gonzalez de Dios, C.
Margaria, "RSVP-TE Extensions for Collecting SRLG
Information", draft-ietf-ccamp-rsvp-te-srlg-collect.txt,
work in progress.
[RFC2205] Braden, R. (Ed.), Zhang, L., Berson, S., Herzog, S. and
S. Jamin, "Resource ReserVation Protocol -- Version 1
Functional Specification", RFC 2205, September 1997.
[RFC4026] Andersson, L. and T. Madsen, "Provider Provisioned
Virtual Private Network (VPN) Terminology", RFC 4026,
March 2005.
[RFC5253] Takeda, T., Ed., "Applicability Statement for Layer 1
Virtual Private Network (L1VPN) Basic Mode", RFC 5253,
July 2008.
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[RFC5920] Fang, L., Ed., "Security Framework for MPLS and GMPLS
Networks", RFC 5920, July 2010.
Contributor's Addresses
Igor Bryskin
ADVA Optical Networking
Email: ibryskin@advaoptical.com
Daniele Ceccarelli
Ericsson
Email: Daniele.Ceccarelli@ericsson.com
Dhruv Dhody
Huawei Technologies
EMail: dhruv.ietf@gmail.com
Oscar Gonzalez de Dios
Telefonica I+D
Email: ogondio@tid.es
Don Fedyk
Hewlett-Packard
Email: don.fedyk@hp.com
Clarence Filsfils
Cisco Systems, Inc.
Email: cfilsfil@cisco.com
Xihua Fu
ZTE
Email: fu.xihua@zte.com.cn
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Gabriele Maria Galimberti
Cisco Systems
Email: ggalimbe@cisco.com
Ori Gerstel
SDN Solutions Ltd.
Email: origerstel@gmail.com
Matt Hartley
Cisco Systems
Email: mhartley@cisco.com
Kenji Kumaki
KDDI Corporation
Email: ke-kumaki@kddi.com
Rudiger Kunze
Deutsche Telekom AG
Email: Ruediger.Kunze@telekom.de
Lieven Levrau
Alcatel-Lucent
Email: Lieven.Levrau@alcatel-lucent.com
Cyril Margaria
cyril.margaria@gmail.com
Julien Meuric
France Telecom Orange
Email: julien.meuric@orange.com
Yuji Tochio
Fujitsu
Email: tochio@jp.fujitsu.com
Xian Zhang
Huawei Technologies
Email: zhang.xian@huawei.com
Authors' Addresses
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Zafar Ali
Cisco Systems.
Email: zali@cisco.com
Dieter Beller
Alcatel-Lucent
Email: Dieter.Beller@alcatel-lucent.com
George Swallow
Cisco Systems
Email: swallow@cisco.com
Fatai Zhang
Huawei Technologies
Email: zhangfatai@huawei.com
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