draft-ietf-pce-pcep-domain-sequence-06.txt   draft-ietf-pce-pcep-domain-sequence-07.txt 
PCE Working Group D. Dhody PCE Working Group D. Dhody
Internet-Draft U. Palle Internet-Draft U. Palle
Intended status: Experimental Huawei Technologies Intended status: Experimental Huawei Technologies
Expires: April 25, 2015 R. Casellas Expires: July 3, 2015 R. Casellas
CTTC CTTC
October 22, 2014 December 30, 2014
Standard Representation Of Domain-Sequence Standard Representation of Domain-Sequence
draft-ietf-pce-pcep-domain-sequence-06 draft-ietf-pce-pcep-domain-sequence-07
Abstract Abstract
The ability to compute shortest constrained Traffic Engineering Label The ability to compute shortest constrained Traffic Engineering Label
Switched Paths (TE LSPs) in Multiprotocol Label Switching (MPLS) and Switched Paths (TE LSPs) in Multiprotocol Label Switching (MPLS) and
Generalized MPLS (GMPLS) networks across multiple domains has been Generalized MPLS (GMPLS) networks across multiple domains has been
identified as a key requirement. In this context, a domain is a identified as a key requirement. In this context, a domain is a
collection of network elements within a common sphere of address collection of network elements within a common sphere of address
management or path computational responsibility such as an Interior management or path computational responsibility such as an Interior
Gateway Protocol (IGP) area or an Autonomous Systems (AS). This Gateway Protocol (IGP) area or an Autonomous System (AS). This
document specifies a standard representation and encoding of a document specifies a standard representation and encoding of a
Domain-Sequence, which is defined as an ordered sequence of domains Domain-Sequence, which is defined as an ordered sequence of domains
traversed to reach the destination domain to be used by Path traversed to reach the destination domain to be used by Path
Computation Elements (PCEs) to compute inter-domain shortest Computation Elements (PCEs) to compute inter-domain constrained
constrained paths across a predetermined sequence of domains . This shortest paths across a predetermined sequence of domains . This
document also defines new subobjects to be used to encode domain document also defines new subobjects to be used to encode domain
identifiers. identifiers.
Status of This Memo Status of This Memo
This Internet-Draft is submitted in full conformance with the This Internet-Draft is submitted in full conformance with the
provisions of BCP 78 and BCP 79. provisions of BCP 78 and BCP 79.
Internet-Drafts are working documents of the Internet Engineering Internet-Drafts are working documents of the Internet Engineering
Task Force (IETF). Note that other groups may also distribute Task Force (IETF). Note that other groups may also distribute
working documents as Internet-Drafts. The list of current Internet- working documents as Internet-Drafts. The list of current Internet-
Drafts is at http://datatracker.ietf.org/drafts/current/. Drafts is at http://datatracker.ietf.org/drafts/current/.
Internet-Drafts are draft documents valid for a maximum of six months Internet-Drafts are draft documents valid for a maximum of six months
and may be updated, replaced, or obsoleted by other documents at any and may be updated, replaced, or obsoleted by other documents at any
time. It is inappropriate to use Internet-Drafts as reference time. It is inappropriate to use Internet-Drafts as reference
material or to cite them other than as "work in progress." material or to cite them other than as "work in progress."
This Internet-Draft will expire on April 25, 2015. This Internet-Draft will expire on July 3, 2015.
Copyright Notice Copyright Notice
Copyright (c) 2014 IETF Trust and the persons identified as the Copyright (c) 2014 IETF Trust and the persons identified as the
document authors. All rights reserved. document authors. All rights reserved.
This document is subject to BCP 78 and the IETF Trust's Legal This document is subject to BCP 78 and the IETF Trust's Legal
Provisions Relating to IETF Documents Provisions Relating to IETF Documents
(http://trustee.ietf.org/license-info) in effect on the date of (http://trustee.ietf.org/license-info) in effect on the date of
publication of this document. Please review these documents publication of this document. Please review these documents
skipping to change at page 2, line 34 skipping to change at page 2, line 34
2. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . 4 2. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . 4
3. Detail Description . . . . . . . . . . . . . . . . . . . . . 5 3. Detail Description . . . . . . . . . . . . . . . . . . . . . 5
3.1. Domains . . . . . . . . . . . . . . . . . . . . . . . . . 5 3.1. Domains . . . . . . . . . . . . . . . . . . . . . . . . . 5
3.2. Domain-Sequence . . . . . . . . . . . . . . . . . . . . . 5 3.2. Domain-Sequence . . . . . . . . . . . . . . . . . . . . . 5
3.3. Standard Representation . . . . . . . . . . . . . . . . . 6 3.3. Standard Representation . . . . . . . . . . . . . . . . . 6
3.4. Include Route Object (IRO) . . . . . . . . . . . . . . . 7 3.4. Include Route Object (IRO) . . . . . . . . . . . . . . . 7
3.4.1. Subobjects . . . . . . . . . . . . . . . . . . . . . 7 3.4.1. Subobjects . . . . . . . . . . . . . . . . . . . . . 7
3.4.1.1. Autonomous system . . . . . . . . . . . . . . . . 8 3.4.1.1. Autonomous system . . . . . . . . . . . . . . . . 8
3.4.1.2. IGP Area . . . . . . . . . . . . . . . . . . . . 8 3.4.1.2. IGP Area . . . . . . . . . . . . . . . . . . . . 8
3.4.2. Update in IRO specification . . . . . . . . . . . . . 9 3.4.2. Update in IRO specification . . . . . . . . . . . . . 9
3.4.3. IRO for domain-sequence . . . . . . . . . . . . . . . 10 3.4.3. IRO for Domain-Sequence . . . . . . . . . . . . . . . 10
3.5. Exclude Route Object (XRO) . . . . . . . . . . . . . . . 11 3.5. Exclude Route Object (XRO) . . . . . . . . . . . . . . . 11
3.5.1. Subobjects . . . . . . . . . . . . . . . . . . . . . 12 3.5.1. Subobjects . . . . . . . . . . . . . . . . . . . . . 12
3.5.1.1. Autonomous system . . . . . . . . . . . . . . . . 12 3.5.1.1. Autonomous system . . . . . . . . . . . . . . . . 12
3.5.1.2. IGP Area . . . . . . . . . . . . . . . . . . . . 13 3.5.1.2. IGP Area . . . . . . . . . . . . . . . . . . . . 13
3.6. Explicit Exclusion Route Subobject (EXRS) . . . . . . . . 14 3.6. Explicit Exclusion Route Subobject (EXRS) . . . . . . . . 14
3.7. Explicit Route Object (ERO) . . . . . . . . . . . . . . . 14 3.7. Explicit Route Object (ERO) . . . . . . . . . . . . . . . 14
4. Other Considerations . . . . . . . . . . . . . . . . . . . . 15 4. Other Considerations . . . . . . . . . . . . . . . . . . . . 15
4.1. Inter-Area Path Computation . . . . . . . . . . . . . . . 15 4.1. Inter-Area Path Computation . . . . . . . . . . . . . . . 15
4.2. Inter-AS Path Computation . . . . . . . . . . . . . . . . 17 4.2. Inter-AS Path Computation . . . . . . . . . . . . . . . . 17
4.2.1. Example 1 . . . . . . . . . . . . . . . . . . . . . . 17 4.2.1. Example 1 . . . . . . . . . . . . . . . . . . . . . . 17
skipping to change at page 3, line 23 skipping to change at page 3, line 23
7.6. Impact On Network Operations . . . . . . . . . . . . . . 27 7.6. Impact On Network Operations . . . . . . . . . . . . . . 27
8. Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . 27 8. Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . 27
9. References . . . . . . . . . . . . . . . . . . . . . . . . . 27 9. References . . . . . . . . . . . . . . . . . . . . . . . . . 27
9.1. Normative References . . . . . . . . . . . . . . . . . . 27 9.1. Normative References . . . . . . . . . . . . . . . . . . 27
9.2. Informative References . . . . . . . . . . . . . . . . . 27 9.2. Informative References . . . . . . . . . . . . . . . . . 27
1. Introduction 1. Introduction
A PCE may be used to compute end-to-end paths across multi-domain A PCE may be used to compute end-to-end paths across multi-domain
environments using a per-domain path computation technique [RFC5152]. environments using a per-domain path computation technique [RFC5152].
The so called backward recursive path computation (BRPC) mechanism The backward recursive path computation (BRPC) mechanism [RFC5441]
[RFC5441] defines a PCE-based path computation procedure to compute also defines a PCE-based path computation procedure to compute inter-
inter-domain constrained (G)MPLS TE LSPs. However, both per-domain domain constrained path for (G)MPLS TE LSPs. However, both per-
and BRPC techniques assume that the sequence of domains to be crossed domain and BRPC techniques assume that the sequence of domains to be
from source to destination is known, either fixed by the network crossed from source to destination is known, either fixed by the
operator or obtained by other means. Also for inter-domain point-to- network operator or obtained by other means. Also for inter-domain
multi-point (P2MP) tree computation, [RFC7334] assumes the domain- point-to-multi-point (P2MP) tree computation, [RFC7334] assumes the
tree is known in priori. domain-tree is known in priori.
The list of domains (domain-sequence) in a point-to-point (P2P) path The list of domains (Domain-Sequence) in point-to-point (P2P) or a
or a point-to-multipoint (P2MP) tree is usually a constraint in the domain tree in point-to-multipoint (P2MP) is usually a constraint in
path computation request. A PCE determines the next PCE to forward inter-domain path computation procedure. A PCE determines the next
the request based on the domain-sequence. In a multi-domain path PCE to forward the request based on the Domain-Sequence. In a multi-
computation, a PCC MAY indicate the sequence of domains to be domain path computation, a Path Computation Client (PCC) MAY indicate
traversed using the Include Route Object (IRO) defined in [RFC5440]. the sequence of domains to be traversed using the Include Route
Object (IRO) defined in [RFC5440].
When the sequence of domains is not known in advance, the When the sequence of domains is not known in advance, the
Hierarchical PCE (H-PCE) [RFC6805] architecture and mechanisms can be Hierarchical PCE (H-PCE) [RFC6805] architecture and mechanisms can be
used to determine the end-to-end Domain-Sequence. used to determine the Domain-Sequence.
This document defines a standard way to represent and encode a This document defines a standard way to represent and encode a
Domain-Sequence in various deployment scenarios including P2P, P2MP Domain-Sequence in various scenarios including P2P LSP, P2MP LSP, and
and H-PCE. use of H-PCE.
The Domain-Sequence (the set of domains traversed to reach the The Domain-Sequence (the set of domains traversed to reach the
destination domain) is either administratively predetermined or destination domain) is either administratively predetermined or
discovered by some means (H-PCE) that is outside of the scope of this discovered by some means like H-PCE.
document.
[RFC5440] defines the Include Route Object (IRO) and the Explicit [RFC5440] defines the Include Route Object (IRO) and the Explicit
Route Object (ERO); [RFC5521] defines the Exclude Route Object (XRO) Route Object (ERO). [RFC5521] defines the Exclude Route Object (XRO)
and the Explicit Exclusion Route Subobject (EXRS); The use of and the Explicit Exclusion Route Subobject (EXRS). The use of
Autonomous System (AS) (albeit with a 2-Byte AS number) as an Autonomous System (AS) (albeit with a 2-Byte AS number) as an
abstract node representing domain is defined in [RFC3209], this abstract node representing a domain is defined in [RFC3209], this
document specifies new subobjects to include or exclude domains such document specifies new subobjects to include or exclude domains
as an IGP area or an Autonomous Systems (4-Byte as per [RFC4893]). including IGP area or an Autonomous Systems (4-Byte as per
[RFC6793]).
Further, the domain identifier may simply act as delimiter to specify Further, the domain identifier may simply act as delimiter to specify
where the domain boundary starts and ends. where the domain boundary starts and ends in some cases.
This is a companion document to Resource ReserVation Protocol - This is a companion document to Resource ReserVation Protocol -
Traffic Engineering (RSVP-TE) extensions for the domain identifiers Traffic Engineering (RSVP-TE) extensions for the domain identifiers
[DOMAIN-SUBOBJ]. [DOMAIN-SUBOBJ].
1.1. Requirements Language 1.1. Requirements Language
The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
"SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this
document are to be interpreted as described in [RFC2119]. document are to be interpreted as described in [RFC2119].
skipping to change at page 4, line 44 skipping to change at page 4, line 45
ASBR: Autonomous System Boundary Router. ASBR: Autonomous System Boundary Router.
BN: Boundary Node, Can be an ABR or ASBR. BN: Boundary Node, Can be an ABR or ASBR.
BRPC: Backward Recursive Path Computation BRPC: Backward Recursive Path Computation
Domain: As per [RFC4655], any collection of network elements within Domain: As per [RFC4655], any collection of network elements within
a common sphere of address management or path computational a common sphere of address management or path computational
responsibility. Examples of domains include Interior Gateway responsibility. Examples of domains include Interior Gateway
Protocol (IGP) areas and Autonomous Systems (ASs). Protocol (IGP) area and Autonomous System (AS).
Domain-Sequence: An ordered sequence of domains traversed to reach Domain-Sequence: An ordered sequence of domains traversed to reach
the destination domain. the destination domain.
ERO: Explicit Route Object ERO: Explicit Route Object
H-PCE: Hierarchical PCE H-PCE: Hierarchical PCE
IGP: Interior Gateway Protocol. Either of the two routing IGP: Interior Gateway Protocol. Either of the two routing
protocols, Open Shortest Path First (OSPF) or Intermediate System protocols, Open Shortest Path First (OSPF) or Intermediate System
to Intermediate System (IS-IS). to Intermediate System (IS-IS).
skipping to change at page 5, line 43 skipping to change at page 5, line 43
3.1. Domains 3.1. Domains
[RFC4726] and [RFC4655] define domain as a separate administrative or [RFC4726] and [RFC4655] define domain as a separate administrative or
geographic environment within the network. A domain may be further geographic environment within the network. A domain may be further
defined as a zone of routing or computational ability. Under these defined as a zone of routing or computational ability. Under these
definitions a domain might be categorized as an AS or an IGP area. definitions a domain might be categorized as an AS or an IGP area.
Each AS can be made of several IGP areas. In order to encode a Each AS can be made of several IGP areas. In order to encode a
Domain-Sequence, it is required to uniquely identify a domain in the Domain-Sequence, it is required to uniquely identify a domain in the
Domain-Sequence. A domain can be uniquely identified by area-id or Domain-Sequence. A domain can be uniquely identified by area-id or
AS or both. AS number or both.
3.2. Domain-Sequence 3.2. Domain-Sequence
A domain-sequence is an ordered sequence of domains traversed to A Domain-Sequence is an ordered sequence of domains traversed to
reach the destination domain. reach the destination domain.
A domain-sequence can be applied as a constraint and carried in path A Domain-Sequence can be applied as a constraint and carried in a
computation request to PCE(s). A domain-sequence can also be the path computation request to PCE(s). A Domain-Sequence can also be
result of a path computation. For example, in the case of H-PCE the result of a path computation. For example, in the case of H-PCE
[RFC6805] Parent PCE MAY send the Domain-Sequence as a result in a [RFC6805] Parent PCE MAY send the Domain-Sequence as a result in a
path computation reply. path computation reply.
In a P2P path, the domains listed appear in the order that they are In a P2P path, the domains listed appear in the order that they are
crossed. In a P2MP path, the domain tree is represented as list of crossed. In a P2MP path, the domain tree is represented as a list of
domain sequences. Domain-Sequences.
A domain-sequence enables a PCE to select the next PCE to forward the A Domain-Sequence enables a PCE to select the next domain and the PCE
path computation request based on the domain information. serving that domain to forward the path computation request based on
the domain information.
A PCC or PCE MAY add an additional constraints covering which A PCC or PCE MAY add an additional constraint covering which Boundary
Boundary Nodes (ABR or ASBR) or Border links (Inter-AS-link) MUST be Nodes (ABR or ASBR) or Border links (Inter-AS-links) MUST be
traversed while defining a Domain-Sequence. traversed while defining a Domain-Sequence.
Thus a Domain-Sequence MAY be made up of one or more of - Thus a Domain-Sequence MAY be made up of one or more of -
o AS Number o AS Number
o Area ID o Area ID
o Boundary Node ID o Boundary Node ID
o Inter-AS-Link Address o Inter-AS-Link Address
Consequently, a Domain-Sequence can be used: Consequently, a Domain-Sequence can be used:
1. by a PCE in order to discover or select the next PCE in a 1. by a PCE in order to discover or select the next PCE in a
collaborative path computation, such as in BRPC [RFC5441]; collaborative path computation, such as in BRPC [RFC5441];
2. by the Parent PCE to return the Domain-Sequence when unknown, 2. by the Parent PCE to return the Domain-Sequence when unknown;
this can further be an input to BRPC procedure [RFC6805]; this can then be an input to the BRPC procedure [RFC6805];
3. by a PCC (or PCE) to constraint the domains used in a H-PCE path 3. by a PCC (or PCE) to constraint the domains used in a H-PCE path
computation, explicitly specifying which domains to be expanded; computation, explicitly specifying which domains to be expanded;
4. by a PCE in per-domain path computation model [RFC5152] to 4. by a PCE in the per-domain path computation model [RFC5152] to
identify the next domain(s); identify the next domain;
3.3. Standard Representation 3.3. Standard Representation
Domain-Sequence MAY appear in PCEP Messages, notably in - Domain-Sequence MAY appear in PCEP messages, notably in -
o Include Route Object (IRO): As per [RFC5440], used to specify set o Include Route Object (IRO): As per [RFC5440], used to specify set
of network elements that MUST be traversed. The subobjects in IRO of network elements that MUST be traversed. The subobjects in IRO
are used to specify the domain-sequence that MUST be traversed to are used to specify the Domain-Sequence that MUST be traversed to
reach the destination. reach the destination.
o Exclude Route Object (XRO): As per [RFC5521], used to specify o Exclude Route Object (XRO): As per [RFC5521], used to specify
certain abstract nodes that MUST be excluded from whole path. The certain abstract nodes that MUST be excluded from whole path. The
subobjects in XRO are used to specify certain domains that MUST be subobjects in XRO are used to specify certain domains that MUST be
avoided to reach the destination. avoided to reach the destination.
o Explicit Exclusion Route Subobject (EXRS): As per [RFC5521], used o Explicit Exclusion Route Subobject (EXRS): As per [RFC5521], used
to specify exclusion of certain abstract nodes between a specific to specify exclusion of certain abstract nodes between a specific
pair of nodes. EXRS are a subobject inside the IRO. These pair of nodes. EXRS are a subobject inside the IRO. These
subobjects are used to specify the domains that must be excluded subobjects are used to specify the domains that must be excluded
between two abstract nodes. between two abstract nodes.
o Explicit Route Object (ERO): As per [RFC5440], used to specify a o Explicit Route Object (ERO): As per [RFC5440], used to specify a
computed path in the network. For example, in the case of H-PCE computed path in the network. For example, in the case of H-PCE
[RFC6805] Parent PCE MAY send the Domain-Sequence as a result in a [RFC6805], a Parent PCE MAY send the Domain-Sequence as a result
path computation reply using ERO. in a path computation reply using ERO.
3.4. Include Route Object (IRO) 3.4. Include Route Object (IRO)
As per [RFC5440], IRO (Include Route Object) can be used to specify As per [RFC5440], IRO (Include Route Object) can be used to specify
that the computed path MUST traverse a set of specified network that the computed path MUST traverse a set of specified network
elements or abstract nodes. elements or abstract nodes.
3.4.1. Subobjects 3.4.1. Subobjects
Some subobjects are defined in [RFC3209], [RFC3473], [RFC3477] and Some subobjects are defined in [RFC3209], [RFC3473], [RFC3477] and
skipping to change at page 8, line 9 skipping to change at page 8, line 9
Type Subobject Type Subobject
TBD1 Autonomous system number (4 Byte) TBD1 Autonomous system number (4 Byte)
TBD2 OSPF Area id TBD2 OSPF Area id
TBD3 ISIS Area id TBD3 ISIS Area id
3.4.1.1. Autonomous system 3.4.1.1. Autonomous system
[RFC3209] already defines 2 byte AS number. [RFC3209] already defines 2 byte AS number.
To support 4 byte AS number as per [RFC4893] following subobject is To support 4 byte AS number as per [RFC6793] following subobject is
defined: defined:
0 1 2 3 0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 0 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 | |L| Type | Length | Reserved |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| AS-ID (4 bytes) | | AS-ID (4 bytes) |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
skipping to change at page 9, line 48 skipping to change at page 9, line 48
Reserved: Zero at transmission, ignored at receipt. Reserved: Zero at transmission, ignored at receipt.
IS-IS Area Id: The variable-length IS-IS area identifier. Padded IS-IS Area Id: The variable-length IS-IS area identifier. Padded
with trailing zeroes to a four-byte boundary. with trailing zeroes to a four-byte boundary.
3.4.2. Update in IRO specification 3.4.2. Update in IRO specification
[RFC5440] describes IRO as an optional object used to specify that [RFC5440] describes IRO as an optional object used to specify that
the computed path MUST traverse a set of specified network elements. the computed path MUST traverse a set of specified network elements.
It further state that the L bit of such sub-object has no meaning It further state that the L bit of such subobject has no meaning
within an IRO. It did not mention if IRO is an ordered or un-ordered within an IRO. It did not mention if IRO is an ordered or un-ordered
list of sub-objects. list of subobjects.
An update to IRO specification [IRO-UPDATE] makes IRO as an ordered An update to IRO specification [IRO-UPDATE] makes IRO as an ordered
list as well as support for loose bit (L-bit). list as well as support for loose bit (L-bit).
The use IRO for domain-sequence assumes the updated specification for The use IRO for Domain-Sequence assumes the updated specification for
IRO as per [IRO-UPDATE]. IRO as per [IRO-UPDATE].
3.4.3. IRO for domain-sequence 3.4.3. IRO for Domain-Sequence
Some subobjects for IRO are defined in [RFC3209], [RFC3473], Some subobjects for the IRO are defined in [RFC3209], [RFC3473],
[RFC3477] and [RFC4874], further some new subobjects related to [RFC3477], and [RFC4874]; further some new subobjects related to
Domain-Sequence are also added in this document as mentioned in Domain-Sequence are also added in this document as mentioned in
Section 3.4. Section 3.4.
The subobjects for IPv4, IPv6 and unnumbered Interface ID can be used The subobject type for IPv4, IPv6, and unnumbered Interface ID can be
to specify Boundary Node (ABR/ASBR) and Inter-AS-Links. The used to specify Boundary Nodes (ABR/ASBR) and Inter-AS-Links. The
subobjects for AS Number (2 or 4 Byte) and IGP Area is used to subobject type for the AS Number (2 or 4 Byte) and the IGP Area are
specify the domain identifiers in the domain-sequence. used to specify the domain identifiers in the Domain-Sequence.
The IRO MAY have both intra-domain (from the context of the ingress The IRO MAY have both intra-domain (from the context of the ingress
PCC) and inter-domain (domain-sequence) subobjects in a sequence in PCC) and inter-domain (Domain-Sequence) subobjects in a sequence in
which they must be traversed in the computed path. which they must be traversed in the computed path.
Thus an IRO comprising of subobjects that represents a domain- Thus an IRO, comprising of subobjects that represents a Domain-
sequence may constraints or define the domains involved in an inter- Sequence, define the domains involved in an inter-domain path
domain path computation, typically involving two or more computation, typically involving two or more collaborative PCEs.
collaborative PCEs.
A Domain-Sequence can have varying degrees of granularity; it is A Domain-Sequence can have varying degrees of granularity. It is
possible to have a Domain-Sequence composed of, uniquely, AS possible to have a Domain-Sequence composed of, uniquely, AS
identifiers. It is also possible to list the involved areas for a identifiers. It is also possible to list the involved IGP areas for
given AS. a given AS.
In any case, the mapping between domains and responsible PCEs is not In any case, the mapping between domains and responsible PCEs is not
defined in this document. It is assumed that a PCE that needs to defined in this document. It is assumed that a PCE that needs to
obtain a "next PCE" from a Domain-Sequence is able to do so (e.g. via obtain a "next PCE" from a Domain-Sequence is able to do so (e.g. via
administrative configuration, or discovery). administrative configuration, or discovery).
A PCC builds an IRO to encode the Domain-Sequence, that the A PCC builds an IRO to encode the Domain-Sequence, so that the
cooperating PCEs should compute an inter-domain shortest constrained cooperating PCEs should compute an inter-domain shortest constrained
paths across the specified sequence of domains. path across the specified sequence of domains.
For each inclusion, the PCC clears the L-bit to indicate that the PCE For each inclusion, the PCC clears the L-bit to indicate that the PCE
is required to include the domain, or sets the L-bit to indicate that is required to include the domain, or sets the L-bit to indicate that
the PCC simply desires that the domain be included in the domain- the PCC simply desires that the domain be included in the Domain-
sequence. Sequence.
If a PCE encounters a subobject that it does not support or If a PCE encounters a subobject that it does not support or
recognize, it MUST act according to the setting of the L-bit in the recognize, it MUST act according to the setting of the L-bit in the
subobject. If the L-bit is clear, the PCE MUST respond with a PCErr subobject. If the L-bit is clear, the PCE MUST respond with a PCErr
with Error-Type TBD4 "Unrecognized subobject" and set the Error-Value with Error-Type TBD4 "Unrecognized subobject" and set the Error-Value
to the subobject type code. If the L-bit is set, the PCE MAY respond to the subobject type code. If the L-bit is set, the PCE MAY respond
with a PCErr as already stated or MAY ignore the subobject: this with a PCErr as already stated or MAY ignore the subobject: this
choice is a local policy decision. choice is a local policy decision.
PCE MUST act according to the requirements expressed in the PCE MUST act according to the requirements expressed in the
subobject. That is, if the L-bit is clear, the PCE(s) MUST produce a subobject. That is, if the L-bit is clear, the PCE(s) MUST produce a
path that follows domain-sequence nodes in order identified by the path that follows the Domain-Sequence in order identified by the
subobjects in the path. If the L-bit is set, the PCE(s) SHOULD subobjects in the path. If the L-bit is set, the PCE(s) SHOULD
produce a path along the Domain-Sequence unless it is not possible to produce a path along the Domain-Sequence unless it is not possible to
construct a path complying with the other constraints expressed in construct a path complying with the other constraints expressed in
the request. the request.
A successful path computation reported in a PCEP reply message A successful path computation reported in a path computation reply
(PCRep) MUST include an ERO to specify the path that has been message (PCRep) MUST include an ERO to specify the path that has been
computed as specified in [RFC5440] following the sequence of domains. computed as specified in [RFC5440] following the sequence of domains.
In a PCRep, PCE MAY also supply IRO (with domain sequence In a PCRep, PCE MAY also supply IRO (with Domain-Sequence
information) with the NO-PATH object indicating that the set of information) with the NO-PATH object indicating that the set of
elements (domains) of the request's IRO prevented the PCEs from elements (domains) of the request's IRO prevented the PCEs from
finding a path. finding a path.
The Subobject types for domains (AS and IGP Area) affect the next Selection of the next domain and the PCE serving that domain is
domain selection as well as finding the PCE serving that domain. dependent on the domain subobjects (AS and IGP area) in the IRO.
Note that a particular domain in the domain-sequence can be Note that a particular domain in the Domain-Sequence can be
identified by :- identified by :-
o A single IGP Area: Only the IGP (OSPF or ISIS) Area subobject is o A single IGP Area: Only the IGP (OSPF or ISIS) Area subobject is
used to identify the next domain. (Refer Figure 1) used to identify the next domain. (Refer Figure 1)
o A single AS: Only the AS subobject is used to identify the next o A single AS: Only the AS subobject is used to identify the next
domain. (Refer Figure 2) domain. (Refer Figure 2)
o Both an AS and an IGP Area: Combination of both AS and Area are o Both an AS and an IGP Area: AS and Area in combination are used to
used to identify the next domain. In this case the order is AS identify the next domain. In this case the order is AS Subobject
Subobject followed by Area. (Refer Figure 3) followed by Area. (Refer Figure 3)
The Subobjects representing an internal node, a Boundary Node or an The Subobjects representing an internal node, a Boundary Node or an
Inter-AS-Link MAY influence the selection of the path as well. Inter-AS-Link MAY also influence the selection of the path.
3.5. Exclude Route Object (XRO) 3.5. Exclude Route Object (XRO)
The Exclude Route Object (XRO) [RFC5521] is an optional object used The Exclude Route Object (XRO) [RFC5521] is an optional object used
to specify exclusion of certain abstract nodes or resources from the to specify exclusion of certain abstract nodes or resources from the
whole path. whole path.
3.5.1. Subobjects 3.5.1. Subobjects
The following subobject types are defined to be used in XRO as The following subobject types are defined to be used in XRO as
skipping to change at page 15, line 31 skipping to change at page 15, line 31
TBD2 OSPF Area id TBD2 OSPF Area id
TBD3 ISIS Area id TBD3 ISIS Area id
The new subobjects to support 4 byte AS and IGP (OSPF / ISIS) Area The new subobjects to support 4 byte AS and IGP (OSPF / ISIS) Area
MAY also be used in the ERO to specify an abstract node (a group of MAY also be used in the ERO to specify an abstract node (a group of
nodes whose internal topology is opaque to the ingress node of the nodes whose internal topology is opaque to the ingress node of the
LSP). Using this concept of abstraction, an explicitly routed LSP LSP). Using this concept of abstraction, an explicitly routed LSP
can be specified as a sequence of domains. can be specified as a sequence of domains.
In case of Hierarchical PCE [RFC6805], a Parent PCE MAY be requested In case of Hierarchical PCE [RFC6805], a Parent PCE MAY be requested
to find the domain-sequence. Refer example in Section 4.6. to find the Domain-Sequence. Refer example in Section 4.6.
The format of the new ERO subobjects is similar to new IRO The format of the new ERO subobjects is similar to new IRO
subobjects, refer Section 3.4. subobjects, refer Section 3.4.
4. Other Considerations 4. Other Considerations
The examples in this section are for illustration purposes only; to The examples in this section are for illustration purposes only; to
show how the new subobjects may be encoded. highlight how the new subobjects may be encoded.
4.1. Inter-Area Path Computation 4.1. Inter-Area Path Computation
In an inter-area path computation where the ingress and the egress In an inter-area path computation where the ingress and the egress
nodes belong to different IGP areas within the same AS, the Domain- nodes belong to different IGP areas within the same AS, the Domain-
Sequence MAY be represented using a ordered list of Area subobjects. Sequence MAY be represented using a ordered list of Area subobjects.
The AS number MAY be skipped, as area information is enough to select The AS number MAY be skipped, as area information is enough to select
the next PCE. the next PCE.
+-------------------+ +-------------------+ +-------------------+ +-------------------+
skipping to change at page 19, line 27 skipping to change at page 19, line 27
| | | | | | | | | | | | | | | | | | | |
| | | | | | | | | | | | | | | | | | | |
+---------+ +---------+ +---------+ +---------+ +---------+ +---------+ +---------+ +---------+ +---------+ +---------+
Area subobject is optional and it MAY be skipped. PCE should be able Area subobject is optional and it MAY be skipped. PCE should be able
to understand both notations. to understand both notations.
4.2.2. Example 2 4.2.2. Example 2
As shown in Figure 3, where AS 200 is made up of multiple areas and As shown in Figure 3, where AS 200 is made up of multiple areas and
multiple domain-sequence exist, PCE MAY include both AS and Area multiple Domain-Sequence exist, PCE MAY include both AS and Area
subobject to uniquely identify the next domain and PCE. subobject to uniquely identify the next domain and PCE.
| |
| +-------------+ +----------------+ | +-------------+ +----------------+
| |Area 2 | |Area 4 | | |Area 2 | |Area 4 |
| | +--+| | +--+ | | | +--+| | +--+ |
| | | || | | | | | | | || | | | |
| | +--+ +--+| | +--+ +--+ | | | +--+ +--+| | +--+ +--+ |
| | | | | | | | | | | | | | | | | |
| | *--+ | | +--+ | | | *--+ | | +--+ |
skipping to change at page 21, line 15 skipping to change at page 21, line 15
If the area information cannot be provided, PCE MAY forward the path If the area information cannot be provided, PCE MAY forward the path
computation request to the next PCE based on AS alone. If multiple computation request to the next PCE based on AS alone. If multiple
PCEs are responsible, PCE MAY apply local policy to select the next PCEs are responsible, PCE MAY apply local policy to select the next
PCE. PCE.
4.3. Boundary Node and Inter-AS-Link 4.3. Boundary Node and Inter-AS-Link
A PCC or PCE MAY add additional constraints covering which Boundary A PCC or PCE MAY add additional constraints covering which Boundary
Nodes (ABR or ASBR) or Border links (Inter-AS-link) MUST be traversed Nodes (ABR or ASBR) or Border links (Inter-AS-link) MUST be traversed
while defining a Domain-Sequence. In which case the Boundary Node or while defining a Domain-Sequence. In which case the Boundary Node or
Link MAY be encoded as a part of the domain-sequence using the Link MAY be encoded as a part of the Domain-Sequence using the
existing subobjects. existing subobjects.
Boundary Nodes (ABR / ASBR) can be encoded using the IPv4 or IPv6 Boundary Nodes (ABR / ASBR) can be encoded using the IPv4 or IPv6
prefix subobjects usually the loopback address of 32 and 128 prefix prefix subobjects usually the loopback address of 32 and 128 prefix
length respectively. An Inter-AS link can be encoded using the IPv4 length respectively. An Inter-AS link can be encoded using the IPv4
or IPv6 prefix subobjects or unnumbered interface subobjects. or IPv6 prefix subobjects or unnumbered interface subobjects.
For Figure 1, an ABR to be traversed can be specified as: For Figure 1, an ABR to be traversed can be specified as:
+---------+ +---------+ +---------++---------+ +---------+ +---------+ +---------+ +---------++---------+ +---------+
skipping to change at page 22, line 8 skipping to change at page 22, line 8
4.4. PCE Serving multiple Domains 4.4. PCE Serving multiple Domains
A single PCE MAY be responsible for multiple domains; for example PCE A single PCE MAY be responsible for multiple domains; for example PCE
function deployed on an ABR. A PCE which can support 2 adjacent function deployed on an ABR. A PCE which can support 2 adjacent
domains can internally handle this situation without any impact on domains can internally handle this situation without any impact on
the neighbouring domains. the neighbouring domains.
4.5. P2MP 4.5. P2MP
In case of inter-domain P2MP path computation, (Refer [RFC7334]) the In case of inter-domain P2MP path computation, (Refer [RFC7334]) the
path domain tree is nothing but a series of Domain Sequences, as path domain tree is nothing but a series of Domain-Sequences, as
shown in the below figure: shown in the below figure:
D1-D3-D6, D1-D3-D5 and D1-D2-D4. D1-D3-D6, D1-D3-D5 and D1-D2-D4.
D1 D1
/ \ / \
D2 D3 D2 D3
/ / \ / / \
D4 D5 D6 D4 D5 D6
All rules of processing as applied to P2P can be applied to P2MP as All rules of processing as applied to P2P can be applied to P2MP as
well. well.
In case of P2MP, different destinations MAY have different Domain- In case of P2MP, different destinations MAY have different Domain-
Sequence within the domain tree, it requires domain-sequence to be Sequence within the domain tree, it requires Domain-Sequence to be
attached per destination. (Refer [PCE-P2MP-PER-DEST]) attached per destination. (Refer [PCE-P2MP-PER-DEST])
4.6. Hierarchical PCE 4.6. Hierarchical PCE
As per [RFC6805], consider a case as shown in Figure 4 consisting of As per [RFC6805], consider a case as shown in Figure 4 consisting of
multiple child PCEs and a parent PCE. multiple child PCEs and a parent PCE.
+--------+ +--------+
| Parent | | Parent |
| PCE | | PCE |
skipping to change at page 24, line 29 skipping to change at page 24, line 29
+---------+ +---------+ +---------+ +---------+ +---------+ +---------+ +---------+ +---------+ +---------+ +---------+
|ERO | |Sub | |Sub | |Sub | |Sub | |ERO | |Sub | |Sub | |Sub | |Sub |
|Object | |Object AS| |Object | |Object | |Object | |Object | |Object AS| |Object | |Object | |Object |
|Header | |100 | |Area 2 | |Area 0 | |Area 4 | |Header | |100 | |Area 2 | |Area 0 | |Area 4 |
| | | | | | | | | | | | | | | | | | | |
| | | | | | | | | | | | | | | | | | | |
+---------+ +---------+ +---------+ +---------+ +---------+ +---------+ +---------+ +---------+ +---------+ +---------+
4.7. Relationship to PCE Sequence 4.7. Relationship to PCE Sequence
Instead of a domain-sequence, a sequence of PCEs MAY be enforced by Instead of a Domain-Sequence, a sequence of PCEs MAY be enforced by
policy on the PCC, and this constraint can be carried in the PCReq policy on the PCC, and this constraint can be carried in the PCReq
message (as defined in [RFC5886]). message (as defined in [RFC5886]).
Note that PCE-Sequence can be used along with domain-sequence in Note that PCE-Sequence can be used along with Domain-Sequence in
which case PCE-Sequence SHOULD have higher precedence in selecting which case PCE-Sequence SHOULD have higher precedence in selecting
the next PCE in the inter-domain path computation procedures. Note the next PCE in the inter-domain path computation procedures. Note
that Domain-Sequence IRO constraints should still be checked as per that Domain-Sequence IRO constraints should still be checked as per
the rules of processing IRO. the rules of processing IRO.
4.8. Relationship to RSVP-TE 4.8. Relationship to RSVP-TE
[RFC3209] already describes the notion of abstract nodes, where an [RFC3209] already describes the notion of abstract nodes, where an
abstract node is a group of nodes whose internal topology is opaque abstract node is a group of nodes whose internal topology is opaque
to the ingress node of the LSP. It further defines a subobject for to the ingress node of the LSP. It further defines a subobject for
skipping to change at page 26, line 20 skipping to change at page 26, line 20
the exact behavior with regard to desired inclusion and exclusion of the exact behavior with regard to desired inclusion and exclusion of
domains must be available for examination by an operator and may be domains must be available for examination by an operator and may be
configurable. Second, the behavior on receipt of an unrecognized configurable. Second, the behavior on receipt of an unrecognized
subobjects with the L or X-bit set should be configurable and must be subobjects with the L or X-bit set should be configurable and must be
available for inspection. The inspection and control of these local available for inspection. The inspection and control of these local
policy choices may be part of the PCEP MIB module. policy choices may be part of the PCEP MIB module.
7.2. Information and Data Models 7.2. Information and Data Models
A MIB module for management of the PCEP is being specified in a A MIB module for management of the PCEP is being specified in a
separate document [PCEP-MIB]. That MIB module allows examination of separate document [RFC7420]. That MIB module allows examination of
individual PCEP messages, in particular requests, responses and individual PCEP messages, in particular requests, responses and
errors. The MIB module MUST be extended to include the ability to errors. The MIB module MUST be extended to include the ability to
view the domain-sequence extensions defined in this document. view the Domain-Sequence extensions defined in this document.
7.3. Liveness Detection and Monitoring 7.3. Liveness Detection and Monitoring
Mechanisms defined in this document do not imply any new liveness Mechanisms defined in this document do not imply any new liveness
detection and monitoring requirements in addition to those already detection and monitoring requirements in addition to those already
listed in [RFC5440]. listed in [RFC5440].
7.4. Verify Correct Operations 7.4. Verify Correct Operations
Mechanisms defined in this document do not imply any new operation Mechanisms defined in this document do not imply any new operation
verification requirements in addition to those already listed in verification requirements in addition to those already listed in
[RFC5440]. [RFC5440].
7.5. Requirements On Other Protocols 7.5. Requirements On Other Protocols
In case of per-domain path computation [RFC5152], where the full path In case of per-domain path computation [RFC5152], where the full path
of an inter-domain TE LSP cannot be or is not determined at the of an inter-domain TE LSP cannot be, or is not determined at the
ingress node, and signaling message may use domain identifiers. The ingress node, a signaling message may use the domain identifiers.
Subobjects defined in this document SHOULD be supported by RSVP-TE. The Subobjects defined in this document SHOULD be supported by RSVP-
[DOMAIN-SUBOBJ] extends the notion of abstract nodes by adding new TE. [DOMAIN-SUBOBJ] extends the notion of abstract nodes by adding
subobjects for IGP Areas and 4-byte AS numbers. new subobjects for IGP Areas and 4-byte AS numbers.
Apart from this, mechanisms defined in this document do not imply any Apart from this, mechanisms defined in this document do not imply any
requirements on other protocols in addition to those already listed requirements on other protocols in addition to those already listed
in [RFC5440]. in [RFC5440].
7.6. Impact On Network Operations 7.6. Impact On Network Operations
Mechanisms defined in this document do not have any impact on network Mechanisms defined in this document do not have any impact on network
operations in addition to those already listed in [RFC5440]. operations in addition to those already listed in [RFC5440].
skipping to change at page 28, line 23 skipping to change at page 28, line 23
Inter-Domain Multiprotocol Label Switching Traffic Inter-Domain Multiprotocol Label Switching Traffic
Engineering", RFC 4726, November 2006. Engineering", RFC 4726, November 2006.
[RFC4873] Berger, L., Bryskin, I., Papadimitriou, D., and A. Farrel, [RFC4873] Berger, L., Bryskin, I., Papadimitriou, D., and A. Farrel,
"GMPLS Segment Recovery", RFC 4873, May 2007. "GMPLS Segment Recovery", RFC 4873, May 2007.
[RFC4874] Lee, CY., Farrel, A., and S. De Cnodder, "Exclude Routes - [RFC4874] Lee, CY., Farrel, A., and S. De Cnodder, "Exclude Routes -
Extension to Resource ReserVation Protocol-Traffic Extension to Resource ReserVation Protocol-Traffic
Engineering (RSVP-TE)", RFC 4874, April 2007. Engineering (RSVP-TE)", RFC 4874, April 2007.
[RFC4893] Vohra, Q. and E. Chen, "BGP Support for Four-octet AS
Number Space", RFC 4893, May 2007.
[RFC5152] Vasseur, JP., Ayyangar, A., and R. Zhang, "A Per-Domain [RFC5152] Vasseur, JP., Ayyangar, A., and R. Zhang, "A Per-Domain
Path Computation Method for Establishing Inter-Domain Path Computation Method for Establishing Inter-Domain
Traffic Engineering (TE) Label Switched Paths (LSPs)", RFC Traffic Engineering (TE) Label Switched Paths (LSPs)", RFC
5152, February 2008. 5152, February 2008.
[RFC5520] Bradford, R., Vasseur, JP., and A. Farrel, "Preserving [RFC5520] Bradford, R., Vasseur, JP., and A. Farrel, "Preserving
Topology Confidentiality in Inter-Domain Path Computation Topology Confidentiality in Inter-Domain Path Computation
Using a Path-Key-Based Mechanism", RFC 5520, April 2009. Using a Path-Key-Based Mechanism", RFC 5520, April 2009.
[RFC5886] Vasseur, JP., Le Roux, JL., and Y. Ikejiri, "A Set of [RFC5886] Vasseur, JP., Le Roux, JL., and Y. Ikejiri, "A Set of
Monitoring Tools for Path Computation Element (PCE)-Based Monitoring Tools for Path Computation Element (PCE)-Based
Architecture", RFC 5886, June 2010. Architecture", RFC 5886, June 2010.
[RFC6793] Vohra, Q. and E. Chen, "BGP Support for Four-Octet
Autonomous System (AS) Number Space", RFC 6793, December
2012.
[RFC7334] Zhao, Q., Dhody, D., King, D., Ali, Z., and R. Casellas, [RFC7334] Zhao, Q., Dhody, D., King, D., Ali, Z., and R. Casellas,
"PCE-Based Computation Procedure to Compute Shortest "PCE-Based Computation Procedure to Compute Shortest
Constrained Point-to-Multipoint (P2MP) Inter-Domain Constrained Point-to-Multipoint (P2MP) Inter-Domain
Traffic Engineering Label Switched Paths", RFC 7334, Traffic Engineering Label Switched Paths", RFC 7334,
August 2014. August 2014.
[PCEP-MIB] [RFC7420] Koushik, A., Stephan, E., Zhao, Q., King, D., and J.
Koushik, A., Emile, S., Zhao, Q., King, D., and J. Hardwick, "Path Computation Element Communication Protocol
Hardwick, "PCE communication protocol(PCEP) Management (PCEP)", RFC 7420, December 2014.
Information Base. (draft-ietf-pce-pcep-mib)", September
2014.
[PCE-P2MP-PER-DEST] [PCE-P2MP-PER-DEST]
Dhody, D., Palle, U., and V. Kondreddy, "Supporting Dhody, D., Palle, U., and V. Kondreddy, "Supporting
explicit inclusion or exclusion of abstract nodes for a explicit inclusion or exclusion of abstract nodes for a
subset of P2MP destinations in Path Computation Element subset of P2MP destinations in Path Computation Element
Communication Protocol (PCEP). (draft-dhody-pce-pcep-p2mp- Communication Protocol (PCEP). (draft-dhody-pce-pcep-p2mp-
per-destination)", September 2014. per-destination)", September 2014.
[DOMAIN-SUBOBJ] [DOMAIN-SUBOBJ]
Dhody, D., Palle, U., Kondreddy, V., and R. Casellas, Dhody, D., Palle, U., Kondreddy, V., and R. Casellas,
"Domain Subobjects for Resource ReserVation Protocol - "Domain Subobjects for Resource ReserVation Protocol -
Traffic Engineering (RSVP-TE). (draft-dhody-ccamp-rsvp-te- Traffic Engineering (RSVP-TE). (draft-ietf-teas-rsvp-te-
domain-subobjects)", July 2014. domain-subobjects-00)", December 2014.
[IRO-SURVEY]
Dhody, D., "Informal Survey into Include Route Object
(IRO) Implementations in Path Computation Element
communication Protocol (PCEP). (draft-dhody-pce-iro-
survey-01)", October 2014.
[IRO-UPDATE] [IRO-UPDATE]
Dhody, D., "Update to Include Route Object (IRO) Dhody, D., "Update to Include Route Object (IRO)
specification in Path Computation Element communication specification in Path Computation Element communication
Protocol (PCEP. (draft-dhody-pce-iro-update-00)", October Protocol (PCEP. (draft-dhody-pce-iro-update-02)", December
2014. 2014.
[ISO10589] [ISO10589]
ISO, "Intermediate system to Intermediate system routing ISO, "Intermediate system to Intermediate system routing
information exchange protocol for use in conjunction with information exchange protocol for use in conjunction with
the Protocol for providing the Connectionless-mode Network the Protocol for providing the Connectionless-mode Network
Service (ISO 8473)", ISO/IEC 10589:2002, 1992. Service (ISO 8473)", ISO/IEC 10589:2002, 1992.
Authors' Addresses Authors' Addresses
Dhruv Dhody Dhruv Dhody
Huawei Technologies Huawei Technologies
Leela Palace Leela Palace
Bangalore, Karnataka 560008 Bangalore, Karnataka 560008
INDIA India
EMail: dhruv.ietf@gmail.com EMail: dhruv.ietf@gmail.com
Udayasree Palle Udayasree Palle
Huawei Technologies Huawei Technologies
Leela Palace Leela Palace
Bangalore, Karnataka 560008 Bangalore, Karnataka 560008
INDIA India
EMail: udayasree.palle@huawei.com EMail: udayasree.palle@huawei.com
Ramon Casellas Ramon Casellas
CTTC CTTC
Av. Carl Friedrich Gauss n7 Av. Carl Friedrich Gauss n7
Castelldefels, Barcelona 08860 Castelldefels, Barcelona 08860
SPAIN Spain
EMail: ramon.casellas@cttc.es EMail: ramon.casellas@cttc.es
 End of changes. 69 change blocks. 
124 lines changed or deleted 118 lines changed or added

This html diff was produced by rfcdiff 1.41. The latest version is available from http://tools.ietf.org/tools/rfcdiff/