PCEP extensions for GMPLS
draft-ietf-pce-gmpls-pcep-extensions-08
The information below is for an old version of the document.
| Document | Type |
This is an older version of an Internet-Draft that was ultimately published as RFC 8779.
Expired & archived
|
|
|---|---|---|---|
| Authors | Cyril Margaria , Oscar Gonzalez de Dios , Fatai Zhang | ||
| Last updated | 2014-01-16 (Latest revision 2013-07-15) | ||
| Replaces | draft-margaria-pce-gmpls-pcep-extensions | ||
| RFC stream | Internet Engineering Task Force (IETF) | ||
| Formats | |||
| Reviews |
GENART Telechat review
(of
-14)
by Elwyn Davies
Almost ready
|
||
| Additional resources | Mailing list discussion | ||
| Stream | WG state | WG Document | |
| Document shepherd | (None) | ||
| IESG | IESG state | Became RFC 8779 (Proposed Standard) | |
| Consensus boilerplate | Unknown | ||
| Telechat date | (None) | ||
| Responsible AD | (None) | ||
| Send notices to | (None) |
draft-ietf-pce-gmpls-pcep-extensions-08
Network Working Group C. Margaria, Ed.
Internet-Draft Coriant GmbH
Intended status: Standards Track O. Gonzalez de Dios, Ed.
Expires: January 16, 2014 Telefonica Investigacion y Desarrollo
F. Zhang, Ed.
Huawei Technologies
July 15, 2013
PCEP extensions for GMPLS
draft-ietf-pce-gmpls-pcep-extensions-08
Abstract
This memo provides extensions for the Path Computation Element
communication Protocol (PCEP) for the support of GMPLS control plane.
Status of This Memo
This Internet-Draft is submitted in full conformance with the
provisions of BCP 78 and BCP 79.
Internet-Drafts are working documents of the Internet Engineering
Task Force (IETF). Note that other groups may also distribute
working documents as Internet-Drafts. The list of current Internet-
Drafts is at http://datatracker.ietf.org/drafts/current/.
Internet-Drafts are draft documents valid for a maximum of six months
and may be updated, replaced, or obsoleted by other documents at any
time. It is inappropriate to use Internet-Drafts as reference
material or to cite them other than as "work in progress."
This Internet-Draft will expire on January 16, 2014.
Copyright Notice
Copyright (c) 2013 IETF Trust and the persons identified as the
document authors. All rights reserved.
This document is subject to BCP 78 and the IETF Trust's Legal
Provisions Relating to IETF Documents
(http://trustee.ietf.org/license-info) in effect on the date of
publication of this document. Please review these documents
carefully, as they describe your rights and restrictions with respect
to this document. Code Components extracted from this document must
include Simplified BSD License text as described in Section 4.e of
the Trust Legal Provisions and are provided without warranty as
described in the Simplified BSD License.
Margaria, et al. Expires January 16, 2014 [Page 1]
Internet-Draft PCEP Ext for GMPLS July 2013
Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2
1.1. Contributing Authors . . . . . . . . . . . . . . . . . . 3
1.2. PCEP requirements for GMPLS . . . . . . . . . . . . . . . 3
1.3. Current GMPLS support and limitation of existing PCEP
objects . . . . . . . . . . . . . . . . . . . . . . . . . 4
1.4. Requirements Language . . . . . . . . . . . . . . . . . . 5
2. PCEP objects and extensions . . . . . . . . . . . . . . . . . 5
2.1. RP object extension . . . . . . . . . . . . . . . . . . . 7
2.2. Traffic parameters encoding, GENERALIZED-BANDWIDTH . . . 8
2.3. Traffic parameters encoding, GENERALIZED-LOAD-BALANCING . 10
2.4. END-POINTS Object extensions . . . . . . . . . . . . . . 12
2.4.1. Generalized Endpoint Object Type . . . . . . . . . . 13
2.4.2. END-POINTS TLVs extensions . . . . . . . . . . . . . 16
2.5. IRO extension . . . . . . . . . . . . . . . . . . . . . . 19
2.6. XRO extension . . . . . . . . . . . . . . . . . . . . . . 20
2.7. LSPA extensions . . . . . . . . . . . . . . . . . . . . . 21
2.8. NO-PATH Object Extension . . . . . . . . . . . . . . . . 22
2.8.1. Extensions to NO-PATH-VECTOR TLV . . . . . . . . . . 22
3. Additional Error Type and Error Values Defined . . . . . . . 23
4. Manageability Considerations . . . . . . . . . . . . . . . . 24
4.1. Control of Function through Configuration and Policy . . 24
4.2. Information and Data Models . . . . . . . . . . . . . . . 25
4.3. Liveness Detection and Monitoring . . . . . . . . . . . . 25
4.4. Verifying Correct Operation . . . . . . . . . . . . . . . 25
4.5. Requirements on Other Protocols and Functional Components 25
4.6. Impact on Network Operation . . . . . . . . . . . . . . . 25
5. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 26
5.1. PCEP Objects . . . . . . . . . . . . . . . . . . . . . . 26
5.2. END-POINTS object, Object Type Generalized Endpoint . . . 26
5.3. New PCEP TLVs . . . . . . . . . . . . . . . . . . . . . . 27
5.4. RP Object Flag Field . . . . . . . . . . . . . . . . . . 28
5.5. New PCEP Error Codes . . . . . . . . . . . . . . . . . . 28
5.6. New NO-PATH-VECTOR TLV Fields . . . . . . . . . . . . . 29
5.7. New Subobject for the Include Route Object . . . . . . . 30
5.8. New Subobject for the Exclude Route Object . . . . . . . 30
6. Security Considerations . . . . . . . . . . . . . . . . . . . 30
7. Contributing Authors . . . . . . . . . . . . . . . . . . . . 30
8. Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . 31
9. References . . . . . . . . . . . . . . . . . . . . . . . . . 32
9.1. Normative References . . . . . . . . . . . . . . . . . . 32
9.2. Informative References . . . . . . . . . . . . . . . . . 33
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 34
1. Introduction
Margaria, et al. Expires January 16, 2014 [Page 2]
Internet-Draft PCEP Ext for GMPLS July 2013
Although [RFC4655] defines the PCE architecture and framework for
both MPLS and GMPLS networks, current PCEP RFCs [RFC5440], [RFC5521],
[RFC5541], [RFC5520] are focused on MPLS networks, and do not cover
the wide range of GMPLS networks. This document complements these
RFCs by addressing the extensions required for GMPLS applications and
routing requests, for example for OTN and WSON networks.
The functional requirements to be considered by the PCEP extensions
to support those application are described in
[I-D.ietf-pce-gmpls-aps-req] and
[I-D.ietf-pce-wson-routing-wavelength].
1.1. Contributing Authors
Elie Sfeir, Franz Rambach (Nokia Siemens Networks) Francisco Javier
Jimenez Chico (Telefonica Investigacion y Desarrollo) Suresh BR,
Young Lee, SenthilKumar S, Jun Sun (Huawei Technologies), Ramon
Casellas (CTTC)
1.2. PCEP requirements for GMPLS
The document [I-D.ietf-pce-gmpls-aps-req] describes the set of PCEP
requirements to support GMPLS TE-LSPs. When a PCC requests a PCE to
perform a path computation (by means of a PCReq message), the PCC
should be able to indicate the following additional information:
o Which data flow is switched by the LSP: a combination of Switching
Type (for instance L2SC or TDM), Switching Encoding (e.g.,
Ethernet, SONET/SDH) and sometimes the Signal Type (e.g. in case
of TDM/LSC switching capability)
o Data flow specific traffic parameters, which are technology
specific. For instance, in SDH/SONET and G.709 OTN networks the
Concatenation Type and the Concatenation Number have an influence
on the switched data and on which link it can be supported
o Support for asymmetric bandwidth requests.
o Support for unnumbered interface identifiers, as defined in
[RFC3477]
o Label information and technology specific label(s) such as
wavelength labels as defined in [RFC6205]. A PCC should also be
able to specify a Label restriction similar to the one supported
by RSVP.
Margaria, et al. Expires January 16, 2014 [Page 3]
Internet-Draft PCEP Ext for GMPLS July 2013
o Ability to indicate the requested granularity for the path ERO:
node, link or label. This is to allow the use of the explicit
label control feature of RSVP-TE.
We describe in this document a set of PCEP protocol extensions,
including new objects, TLVs, encodings, error codes and procedures,
in order to fulfill the aforementioned requirements.
1.3. Current GMPLS support and limitation of existing PCEP objects
PCEP as of [RFC5440], [RFC5521] and [I-D.ietf-pce-inter-layer-ext],
supports the following objects, included in requests and responses
related to the described requirements.
From [RFC5440]:
o ENDPOINTS: only numbered endpoints are considered. The context
specifies whether they are node identifiers or numbered
interfaces.
o BANDWIDTH: the data rate is encoded in the bandwidth object (as
IEEE 32 bit float). [RFC5440] does not include the ability to
convey a (Intserv) TSPEC object.
o ERO : Unnumbered endpoints are supported.
o LSPA: LSP attributes (setup and holding priorities)
From [RFC5521] :
o XRO object :
* This object allows excluding (strict or not) resources, and
includes the requested diversity (node, link or SRLG).
* When the F bit is set, the request indicates that the existing
route has failed and the resources present in the RRO can be
reused.
From [I-D.ietf-pce-inter-layer-ext]:
o INTER-LAYER : indicates whether inter-layer computation is allowed
o SWITCH-LAYER : indicates which layer(s) should be considered, can
be used to represent the RSVP-TE generalized label request
Margaria, et al. Expires January 16, 2014 [Page 4]
Internet-Draft PCEP Ext for GMPLS July 2013
o REQ-ADAP-CAP : indicates the adaptation capabilities requested,
can also be used for the endpoints in case of mono-layer
computation
The shortcomings of the existing PCEP object are:
The BANDWIDTH and LOAD-BALANCING objects do not describe the
details of the traffic request (for example NVC, multiplier) in
the context of GMPLS networks, for instance TDM or OTN networks.
The END-POINTS object does not allow specifying an unnumbered
interface, nor potential label restrictions on the interface.
Those parameters are of interest in case of switching constraints.
The IRO/XRO objects do not allow the inclusion/exclusion of labels
Current attributes do not allow expressing the requested link
protection level and/or the end-to-end protection attributes.
The covered PCEP extensions are:
New objects are introduced (GENERALIZED-BANDWIDTH and GENERALIZED-
LOAD-BALANCING) for flexible bandwidth encoding,
A new object type is introduced for the END-POINTS object
(GENERALIZED-ENDPOINT),
A new TLV is added to the LSPA object.
A new TLV type for label is allowed in IRO and XRO objects.
In order to indicate the used routing granularity in the response,
a new flag in the RP object is added.
1.4. Requirements Language
The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
"SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this
document are to be interpreted as described in RFC 2119 [RFC2119].
2. PCEP objects and extensions
This section describes the required PCEP objects and extensions. The
PCReq and PCRep messages are defined in [RFC5440]. The format of the
PCEP request and response with the proposed extensions (GENERALIZED-
BANDWIDTH, GENERALIZED-LOAD-BALANCING, SUGGESTED-LABEL-SET and LABEL-
SET) is as follows:
Margaria, et al. Expires January 16, 2014 [Page 5]
Internet-Draft PCEP Ext for GMPLS July 2013
<request>::= <RP>
<segment-computation>|<path-key-expansion>
<segment-computation> ::=
<END-POINTS>
[<LSPA>]
[<BANDWIDTH>][<GENERALIZED-BANDWIDTH>...]
[<metric-list>]
[<OF>]
[<RRO> [<BANDWIDTH>][<GENERALIZED-BANDWIDTH>...]]
[<IRO>]
[<LOAD-BALANCING>]
[<GENERALIZED-LOAD-BALANCING>...]
[<XRO>]
<path-key-expansion> ::= <PATH-KEY>
<response>::=<RP>
[<NO-PATH>]
[<attribute-list>]
[<path-list>]
<path-list>::=<path>[<path-list>]
<path>::= <ERO><attribute-list>
<metric-list>::=<METRIC>[<metric-list>]
Where:
<attribute-list>::=[<LSPA>]
[<BANDWIDTH>]
[<GENERALIZED-BANDWIDTH>...]
[<GENERALIZED-LOAD-BALANCING>...]
[<metric-list>]
[<IRO>]
For point-to-multipoint(P2MP) computations, the grammar is:
<segment-computation> ::=
<end-point-rro-pair-list>
[<OF>]
[<LSPA>]
[<BANDWIDTH>]
[<GENERALIZED-BANDWIDTH>...]
[<metric-list>]
[<IRO>]
Margaria, et al. Expires January 16, 2014 [Page 6]
Internet-Draft PCEP Ext for GMPLS July 2013
[<LOAD-BALANCING>]
[<GENERALIZED-LOAD-BALANCING>...]
[<XRO>]
<end-point-rro-pair-list>::=
<END-POINTS>[<RRO-List>][<BANDWIDTH>]
[<GENERALIZED-BANDWIDTH>...]
[<end-point-rro-pair-list>]
<RRO-List>::=<RRO>[<BANDWIDTH>]
[<GENERALIZED-BANDWIDTH>...][<RRO-List>]
2.1. RP object extension
Explicit label control (ELC) is a procedure supported by RSVP-TE,
where the outgoing label(s) is(are) encoded in the ERO. In
consequence, the PCE may be able to provide such label(s) directly in
the path ERO. The PCC, depending on policies or switching layer, may
be required to use explicit label control or expect explicit link,
thus it need to indicate in the PCReq which granularity it is
expecting in the ERO. This correspond to requirement 12 of
[I-D.ietf-pce-gmpls-aps-req] The possible granularities can be node,
link or label. The granularities are inter-dependent, in the sense
that link granularity implies the presence of node information in the
ERO; similarly, a label granularity implies that the ERO contains
node, link and label information.
A new 2-bit routing granularity (RG) flag is defined in the RP
object. The values are defined as follows
0 : node
1 : link
2 : label
3 : reserved
Table 1
The flag in the RP object indicates the requested route granularity.
The PCE MAY try to follow this granularity and MAY return a NO-PATH
if the requested granularity cannot be provided. The PCE MAY return
finer granularity on the route based on its policy. The PCC can
decide if the ERO is acceptable based on its content.
If a PCE honored the the requested routing granularity for a request,
it SHOULD indicate the selected routing granularity in the RP object
included in the response . The RG flag is backward-compatible with
Margaria, et al. Expires January 16, 2014 [Page 7]
Internet-Draft PCEP Ext for GMPLS July 2013
[RFC5440]: the value sent by an implementation (PCC or PCE) not
supporting it will indicate a node granularity.
2.2. Traffic parameters encoding, GENERALIZED-BANDWIDTH
The PCEP BANDWIDTH object does not describe the details of the signal
(for example NVC, multiplier), hence the bandwidth information should
be extended to use the RSVP Tspec object encoding. The PCEP
BANDWIDTH object defines two types: 1 and 2. C-Type 2 is
representing the existing bandwidth in case of re-optimization.
The following possibilities cannot be represented in the BANDWIDTH
object:
o Asymmetric bandwidth (different bandwidth in forward and reverse
direction), as described in [RFC6387]
o GMPLS (SDH/SONET, G.709, ATM, MEF etc) parameters are not
supported.
This correspond to requirement 3,4,5 and 11 of
[I-D.ietf-pce-gmpls-aps-req].
According to [RFC5440] the BANDWIDTH object has no TLV and has a
fixed size of 4 bytes. This definition does not allow extending it
with the required information. To express this information, a new
object named GENERALIZED-BANDWIDTH with Object Type 1, having the
following format is defined. The definitions below apply for Object
Type 1. The payload of the GENERALIZED-BANDWIDTH is as follows:
0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Traffic Spec Length | TSpec Type | Reserved |R|O|
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| |
~ Traffic Spec ~
| |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| |
~ Optional TLVs ~
| |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
The GENERALIZED-BANDWIDTH has a variable length. The Traffic spec
length field indicates the length of the Traffic spec field. The
bits R and O have the following meaning:
Margaria, et al. Expires January 16, 2014 [Page 8]
Internet-Draft PCEP Ext for GMPLS July 2013
O bit : when set the value refers to the previous bandwidth in
case of re-optimization
R bit : when set the value refers to the bandwidth of the reverse
direction
The TSpec Type field determines which type of bandwidth is
represented by the object.
The TSpec Type types correspond to the RSVPT-TE SENDER_TSPEC (Object
Class 12) C-Types
The encoding of the field Traffic Spec is the same as in RSVP-TE, it
can be found in the following references.
Object Type Name Reference
2 Intserv [RFC2210]
4 SONET/SDH [RFC4606]
5 G.709 [RFC4328]
6 Ethernet [RFC6003]
Traffic Spec field encoding
Table 2
The GENERALIZED-BANDWIDTH MAY appear more than once in a request
message. If more than one GENERALIZED-BANDWIDTH objects have the
same Tspec type, Reserved, R and O values, only the first one is
processed, the other objects are ignored.
A PCE MAY ignore GENERALIZED-BANDWIDTH objects, a PCC that requires a
GENERALIZED-BANDWIDTH to be used can set the P (Processing) bit in
the object header.
When a PCC needs to request a bi-directional path with asymmetric
bandwidth, it SHOULD specify the different bandwidth in the forward
and reverse directions through two separate GENERALIZED-BANDWIDTH
objects. If the PCC set the P bit on both objects the PCE MUST
compute a path that satisfies the asymmetric bandwidth constraint .
If the P bit on the reverse or the forward GENERALIZED-BANDWIDTH
object is not set the PCE MAY ignore this constraint.
A PCE MAY include the GENERALIZED-BANDWIDTH objects in the response
to indicate the GENERALIZED-BANDWIDTH of the path
Margaria, et al. Expires January 16, 2014 [Page 9]
Internet-Draft PCEP Ext for GMPLS July 2013
Optional TLVs may be included within the object body to specify more
specific bandwidth requirements. No TLVs for the GENERALIZED-
BANDWIDTH are defined by this document.
2.3. Traffic parameters encoding, GENERALIZED-LOAD-BALANCING
The LOAD-BALANCING object [RFC5440] is used to request a set of
maximum Max-LSP TE-LSP having in total the bandwidth specified in
BANDWIDTH, each TE-LSP having a minimum of bandwidth. The LOAD-
BALANCING follows the bandwidth encoding of the BANDWIDTH object, and
thus it does not describe enough details for the traffic
specification expected by GMPLS. A PCC should be allowed to request
a set of TE-LSP also in case of GMPLS traffic specification.
According to [RFC5440] the LOAD-BALANCING object has no optional
TLVs and has a fixed size of 8 bytes. This definition does not allow
extending it with the required information. To express this
information, a new Object named GENERALIZED-LOAD-BALANCING is
defined.
The GENERALIZED-LOAD-BALANCING object, as the LOAD-BALANCING object,
allows the PCC to request a set of TE-LSP having in total the
GENERALIZED-BANDWIDTH traffic specification with potentially Max-Lsp,
each TE-LSP having a minimum of Min Traffic spec. The GENERALIZED-
LOAD-BALANCING is optional.
GENERALIZED-LOAD-BALANCING Object-Class is to be assigned by IANA.
GENERALIZED-LOAD-BALANCING Object Type 1 is defined below. The TSpec
Type field determines which type of minimum bandwidth is represented
by the object.
The GENERALIZED-LOAD-BALANCING has a variable length.
The format of the GENERALIZED-LOAD-BALANCING object body is as
follows:
0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Traffic spec length | TSpec Type | Flags |R|
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Max-LSP | Reserved |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Min Traffic Spec |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| |
~ Optional TLVs ~
| |
Margaria, et al. Expires January 16, 2014 [Page 10]
Internet-Draft PCEP Ext for GMPLS July 2013
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Traffic spec length (16 bits): the total length of the min traffic
specification. It should be noted that the RSVP traffic
specification may also include TLV different than the PCEP TLVs.
TSpec Type (8 bits) : the traffic specification type, it correspond
to the RSVPT-TE SENDER_TSPEC (Object Class 12) C-Types
Flags (8 bits): The undefined Flags field MUST be set to zero on
transmission and MUST be ignored on receipt. The following flag is
defined:
R Flag : (1 bit) set when the value refer to the bandwidth of the
reverse direction
Max-LSP (8 bits): maximum number of TE LSPs in the set.
Min-Traffic spec (variable): Specifies the minimum traffic spec of
each element of the set of TE LSPs.
The encoding of the field Min Traffic Spec is the same as in RSVP-TE,
it can be found in the following references.
Object Type Name Reference
2 Intserv [RFC2210]
4 SONET/SDH [RFC4606]
5 G.709 [RFC4328]
6 Ethernet [RFC6003]
Traffic Spec field encoding
Table 3
The GENERALIZED-LOAD-BALANCING MAY appear more than once in a PCEP
request. If more than one GENERALIZED-LOAD-BALANCING have the same
TSpec Type, and R Flag, only the first one is processed, the others
are ignored.
A PCE MAY ignore GENERALIZED-LOAD-BALANCING objects. A PCC that
requires a GENERALIZED-LOAD-BALANCING to be used can set the P
(Processing) bit in the object header.
When a PCC needs to request a bi-directional path with asymmetric
bandwidth while specifying load balancing constraints, it SHOULD
specify the different bandwidth in forward and reverse directions
Margaria, et al. Expires January 16, 2014 [Page 11]
Internet-Draft PCEP Ext for GMPLS July 2013
through two separate GENERALIZED-LOAD-BALANCING objects with
different R Flag. If the PCC set the P bit on both object the PCE
MUST compute a path that satisfies the asymmetric bandwidth
constraint . If the P bit is not set the reverse or forward
GENERALIZED-LOAD-BALANCING object the PCE MAY ignore this constraint.
Optional TLVs may be included within the object body to specify more
specific bandwidth requirements. No TLVs for the GENERALIZED-LOAD-
BALANCING are defined by this document.
The GENERALIZED-LOAD-BALANCING object has the same semantic as the
LOAD-BALANCING object; If a PCC requests the computation of a set of
TE LSPs so that the total of their generalized bandwidth is X, the
maximum number of TE LSPs is N, and each TE LSP must at least have a
bandwidth of B, it inserts a GENERALIZED-BANDWIDTH object specifying
X as the required bandwidth and a GENERALIZED-LOAD-BALANCING object
with the Max-LSP and Min-traffic spec fields set to N and B,
respectively.
For example a request for one co-signaled n x VC-4 TE-LSP will not
use the GENERALIZED-LOAD-BALANCING. In case the V4 components can
use different paths, the GENERALIZED-BANDWIDTH will contain a traffic
specification indicating the complete n x VC4 traffic specification
and the GENERALIZED-LOAD-BALANCING the minimum co-signaled VC4. For
a SDH network, a request to have a TE-LSP group with 10 VC4
container, each path using at minimum 2VC4 container, can be
represented with a GENERALIZED-BANDWIDTH object with OT=4, the
content of the Traffic specification is ST=6,RCC=0,NCC=0,NVC=10,MT=1.
The GENERALIZED-LOAD-BALANCING, OT=4,R=0,Max-LSP=5, min Traffic spec
is (ST=6,RCC=0,NCC=0,NVC=2,MT=1). The PCE can respond with a
response with maximum 5 path, each of them having a GENERALIZED-
BANDWIDTH OT=4,R=0, and traffic spec matching the minimum traffic
spec from the GENERALIZED-LOAD-BALANCING object of the corresponding
request.
2.4. END-POINTS Object extensions
The END-POINTS object is used in a PCEP request message to specify
the source and the destination of the path for which a path
computation is requested. From [RFC5440]the source IP address and
the destination IP address are used to identify those. A new Object
Type is defined to address the following possibilities:
o Different source and destination endpoint types.
o Label restrictions on the endpoint.
Margaria, et al. Expires January 16, 2014 [Page 12]
Internet-Draft PCEP Ext for GMPLS July 2013
o Specification of unnumbered endpoints type as seen in GMPLS
networks.
The Object encoding is described in the following sections.
In path computation within a GMPLS context the endpoints can:
o Be unnumbered as described in [RFC3477].
o Have label(s) associated to them, specifying a set of constraints
in the allocation of labels.
o May have different switching capabilities
The IPv4 and IPv6 endpoints are used to represent the source and
destination IP addresses. The scope of the IP address (Node or
numbered Link) is not explicitly stated. It is also possible to
request a Path between a numbered link and an unnumbered link, or a
P2MP path between different type of endpoints.
This new C-Type also supports the specification of constraints on the
endpoint label to be use. The PCE might know the interface
restrictions but this is not a requirement. This corresponds to
requirements 6 and 10 of [I-D.ietf-pce-gmpls-aps-req].
2.4.1. Generalized Endpoint Object Type
The Generalized Endpoint object type format consists of a body and a
list of TLVs scoped to this object type object. The TLVs give the
details of the endpoints and are described in Section 2.4.2. For
each endpoint type, a different grammar is defined. The TLVs defined
to describe an endpoint are:
1. IPv4 address endpoint.
2. IPv6 address endpoint.
3. Unnumbered endpoint.
4. Label set restriction.
5. Suggested label set restriction.
The Label Set and Suggested label set TLVs are used to restrict the
label allocation in the PCE. Those TLVs express the set of
restrictions provided by signaling. Label restriction support can be
an explicit value (Label set describing one label), mandatory range
restrictions (Label set), optional range restriction (suggested label
Margaria, et al. Expires January 16, 2014 [Page 13]
Internet-Draft PCEP Ext for GMPLS July 2013
set) and single suggested value is using the suggested label set.
Endpoints label restriction may not be part of the RRO or IRO, they
may be included when following [RFC4003] in signaling for egress
endpoint, but ingress endpoint properties may be local to the PCC and
not signaled. To support this case the label set allows to indicate
which label are used in case of reoptimization. The label range
restrictions are valid in GMPLS networks, either by PCC policy or
depending on the switching technology used, for instance on given
Ethernet or ODU equipment having limited hardware capabilities
restricting the label range. Label set restriction also applies to
WSON networks where the optical sender and receivers are limited in
their frequency tunability ranges, restricting then in GMPLS the
possible label ranges on the interface. The END-POINTS Object with
Generalized Endpoint object type is encoded as follow:
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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Reserved | endpoint type |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| |
~ TLVs ~
| |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Reserved bits should be set to 0 when a message is sent and ignored
when the message is received
the endpoint type is defined as follow:
Value Type Meaning
0 Point-to-Point
1 Point-to-Multipoint New leaves to add
2 Old leaves to remove
3 Old leaves whose path can be
modified/reoptimized
4 Old leaves whose path must be
left unchanged
5-244 Reserved
245-255 Experimental range
Table 4
The endpoint type is used to cover both point-to-point and different
point-to-multipoint endpoints. Endpoint type 0 MAY be accepted by
Margaria, et al. Expires January 16, 2014 [Page 14]
Internet-Draft PCEP Ext for GMPLS July 2013
the PCE, other endpoint type MAY be supported if the PCE
implementation supports P2MP path calculation. A PCE not supporting
a given endpoint type MUST respond with a PCErr with error code "Path
computation failure", error type "Unsupported endpoint type in END-
POINTS Generalized Endpoint object type". The TLVs present in the
request object body MUST follow the following grammar:
<generalized-endpoint-tlvs>::=
<p2p-endpoints> | <p2mp-endpoints>
<p2p-endpoints> ::=
<source-endpoint>
<destination-endpoint>
<source-endpoint> ::=
<endpoint>
[<endpoint-restriction-list>]
<destination-endpoint> ::=
<endpoint>
[<endpoint-restriction-list>]
<p2mp-endpoints> ::=
<endpoint> [<endpoint-restriction-list>]
[<endpoint> [<endpoint-restriction-list>]]...
For endpoint type Point-to-Multipoint several endpoint objects may be
present in the message and represent a leave, exact meaning depend on
the endpoint type defined of the object.
An endpoint is defined as follows:
<endpoint>::=<IPV4-ADDRESS>|<IPV6-ADDRESS>|<UNNUMBERED-ENDPOINT>
<endpoint-restriction-list> ::= <endpoint-restriction>
[<endpoint-restriction-list>]
<endpoint-restriction> ::=
<LABEL-REQUEST><label-restriction-list>
<label-restriction-list> ::= <label-restriction>
[<label-restriction-list>]
<label-restriction> ::= <LABEL-SET>|
<SUGGESTED-LABEL-SET>
Margaria, et al. Expires January 16, 2014 [Page 15]
Internet-Draft PCEP Ext for GMPLS July 2013
The different TLVs are described in the following sections. A PCE
MAY support IPV4-ADDRESS,IPV6-ADDRESS or UNNUMBERED-ENDPOINT TLV. A
PCE not supporting one of those TLV in a PCReq MUST respond with a
PCRep with NO-PATH with the bit "Unknown destination" or "Unknown
source" in the NO-PATH-VECTOR TLV, the response SHOULD include the
ENDPOINT object in the response with only the TLV it did not
understood.
A PCE MAY support LABEL-REQUEST, LABEL-SET or SUGGESTED-LABEL-SET
TLV. If a PCE finds a non-supported TLV in the END-POINTS the PCE
MUST respond with a PCErr message with error type="Path computation
failure" error value="Unsupported TLV present in END-POINTS
Generalized Endpoint object type" and the message SHOULD include the
ENDPOINT object in the response with only the endpoint and endpoint
restriction TLV it did not understand. A PCE not supporting those
TLVs but not being able to fulfill the label restriction MUST respond
with a response with NO-PATH with the bit "No endpoint label
resource" or "No endpoint label resource in range" in the NO-PATH-
VECTOR TLV, the response SHOULD include the ENDPOINT object in the
response with only the TLV where it could not met the constraint.
2.4.2. END-POINTS TLVs extensions
All endpoint TLVs have the standard PCEP TLV header as defined in
[RFC5440] section 7.1. In this object type the order of the TLVs
MUST be followed according to the object type definition.
2.4.2.1. IPV4-ADDRESS
This TLV represent a numbered endpoint using IPv4 numbering, the
format of the IPv4-ADDRESS TLV value (TLV-Type=TBA) is as follows:
0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| IPv4 address |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
This TLV MAY be ignored, in which case a PCRep with NO-PATH should be
responded, as described in Section 2.4.1.
2.4.2.2. IPV6-ADDRESS TLV
This TLV represent a numbered endpoint using IPV6 numbering, the
format of the IPv6-ADDRESS TLV value (TLV-Type=TBA) is as follows:
Margaria, et al. Expires January 16, 2014 [Page 16]
Internet-Draft PCEP Ext for GMPLS July 2013
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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| IPv6 address (16 bytes) |
| |
| |
| |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
This TLV MAY be ignored, in which case a PCRep with NO-PATH should be
responded, as described in Section 2.4.1.
2.4.2.3. UNNUMBERED-ENDPOINT TLV
This TLV represent an unnumbered interface. This TLV has the same
semantic as in [RFC3477] The TLV value is encoded as follow (TLV-
Type=TBA)
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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| LSR's Router ID |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Interface ID (32 bits) |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
This TLV MAY be ignored, in which case a PCRep with NO-PATH should be
responded, as described in Section 2.4.1.
2.4.2.4. LABEL-REQUEST TLV
The LABEL-REQUEST TLV indicates the switching capability and encoding
type of the following label restriction list for the endpoint. Its
format is the same as described in [RFC3471] Section 3.1 Generalized
label request. The LABEL-REQUEST TLV use TLV-Type=TBA. The fields
are encoded as in the RSVP-TE. The Encoding Type indicates the
encoding type, e.g., SONET/SDH/GigE etc., that will be used with the
data associated. The Switching type indicates the type of switching
that is being requested on the endpoint. G-PID identifies the
payload. This TLV and the following one are introduced to satisfy
requirement 13 for the endpoint. It is not directly related to the
TE-LSP label request, which is expressed by the SWITCH-LAYER object.
On the path calculation request only the Tspec and switch layer need
to be coherent, the endpoint labels could be different (supporting a
different Tspec). Hence the label restrictions include a Generalized
Margaria, et al. Expires January 16, 2014 [Page 17]
Internet-Draft PCEP Ext for GMPLS July 2013
label request in order to interpret the labels. This TLV MAY be
ignored, in which case a PCRep with NO-PATH should be responded, as
described in Section 2.4.1.
2.4.2.5. Labels TLV
Label or label range restrictions may be specified for the TE-LSP
endpoints. Those are encoded using the LABEL-SET TLV. The label
value need to be interpreted with a description on the Encoding and
switching type. The REQ-ADAP-CAP object from
[I-D.ietf-pce-inter-layer-ext] can be used in case of mono-layer
request, however in case of multilayer it is possible to have in the
future more than one object, so it is better to have a dedicated TLV
for the label and label request (the scope is then more clear).
Those TLV MAY be ignored, in which case a response with NO-PATH
should be responded, as described in Section 2.4.1. TLVs are encoded
as follow (following [RFC5440]) :
o LABEL-SET TLV, Type=TBA. The TLV Length is variable, Encoding
follows [RFC3471] Section 3.5 "Label set" with the addition of a U
bit and O Bit. The U bit is set for upstream direction in case of
bidirectional LSP and the O bit is used to represent an old label.
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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Action | Reserved |O|U| Label Type |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Subchannel 1 |
| ... |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
: : :
: : :
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Subchannel N |
| ... |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
o SUGGESTED-LABEL-SET TLV Set, Type=TBA. The TLV length is variable
and its encoding is as LABEL-SET TLV. The 0 bit SHOULD be set to
0.
A LABEL-SET TLV represents a set of possible labels that can be used
on an interface. The label allocated on the first link SHOULD be
within the label set range. The action parameter in the Label set
indicates the type of list provided. Those parameters are described
Margaria, et al. Expires January 16, 2014 [Page 18]
Internet-Draft PCEP Ext for GMPLS July 2013
by [RFC3471] section 3.5.1 A SUGGESTED-LABEL-SET TLV has the same
encoding as the LABEL-SET TLV, it indicates to the PCE a set of
preferred (ordered) set of labels to be used. The PCE MAY use those
labels for label allocation.
The U and 0 bits have the following meaning:
U: Upstream direction: set when the label or label set is in the
reverse direction
O: Old Label: set when the TLV represent the old label in case of re-
optimization. This Bit SHOULD be set to 0 in a SUGGESTED-LABEL-SET
TLV Set. This Label MAY be reused. The R bit of the RP object MUST
be set. When this bit is set the Action field MUST be set to 0
(Inclusive List) and the Label Set MUST contain one subchannel.
Table 5
Several LABEL_SET TLVs MAY be present with the 0 bit cleared. At
most 2 LABEL_SET TLV SHOULD be present with the 0 bit set, at most
one with the U bit set and at most one with the U bit cleared. For a
given U bit value if more than one LABEL_SET TLV with the O bit set
is present, the first TLV SHOULD be processed and the following TLV
with the same U and O bit SHOULD be ignored.
A SUGGESTED-LABEL-SET TLV with the O bit set MUST trigger a PCErr
message with error type="Reception of an invalid object" error
value="Wrong LABEL-SET or SUGGESTED-LABEL-SET TLV present with 0 bit
set".
A LABEL-SET TLV with the O bit set and an Action Field not set to 0
(Inclusive list) or containing more than one subchannel MUST trigger
a PCErr message with error type="Reception of an invalid object"
error value="Wrong LABEL-SET or SUGGESTED-LABEL-SET TLV present with
0 bit set".
If a LABEL-SET TLV is present with O bit set, the R bit of the RP
object MUST be set or a PCErr message with error type="Reception of
an invalid object" error value="LABEL-SET TLV present with 0 bit set
but without R bit set in RP".
2.5. IRO extension
The IRO as defined in [RFC5440] is used to include specific objects
in the path. RSVP allows to include label definition, in order to
fulfill requirement 13 the IRO should support the new subobject type
as defined in [RFC3473]:
Margaria, et al. Expires January 16, 2014 [Page 19]
Internet-Draft PCEP Ext for GMPLS July 2013
Type Sub-object
3 LABEL
The L bit of such sub-object has no meaning within an IRO.
The Label subobject MUST follow a subobject identifying a link ,
currently an IP address subobject (Type 1 or 2) or an interface id
(type 4) subobject. The procedure associated with this subobject is
as follow
If the PCE allocates labels (e.g via explicit label control) the PCE
MUST allocate one label of from within the set of label values for
the given link. If the PCE does not assign labels a response with a
NO-PATH and a NO-PATH-VECTOR-TLV with the bit .'No label resource in
range' set.
2.6. XRO extension
The XRO as defined in [RFC5521] is used to exclude specific objects
in the path. RSVP allows to exclude labels ([RFC6001], in order to
fulfill requirement 13 of [I-D.ietf-pce-gmpls-aps-req] section 4.1,
the XRO should support a new subobject to support label exclusion.
The encoding of the XRO Label subobject follows the encoding of the
Label ERO subobject defined in [RFC3473] and XRO subobject defined in
[RFC5521]. The XRO Label subobject is defined as follows:
XRO Subobject Type 3: Label Subobject.
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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|X| Type=3 | Length |U| Reserved | C-Type |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Label |
| ... |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
X (1 bit)
See [RFC5521].
Type (7 bits)
Margaria, et al. Expires January 16, 2014 [Page 20]
Internet-Draft PCEP Ext for GMPLS July 2013
The Type of the XRO Label subobject is 3.
Length (8 bits)
See [RFC5521],The total length of the subobject in bytes
(including the Type and Length fields). The Length is always
divisible by 4.
U (1 bit)
See [RFC3471].
C-Type (8 bits)
The C-Type of the included Label Object. Copied from the Label
Object (see [RFC3471]).
Label
See [RFC3471].
XRO Label subobjects MUST follow the numbered or unnumbered interface
subobjects to which they refer. Several XRO Labels subobject MAY be
present.
Type Sub-object
3 LABEL
The L bit of such sub-object has no meaning within an XRO.
2.7. LSPA extensions
The LSPA carries the LSP attributes. In the end-to-end protection
context this also includes the protection state information. This
object is introduced to fulfill requirement 7 of
[I-D.ietf-pce-gmpls-aps-req] section 4.1 and requirement 3 of
[I-D.ietf-pce-gmpls-aps-req] section 4.2 and may be used as a policy
input for route and label selection on request. The LSPA object MAY
Margaria, et al. Expires January 16, 2014 [Page 21]
Internet-Draft PCEP Ext for GMPLS July 2013
carry a PROTECTION-ATTRIBUTE TLV defined as : Type TBA: PROTECTION-
ATTRIBUTE
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 |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|S|P|N|O| Reserved | LSP Flags | Reserved | Link Flags|
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|I|R| Reserved | Seg.Flags | Reserved |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
The content is as defined in [RFC4872], [RFC4873].
LSP Flags can be considered for routing policy based on the
protection type. The other attributes are only meaningful for a
stateful PCE.
This TLV is optional and MAY be ignored by the PCE, in which case it
MUST NOT include the TLV in the LSPA, if present, of the response.
When the TLV is used by the PCE, a LSPA object and the PROTECTION-
ATTRIBUTE TLV MUST be included in the response. Fields that were not
considered MUST be set to 0.
2.8. NO-PATH Object Extension
The NO-PATH object is used in PCRep messages in response to an
unsuccessful path computation request (the PCE could not find a path
satisfying the set of constraints). In this scenario, PCE MUST
include a NO-PATH object in the PCRep message. The NO-PATH object
may carries the NO-PATH-VECTOR TLV that specifies more information on
the reasons that led to a negative reply. In case of GMPLS networks
there could be some more additional constraints that led to the
failure like protection mismatch, lack of resources, and so on. Few
new flags have been introduced in the 32-bit flag field of the NO-
PATH-VECTOR TLV and no modifications have been made in the NO-PATH
object.
2.8.1. Extensions to NO-PATH-VECTOR TLV
The modified NO-PATH-VECTOR TLV carrying the additional information
is as follows:
Bit number TBA - Protection Mismatch (1-bit). Specifies the
mismatch of the protection type in the PROTECTION-ATTRIBUTE TLV in
the request.
Margaria, et al. Expires January 16, 2014 [Page 22]
Internet-Draft PCEP Ext for GMPLS July 2013
Bit number TBA - No Resource (1-bit). Specifies that the
resources are not currently sufficient to provide the path.
Bit number TBA - Granularity not supported (1-bit). Specifies
that the PCE is not able to provide a route with the requested
granularity.
Bit number TBA - No endpoint label resource (1-bit). Specifies
that the PCE is not able to provide a route because of the
endpoint label restriction.
Bit number TBA - No endpoint label resource in range (1-bit).
Specifies that the PCE is not able to provide a route because of
the endpoint label set restriction.
Bit number TBA - No label resource in range (1-bit). Specifies
that the PCE is not able to provide a route because of the label
set restriction.
3. Additional Error Type and Error Values Defined
A PCEP-ERROR object is used to report a PCEP error and is
characterized by an Error-Type that specifies the type of error while
Error-value that provides additional information about the error. An
additional error type and few error values are defined to represent
some of the errors related to the newly identified objects related to
GMPLS networks. For each PCEP error, an Error-Type and an Error-
value are defined. Error-Type 1 to 10 are already defined in
[RFC5440]. Additional Error- values are defined for Error-Type 10
and A new Error-Type is introduced (value TBA).
Error-Type Error-value
10 Reception of an
invalid object
value=TBA: Bad Generalized Bandwidth Object
value.
value=TBA: Unsupported LSP Protection Type in
PROTECTION-ATTRIBUTE TLV.
value=TBA: Unsupported LSP Protection Flags in
PROTECTION-ATTRIBUTE TLV.
value=TBA: Unsupported Secondary LSP Protection
Flags in PROTECTION-ATTRIBUTE TLV.
value=TBA: Unsupported Link Protection Type in
PROTECTION-ATTRIBUTE TLV.
value=TBA: Unsupported Link Protection Type in
PROTECTION-ATTRIBUTE TLV.
value=TBA: LABEL-SET TLV present with 0 bit set
Margaria, et al. Expires January 16, 2014 [Page 23]
Internet-Draft PCEP Ext for GMPLS July 2013
but without R bit set in RP.
value=TBA: Wrong LABEL-SET or
SUGGESTED-LABEL-SET TLV present with
0 bit set.
TBA Path computation
failure
value=TBA: Unacceptable request message.
value=TBA: Generalized bandwidth object not
supported.
value=TBA: Label Set constraint could not be
met.
value=TBA: Label constraint could not be
met.
value=TBA: Unsupported endpoint type in
END-POINTS Generalized Endpoint
object type.
value=TBA: Unsupported TLV present in END-
POINTS Generalized Endpoint object
type.
value=TBA: Unsupported granularity in the RP
object flags.
4. Manageability Considerations
This section follows the guidance of [RFC6123].
4.1. Control of Function through Configuration and Policy
This document makes no change to the basic operation of PCEP and so
the requirements described in [RFC5440] Section 8.1. also apply to
this document. In addition to those requirements a PCEP
implementation MAY allow the configuration of the following
parameters:
Accepted RG in the RP object.
Default RG to use (overriding the one present in the PCReq)
Accepted GENERALIZED-BANDWIDTH parameters in request, default
mapping to use when not specified in the request
Accepted GENERALIZED-LOAD-BALANCING parameters in request.
Accepted endpoint type in END-POINTS object type Generalized
Endpoint and allowed TLVs
Margaria, et al. Expires January 16, 2014 [Page 24]
Internet-Draft PCEP Ext for GMPLS July 2013
Accepted range for label restrictions in label restriction in END-
POINTS, or IRO or XRO objects
PROTECTION-ATTRIBUTE TLV acceptance and suppression.
Those parameters configuration are applicable to the different
sessions as described in [RFC5440] Section 8.1 (by default, per PCEP
peer, ..etc).
4.2. Information and Data Models
This document makes no change to the basic operation of PCEP and so
the requirements described in [RFC5440] Section 8.2. also apply to
this document. This document does not introduces new ERO sub object,
ERO information model is already covered in [RFC4802].
4.3. Liveness Detection and Monitoring
This document makes no change to the basic operation of PCEP and so
there are no changes to the requirements for liveness detection and
monitoring set out in [RFC4657] and [RFC5440] Section 8.3.
4.4. Verifying Correct Operation
This document makes no change to the basic operations of PCEP and
considerations described in [RFC5440] Section 8.4. New errors
introduced by this document should be covered by the requirement to
log error events.
4.5. Requirements on Other Protocols and Functional Components
No new Requirements on Other Protocols and Functional Components are
made by this document. This document does not require ERO object
extensions. Any new ERO subobject defined in CCAMP working group can
be adopted without modifying the operations defined in this document.
4.6. Impact on Network Operation
This document makes no change to the basic operations of PCEP and
considerations described in [RFC5440] Section 8.6. In addition to
the limit on the rate of messages sent by a PCEP speaker, a limit MAY
be placed on the size of the PCEP messages.
Margaria, et al. Expires January 16, 2014 [Page 25]
Internet-Draft PCEP Ext for GMPLS July 2013
5. IANA Considerations
IANA assigns values to the PCEP protocol objects and TLVs. IANA is
requested to make some allocations for the newly defined objects and
TLVs introduced in this document. Also, IANA is requested to manage
the space of flags that are newly added in the TLVs.
5.1. PCEP Objects
As described in Section 2.2 and Section 2.3new Objects are defined
IANA is requested to make the following Object-Type allocations from
the "PCEP Objects" sub-registry.
Object Class to be assigned
Name GENERALIZED-BANDWIDTH
Object-Type 1
Reference This document (section Section 2.2)
Object Class to be assigned
Name GENERALIZED-LOAD-BALANCING
Object-Type 1
Reference This document (section Section 2.3)
As described in Section 2.4.1 a new Object type is defined IANA is
requested to make the following Object-Type allocations from the
"PCEP Objects" sub-registry. The values here are suggested for use
by IANA.
Object Class 4
Name END-POINTS
Object-Type 5 : Generalized Endpoint
6-15 : unassigned
Reference This document (section Section 2.2)
5.2. END-POINTS object, Object Type Generalized Endpoint
IANA is requested to create a registry to manage the endpoint type
field of the END-POINTS object, Object Type Generalized Endpoint and
manage the code space.
Margaria, et al. Expires January 16, 2014 [Page 26]
Internet-Draft PCEP Ext for GMPLS July 2013
New endpoint type in the Reserved range may be allocated by an IETF
consensus action. Each endpoint type should be tracked with the
following qualities:
o endpoint type
o Description
o Defining RFC
New endpoint type in the Experimental range are for experimental use;
these will not be registered with IANA and MUST NOT be mentioned by
RFCs.
The following values have been defined by this document.
(Section 2.4.1, Table 4):
Value Type Meaning
0 Point-to-Point
1 Point-to-Multipoint New leaves to add
2 Old leaves to remove
3 Old leaves whose path can be
modified/reoptimized
4 Old leaves whose path must be
left unchanged
5-244 Reserved
245-255 Experimental range
5.3. New PCEP TLVs
IANA manages the PCEP TLV code point registry (see [RFC5440]). This
is maintained as the "PCEP TLV Type Indicators" sub-registry of the
"Path Computation Element Protocol (PCEP) Numbers" registry. This
document defines new PCEP TLVs, to be carried in the END-POINTS
object with Generalized Endpoint object Type. IANA is requested to
do the following allocation. The values here are suggested for use
by IANA.
Value Meaning Reference
7 IPv4 endpoint This document (section Section
2.4.2.1)
8 IPv6 endpoint This document (section Section
2.4.2.2)
9 Unnumbered endpoint This document (section Section
2.4.2.3)
Margaria, et al. Expires January 16, 2014 [Page 27]
Internet-Draft PCEP Ext for GMPLS July 2013
10 Label request This document (section Section
2.4.2.4)
11 Requested GMPLS Label Set This document (section Section
2.4.2.5)
12 Suggested GMPLS Label Set This document (section Section
2.4.2.5)
13 LSP Protection Information This document (section Section
2.7)
5.4. RP Object Flag Field
As described in Section 2.1 new flag are defined in the RP Object
Flag IANA is requested to make the following Object-Type allocations
from the "RP Object Flag Field" sub-registry. The values here are
suggested for use by IANA.
Bit Description Reference
bit 17-16 routing granularity (RG) This document, Section 2.1
5.5. New PCEP Error Codes
As described in Section Section 3, new PCEP Error-Type and Error
Values are defined. IANA is requested to make the following
allocation in the "PCEP-ERROR Object Error Types and Values"
registry. The values here are suggested for use by IANA.
Error name Reference
Type=10 Reception of an invalid object [RFC5440]
Value=2: Bad Generalized Bandwidth Object This Document
value.
Value=3: Unsupported LSP Protection Type in This Document
PROTECTION-ATTRIBUTE TLV.
Value=4: Unsupported LSP Protection Flags This Document
in PROTECTION-ATTRIBUTE TLV.
Value=5: Unsupported Secondary LSP This Document
Protection Flags in PROTECTION-
ATTRIBUTE TLV.
Value=6: Unsupported Link Protection Type This Document
in PROTECTION-ATTRIBUTE TLV.
Value=7: Unsupported Link Protection Type This Document
in PROTECTION-ATTRIBUTE TLV.
Value=8: LABEL-SET TLV present with 0 bit This Document
set but without R bit set in RP.
Value=9: Wrong LABEL-SET or SUGGESTED- This Document
Margaria, et al. Expires January 16, 2014 [Page 28]
Internet-Draft PCEP Ext for GMPLS July 2013
LABEL-SET TLV present with 0 bit
set.
Type=14 Path computation failure This Document
Value=1: Unacceptable request message. This Document
Value=2: Generalized bandwidth object not This Document
supported.
Value=3: Label Set constraint could not be This Document
met.
Value=4: Label constraint could not be met. This Document
Value=5: Unsupported endpoint type in END- This Document
POINTS Generalized Endpoint
object type
Value=6: Unsupported TLV present in END- This Document
POINTS Generalized Endpoint
object type
Value=7: Unsupported granularity in the RP This Document
object flags
5.6. New NO-PATH-VECTOR TLV Fields
As described in Section Section 2.8.1, new NO-PATH-VECTOR TLV Flag
Fields have been defined. IANA is requested to do the following
allocations in the "NO-PATH-VECTOR TLV Flag Field" sub-registry. The
values here are suggested for use by IANA.
Bit number 23 - Protection Mismatch (1-bit). Specifies the
mismatch of the protection type of the PROTECTION-ATTRIBUTE TLV in
the request.
Bit number 22 - No Resource (1-bit). Specifies that the resources
are not currently sufficient to provide the path.
Bit number 21 - Granularity not supported (1-bit). Specifies that
the PCE is not able to provide a route with the requested
granularity.
Bit number 20 - No endpoint label resource (1-bit). Specifies
that the PCE is not able to provide a route because of the
endpoint label restriction.
Bit number 19 - No endpoint label resource in range (1-bit).
Specifies that the PCE is not able to provide a route because of
the endpoint label set restriction.
Bit number 18 - No label resource in range (1-bit). Specifies
that the PCE is not able to provide a route because of the label
set restriction.
Margaria, et al. Expires January 16, 2014 [Page 29]
Internet-Draft PCEP Ext for GMPLS July 2013
5.7. New Subobject for the Include Route Object
The "PCEP Parameters" registry contains a subregistry "PCEP Objects"
with an entry for the Include Route Object (IRO).
IANA is requested to add a further subobject that can be carried in
the IRO as follows:
Subobject type Reference
3 Label suboject [RFC3473]
5.8. New Subobject for the Exclude Route Object
The "PCEP Parameters" registry contains a subregistry "PCEP Objects"
with an entry for the XRO object (Exclude Route Object).
IANA is requested to add a further subobject that can be carried in
the XRO as follows:
Subobject type Reference
3 Label suboject [RFC3473]
6. Security Considerations
None.
7. Contributing Authors
Nokia Siemens Networks:
Elie Sfeir
St Martin Strasse 76
Munich, 81541
Germany
Phone: +49 89 5159 16159
Email: elie.sfeir@nsn.com
Franz Rambach
St Martin Strasse 76
Munich, 81541
Germany
Phone: +49 89 5159 31188
Margaria, et al. Expires January 16, 2014 [Page 30]
Internet-Draft PCEP Ext for GMPLS July 2013
Email: franz.rambach@nsn.com
Francisco Javier Jimenez Chico
Telefonica Investigacion y Desarrollo
C/ Emilio Vargas 6
Madrid, 28043
Spain
Phone: +34 91 3379037
Email: fjjc@tid.es
Huawei Technologies
Suresh BR
Shenzhen
China
Email: sureshbr@huawei.com
Young Lee
1700 Alma Drive, Suite 100
Plano, TX 75075
USA
Phone: (972) 509-5599 (x2240)
Email: ylee@huawei.com
SenthilKumar S
Shenzhen
China
Email: senthilkumars@huawei.com
Jun Sun
Shenzhen
China
Email: johnsun@huawei.com
CTTC - Centre Tecnologic de Telecomunicacions de Catalunya
Ramon Casellas
PMT Ed B4 Av. Carl Friedrich Gauss 7
08860 Castelldefels (Barcelona)
Spain
Phone: (34) 936452916
Email: ramon.casellas@cttc.es
8. Acknowledgments
Margaria, et al. Expires January 16, 2014 [Page 31]
Internet-Draft PCEP Ext for GMPLS July 2013
The research of Ramon Casellas, Francisco Javier Jimenez Chico, Oscar
Gonzalez de Dios, Cyril Margaria, and Franz Rambach leading to these
results has received funding from the European Community's Seventh
Framework Program FP7/2007-2013 under grant agreement no 247674.
The authors would like to thank Lyndon Ong and Giada Lander for their
useful comments to the document.
9. References
9.1. Normative References
[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
Requirement Levels", BCP 14, RFC 2119, March 1997.
[RFC2210] Wroclawski, J., "The Use of RSVP with IETF Integrated
Services", RFC 2210, September 1997.
[RFC3471] Berger, L., "Generalized Multi-Protocol Label Switching
(GMPLS) Signaling Functional Description", RFC 3471,
January 2003.
[RFC3473] Berger, L., "Generalized Multi-Protocol Label Switching
(GMPLS) Signaling Resource ReserVation Protocol-Traffic
Engineering (RSVP-TE) Extensions", RFC 3473, January 2003.
[RFC3477] Kompella, K. and Y. Rekhter, "Signalling Unnumbered Links
in Resource ReSerVation Protocol - Traffic Engineering
(RSVP-TE)", RFC 3477, January 2003.
[RFC4003] Berger, L., "GMPLS Signaling Procedure for Egress
Control", RFC 4003, February 2005.
[RFC4328] Papadimitriou, D., "Generalized Multi-Protocol Label
Switching (GMPLS) Signaling Extensions for G.709 Optical
Transport Networks Control", RFC 4328, January 2006.
[RFC4606] Mannie, E. and D. Papadimitriou, "Generalized Multi-
Protocol Label Switching (GMPLS) Extensions for
Synchronous Optical Network (SONET) and Synchronous
Digital Hierarchy (SDH) Control", RFC 4606, August 2006.
[RFC4802] Nadeau, T. and A. Farrel, "Generalized Multiprotocol Label
Switching (GMPLS) Traffic Engineering Management
Information Base", RFC 4802, February 2007.
[RFC4872] Lang, J., Rekhter, Y., and D. Papadimitriou, "RSVP-TE
Extensions in Support of End-to-End Generalized Multi-
Margaria, et al. Expires January 16, 2014 [Page 32]
Internet-Draft PCEP Ext for GMPLS July 2013
Protocol Label Switching (GMPLS) Recovery", RFC 4872, May
2007.
[RFC4873] Berger, L., Bryskin, I., Papadimitriou, D., and A. Farrel,
"GMPLS Segment Recovery", RFC 4873, May 2007.
[RFC5440] Vasseur, JP. and JL. Le Roux, "Path Computation Element
(PCE) Communication Protocol (PCEP)", RFC 5440, March
2009.
[RFC5520] Bradford, R., Vasseur, JP., and A. Farrel, "Preserving
Topology Confidentiality in Inter-Domain Path Computation
Using a Path-Key-Based Mechanism", RFC 5520, April 2009.
[RFC5521] Oki, E., Takeda, T., and A. Farrel, "Extensions to the
Path Computation Element Communication Protocol (PCEP) for
Route Exclusions", RFC 5521, April 2009.
[RFC5541] Le Roux, JL., Vasseur, JP., and Y. Lee, "Encoding of
Objective Functions in the Path Computation Element
Communication Protocol (PCEP)", RFC 5541, June 2009.
[RFC6001] Papadimitriou, D., Vigoureux, M., Shiomoto, K., Brungard,
D., and JL. Le Roux, "Generalized MPLS (GMPLS) Protocol
Extensions for Multi-Layer and Multi-Region Networks (MLN/
MRN)", RFC 6001, October 2010.
[RFC6003] Papadimitriou, D., "Ethernet Traffic Parameters", RFC
6003, October 2010.
[RFC6205] Otani, T. and D. Li, "Generalized Labels for Lambda-
Switch-Capable (LSC) Label Switching Routers", RFC 6205,
March 2011.
[RFC6387] Takacs, A., Berger, L., Caviglia, D., Fedyk, D., and J.
Meuric, "GMPLS Asymmetric Bandwidth Bidirectional Label
Switched Paths (LSPs)", RFC 6387, September 2011.
9.2. Informative References
[I-D.ietf-pce-gmpls-aps-req]
Otani, T., Ogaki, K., Caviglia, D., Zhang, F., and C.
Margaria, "Requirements for GMPLS applications of PCE",
draft-ietf-pce-gmpls-aps-req-08 (work in progress), June
2013.
[I-D.ietf-pce-inter-layer-ext]
Margaria, et al. Expires January 16, 2014 [Page 33]
Internet-Draft PCEP Ext for GMPLS July 2013
Oki, E., Takeda, T., Farrel, A., and F. Zhang, "Extensions
to the Path Computation Element communication Protocol
(PCEP) for Inter-Layer MPLS and GMPLS Traffic
Engineering", draft-ietf-pce-inter-layer-ext-07 (work in
progress), July 2012.
[I-D.ietf-pce-wson-routing-wavelength]
Lee, Y., Bernstein, G., Martensson, J., Takeda, T.,
Tsuritani, T., and O. Dios, "PCEP Requirements for WSON
Routing and Wavelength Assignment", draft-ietf-pce-wson-
routing-wavelength-09 (work in progress), June 2013.
[RFC4655] Farrel, A., Vasseur, J., and J. Ash, "A Path Computation
Element (PCE)-Based Architecture", RFC 4655, August 2006.
[RFC4657] Ash, J. and J. Le Roux, "Path Computation Element (PCE)
Communication Protocol Generic Requirements", RFC 4657,
September 2006.
[RFC6123] Farrel, A., "Inclusion of Manageability Sections in Path
Computation Element (PCE) Working Group Drafts", RFC 6123,
February 2011.
Authors' Addresses
Cyril Margaria (editor)
Coriant GmbH
St Martin Strasse 76
Munich 81541
Germany
Phone: +49 89 5159 16934
Email: cyril.margaria@coriant.com
Oscar Gonzalez de Dios (editor)
Telefonica Investigacion y Desarrollo
C/ Emilio Vargas 6
Madrid 28043
Spain
Phone: +34 91 3374013
Email: ogondio@tid.es
Margaria, et al. Expires January 16, 2014 [Page 34]
Internet-Draft PCEP Ext for GMPLS July 2013
Fatai Zhang (editor)
Huawei Technologies
F3-5-B R&D Center, Huawei Base
Bantian, Longgang District
Shenzhen 518129
P.R.China
Email: zhangfatai@huawei.com
Margaria, et al. Expires January 16, 2014 [Page 35]