Conveying Vendor-Specific Constraints in the Path Computation Element Communication Protocol
RFC 7150
Document | Type |
RFC - Proposed Standard
(March 2014; No errata)
Obsoleted by RFC 7470
|
|
---|---|---|---|
Authors | Fatai Zhang , Adrian Farrel | ||
Last updated | 2018-12-20 | ||
Replaces | draft-farrel-pce-vendor-constraints | ||
Stream | IETF | ||
Formats | plain text html pdf htmlized bibtex | ||
Reviews | |||
Stream | WG state | Submitted to IESG for Publication | |
Document shepherd | Julien Meuric | ||
Shepherd write-up | Show (last changed 2013-10-31) | ||
IESG | IESG state | RFC 7150 (Proposed Standard) | |
Consensus Boilerplate | Yes | ||
Telechat date | |||
Responsible AD | Stewart Bryant | ||
Send notices to | (None) | ||
IANA | IANA review state | IANA OK - Actions Needed | |
IANA action state | RFC-Ed-Ack |
Internet Engineering Task Force (IETF) F. Zhang Request for Comments: 7150 Huawei Category: Standards Track A. Farrel ISSN: 2070-1721 Juniper Networks March 2014 Conveying Vendor-Specific Constraints in the Path Computation Element Communication Protocol Abstract The Path Computation Element communication Protocol (PCEP) is used to convey path computation requests and responses both between Path Computation Clients (PCCs) and Path Computation Elements (PCEs) and between cooperating PCEs. In PCEP, the path computation requests carry details of the constraints and objective functions that the PCC wishes the PCE to apply in its computation. This document defines a facility to carry vendor-specific information in PCEP using a dedicated object and a new Type-Length-Variable that can be carried in any existing PCEP object. Status of This Memo This is an Internet Standards Track document. This document is a product of the Internet Engineering Task Force (IETF). It represents the consensus of the IETF community. It has received public review and has been approved for publication by the Internet Engineering Steering Group (IESG). Further information on Internet Standards is available in Section 2 of RFC 5741. Information about the current status of this document, any errata, and how to provide feedback on it may be obtained at http://www.rfc-editor.org/info/rfc7150. Zhang & Farrel Standards Track [Page 1] RFC 7150 Vendor-Specific Constraints in PCE March 2014 Copyright Notice Copyright (c) 2014 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. 1. Introduction A Path Computation Element (PCE) is an entity (component, application, or network node) that is capable of computing a network path or route based on a network graph and applying computational constraints. An architecture for the use of PCEs is defined in [RFC4655]. The Path Computation Element communication Protocol (PCEP) is defined in [RFC5440] to exchange path computation requests and responses between Path Computation Clients (PCCs) and PCEs. It is also used between cooperating PCEs. Path computations performed by a PCE depend on a set of constraints indicated by the PCC. These constraints include the endpoints of the path to compute (source and destination) and may include other simple constraints such as bandwidth requirements and metric maxima (for example, a maximum threshold for the hop count or the Traffic Engineering (TE) metric of the computed path). The PCE also needs to use an objective function to qualify the path it selects as meeting the requirements of the PCC. The PCE may have a default objective function, but the PCC can also indicate which objective function it wants applied by placing an Objective Function object in the path computation request message [RFC5541]. A core set of objective functions to be supported in PCEP messages is defined in the base PCEP requirements [RFC4657], and [RFC5541] defines each of these functions as an abstract formula. The registry of codepoints used to indicate objective functions is managed by IANA and new assignments can be made according to "IETF Review" and "First Come First Served" policies [RFC5226]. PCE implementations may also choose to offer proprietary, vendor-specific Zhang & Farrel Standards Track [Page 2] RFC 7150 Vendor-Specific Constraints in PCE March 2014 objective functions, and there is scope for this within the codepoint registry created by [RFC5541] using the codepoints that are flagged as "Reserved for Private Use". Proprietary objective functions may operate on non-standard constraints or metrics. The PCEP METRIC Object defined in [RFC5440] has scope for the definition of new, standardized metrics, but no facility for the definition of vendor-specific metrics. At the same time, there is no mechanism in PCEP for carrying other, more complex, vendor-specific information.Show full document text