PCE working group Q. Wu Internet-Draft Huawei Intended status: Standards Track July 15, 2013 Expires: January 16, 2014 OSPF extension for priority allocation support in the PCE discovery draft-wu-pce-discovery-priority-allocation-00 Abstract Each network domain may contain multiple PCE servers. It provides redundancy to the PCCs in the event of a server failure. However load balance decision is made by PCC,it doesn't enable real load balance across the PCE servers if PCC still tries PCE one by one and PCE doesn't indicate the load status to the PCC. This document proposes new PCE discovery sub-TLV that can be announced as attribute in the OSPF advertisement (defined in [RFC5088 ]) to distribute priority information. 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 Wu Expires January 16, 2014 [Page 1] Internet-Draft OSPF for PCE priority July 2013 to this document. Code Components extracted from this document must include Simplified BSD License text as described in Section 4.e of the Trust Legal Provisions and are provided without warranty as described in the Simplified BSD License. Table of Contents 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 3 2. Conventions used in this document . . . . . . . . . . . . . . . 4 3. PCE-ALLOCATION-PRIORITY Sub-TLV for PCE Load Balancing . . . . 5 3.1. Use of PCE-ALLOCATION-PRIORITY sub-TLV for PCE discovery . . . . . . . . . . . . . . . . . . . . . . . . . 5 4. Security Considerations . . . . . . . . . . . . . . . . . . . . 6 5. IANA Considerations . . . . . . . . . . . . . . . . . . . . . . 7 6. Normative References . . . . . . . . . . . . . . . . . . . . . 8 Author's Address . . . . . . . . . . . . . . . . . . . . . . . . . 9 Wu Expires January 16, 2014 [Page 2] Internet-Draft OSPF for PCE priority July 2013 1. Introduction Usually a single PCE server sits per domain in the nework. The PCE server disseminates its address in the network using OSPF [RFC5088] or ISIS [RFC5089] and the PCCs connect to it automatically. However in some cases, each network domain may contain multiple PCE servers. It provides redundancy to the PCCs in the event of a server failure. However load balance decision is made by PCC,it doesn't enable real load balance across the PCE servers if PCC still tries PCE one by one and PCE doesn't indicate the load status to the PCC (e.g., the number of incoming requests that have already targeted to the PCE). This document proposes new PCE discovery TLV that can be announced as attribute in the OSPF advertisement (defined in [RFC5088 ]) to distribute priority information. Wu Expires January 16, 2014 [Page 3] Internet-Draft OSPF for PCE priority July 2013 2. Conventions used in this document The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this document are to be interpreted as described in RFC2119 [RFC2119]. Wu Expires January 16, 2014 [Page 4] Internet-Draft OSPF for PCE priority July 2013 3. PCE-ALLOCATION-PRIORITY Sub-TLV for PCE Load Balancing The PCE-Allocated-Priority sub-TLV is an optional sub-TLV used to indicate allocated priority of each PCE. The format of the sub-TLVs is identical to the TLV format used by the Traffic Engineering Extensions to OSPF [RFC3630]. It MAY be present within the PCED TLV. It MUST NOT be present more than once. If it appears more than once, only the first occurrence is processed and any others MUST be ignored. The value field of the PCE-ALLOCATED-PRIORITY sub-TLV is expressed as 32-bit unsigned integer value.. The format of the PCE-ALLOCATED-PRIORITY sub-TLV is as follows: 0 1 2 3 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Type = TBD | Length | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Allocated Priority | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ Type: TBD Length: 4 octets Value: This contains allocated priority value for each PCE server. The priority value can be allocated based on PCE load or incoming request to the PCE server. 3.1. Use of PCE-ALLOCATION-PRIORITY sub-TLV for PCE discovery Multiple servers can be present in a single network for redundancy in which case each PCE server is allocated with a priority value. The priority can be allocated based on PCE load (e.g., incoming request to the PCE server) announced as attribute in the OSPF advertisement. The PCC can be configured to use the highest priority PCE server that is available or specify the priority of a computation request when multiple PCEs has already been found using OSPF[RFC5088]. Wu Expires January 16, 2014 [Page 5] Internet-Draft OSPF for PCE priority July 2013 4. Security Considerations This document raises no new security issues beyond those described in [RFC5088]. Wu Expires January 16, 2014 [Page 6] Internet-Draft OSPF for PCE priority July 2013 5. IANA Considerations IANA maintains the registry for the TLVs. PCE-allocated-priority sub-TLV will require one new type code per sub-TLV defined in this document. Wu Expires January 16, 2014 [Page 7] Internet-Draft OSPF for PCE priority July 2013 6. Normative References [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate Requirement Levels", March 1997. [RFC5088] Le Roux, JL., "OSPF Protocol Extensions for Path Computation Element (PCE) Discovery", RFC 5088, January 2008. Wu Expires January 16, 2014 [Page 8] Internet-Draft OSPF for PCE priority July 2013 Author's Address Qin Wu Huawei 101 Software Avenue, Yuhua District Nanjing, Jiangsu 210012 China Email: sunseawq@huawei.com Wu Expires January 16, 2014 [Page 9]