RFC 7420
Path Computation Element Communication Protocol (PCEP) Management Information Base (MIB) Module
Internet Engineering Task Force (IETF) A. Koushik Request for Comments: 7420 Brocade Communications, Inc. Category: Standards Track E. Stephan ISSN: 2070-1721 Orange Q. Zhao Huawei Technology D. King Old Dog Consulting J. Hardwick Metaswitch December 2014 Path Computation Element Communication Protocol (PCEP) Management Information Base (MIB) ModuleAbstract
This memo defines a portion of the Management Information Base (MIB) for use with network management protocols in the Internet community. In particular, it describes managed objects for modeling of the Path Computation Element Communication Protocol (PCEP) for communications between a Path Computation Client (PCC) and a Path Computation Element (PCE), or between two PCEs. 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/rfc7420.
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.Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 3 1.1. Requirements Language . . . . . . . . . . . . . . . . . . 3 1.2. Terminology . . . . . . . . . . . . . . . . . . . . . . . 3 2. The Internet-Standard Management Framework . . . . . . . . . 4 3. PCEP MIB Module Architecture . . . . . . . . . . . . . . . . 4 3.1. pcePcepEntityTable . . . . . . . . . . . . . . . . . . . 4 3.2. pcePcepPeerTable . . . . . . . . . . . . . . . . . . . . 5 3.3. pcePcepSessTable . . . . . . . . . . . . . . . . . . . . 5 3.4. PCEP Notifications . . . . . . . . . . . . . . . . . . . 6 3.5. Relationship to Other MIB Modules . . . . . . . . . . . . 6 3.6. Illustrative Example . . . . . . . . . . . . . . . . . . 7 4. Object Definitions . . . . . . . . . . . . . . . . . . . . . 8 4.1. PCE-PCEP-MIB . . . . . . . . . . . . . . . . . . . . . . 8 5. Security Considerations . . . . . . . . . . . . . . . . . . . 49 6. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 50 7. References . . . . . . . . . . . . . . . . . . . . . . . . . 50 7.1. Normative References . . . . . . . . . . . . . . . . . . 50 7.2. Informative References . . . . . . . . . . . . . . . . . 51 Appendix A. PCEP MIB Module Example . . . . . . . . . . . . . . 52 A.1. Contents of PCEP MIB Module at PCE2 . . . . . . . . . . . 53 A.2. Contents of PCEP MIB Module at PCCb . . . . . . . . . . . 60 Acknowledgements . . . . . . . . . . . . . . . . . . . . . . . . 64 Contributors . . . . . . . . . . . . . . . . . . . . . . . . . . 64 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 65
1. Introduction
The PCE defined in [RFC4655] is an entity that is capable of computing a network path or route based on a network graph and applying computational constraints. A PCC may make requests to a PCE for paths to be computed. PCEP is the communication protocol between a PCC and PCE and is defined in [RFC5440]. PCEP interactions include path computation requests and path computation replies as well as notifications of specific states related to the use of a PCE in the context of Multiprotocol Label Switching (MPLS) and Generalized MPLS (GMPLS) Traffic Engineering (TE). This memo defines a portion of the MIB for use with network management protocols in the Internet community. In particular, it defines a MIB module that can be used to monitor PCEP interactions between a PCC and a PCE, or between two PCEs. The scope of this document is to provide a MIB module for the PCEP base protocol defined in [RFC5440]. Extensions to the PCEP base protocol are beyond the scope for this document.1.1. 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 BCP 14 [RFC2119].1.2. Terminology
This document uses the terminology defined in [RFC4655] and [RFC5440]. In particular, it uses the following acronyms. o Path Computation Request (PCReq) message. o Path Computation Reply (PCRep) message. o Notification (PCNtf) message. o Error (PCErr) message. o Request Parameter (RP) object. o Synchronization Vector (SVEC) object. o Explicit Route Object (ERO).
This document uses the term "PCEP entity" to refer to a local PCEP speaker, "peer" to refer to a remote PCEP speaker, and "PCEP speaker" where it is not necessary to distinguish between local and remote.2. The Internet-Standard Management Framework
For a detailed overview of the documents that describe the current Internet-Standard Management Framework, please refer to section 7 of RFC 3410 [RFC3410]. Managed objects are accessed via a virtual information store, termed the Management Information Base or MIB. MIB objects are generally accessed through the Simple Network Management Protocol (SNMP). Objects in the MIB are defined using the mechanisms defined in the Structure of Management Information (SMI). This memo specifies a MIB module that is compliant to the SMIv2, which is described in STD 58, RFC 2578 [RFC2578], STD 58, RFC 2579 [RFC2579], and STD 58, RFC 2580 [RFC2580].3. PCEP MIB Module Architecture
The PCEP MIB module contains the following information: a. PCE and PCC local entity status (see pcePcepEntityTable). b. PCEP peer information (see pcePcepPeerTable). c. PCEP session information (see pcePcepSessTable). d. Notifications to indicate PCEP session changes. The PCEP MIB module is limited to "read-only" access except for pcePcepNotificationsMaxRate, which is used to throttle the rate at which the implementation generates notifications.3.1. pcePcepEntityTable
The PCEP MIB module may contain status information for multiple logical local PCEP entities. There are several scenarios in which there may be more than one local PCEP entity, including the following. o A physical router, which is partitioned into multiple virtual routers, each with its own PCC. o A PCE device that front ends a cluster of compute resources, each with a different set of capabilities that are accessed via different IP addresses.
The pcePcepEntityTable contains one row for each local PCEP entity. Each row is read-only and contains current status information, plus the PCEP entity's running configuration. The pcePcepEntityTable is indexed by pcePcepEntityIndex, which also acts as the primary index for the other tables in this MIB module.3.2. pcePcepPeerTable
The pcePcepPeerTable contains one row for each peer that the local PCEP entity knows about. Each row is read-only and contains information to identify the peer, the running configuration relating to that peer, and statistics that track the messages exchanged with that peer and its response times. A PCEP speaker is identified by its IP address. If there is a PCEP speaker in the network that uses multiple IP addresses, then it looks like multiple distinct peers to the other PCEP speakers in the network. The pcePcepPeerTable is indexed first by pcePcepEntityIndex, then by pcePcepPeerAddrType and pcePcepPeerAddr. This indexing structure allows each local PCEP entity to report its own set of peers. Since PCEP sessions can be ephemeral, pcePcepPeerTable tracks a peer even when no PCEP session currently exists to that peer. The statistics contained in pcePcepPeerTable are an aggregate of the statistics for all successive sessions to that peer. To limit the quantity of information that is stored, an implementation MAY choose to discard a row from pcePcepPeerTable if and only if no PCEP session exists to the corresponding peer.3.3. pcePcepSessTable
The pcePcepSessTable contains one row for each PCEP session that the PCEP entity (PCE or PCC) is currently participating in. Each row is read-only and contains the running configuration that is applied to the session, plus identifiers and statistics for the session. The statistics in pcePcepSessTable are semantically different from those in pcePcepPeerTable since the former applies to the current session only, whereas the latter is the aggregate for all sessions that have existed to that peer. Although it is forbidden per [RFC5440] to have more than one active PCEP session between a given pair of PCEP entities at any one time, there is a window during session establishment where the
pcePcepSessTable may contain two rows for a given peer, one representing a session initiated by the local PCEP entity and one representing a session initiated by the peer. If either of these sessions reaches an active state, then the other is discarded. The pcePcepSessTable is indexed first by pcePcepEntityIndex, then by pcePcepPeerAddrType and pcePcepPeerAddr, and finally by pcePcepSessInitiator. This indexing structure allows each local PCEP entity to report its own set of active sessions. The pcePcepSessInitiator index allows two rows to exist transiently for a given peer, as discussed above.3.4. PCEP Notifications
The PCEP MIB module contains notifications for the following conditions. a. pcePcepSessUp: PCEP session has gone up. b. pcePcepSessDown: PCEP session has gone down. c. pcePcepSessLocalOverload: Local PCEP entity has sent an overload PCNtf on this session. d. pcePcepSessLocalOverloadClear: Local PCEP entity has sent an overload-cleared PCNtf on this session. e. pcePcepSessPeerOverload: Peer has sent an overload PCNtf on this session. f. pcePcepSessPeerOverloadClear: Peer has sent an overload-cleared PCNtf on this session.3.5. Relationship to Other MIB Modules
The PCEP MIB module imports the following textual conventions from the INET-ADDRESS-MIB defined in RFC 4001 [RFC4001]: o InetAddressType o InetAddress PCEP relies on existing protocols that have specialized MIB objects to monitor their own activities. Consequently, this document considers that the monitoring of underlying protocols is out of scope of the PCEP MIB module.
3.6. Illustrative Example
The following diagram illustrates the relationships between pcePcepEntityTable, pcePcepPeerTable, and pcePcepSessTable. Index by: pcePcepEntityIndex +--------------+ Index by: |pcePcepEntity | pcePcepEntityIndex, |Table | pcePcepPeerAddrType, +--------------+ pcePcepPeerAddr |pcePcepEntity | |Entry |<----* +--------------+ | +------------+ Index by: | | | |pcePcepPeer | pcePcepEntityIndex, | |<-* | |Table | pcePcepPeerAddrType, +--------------+ | | +------------+ pcePcepPeerAddr, | *--|PcePcepPeer | pcePcepSessInitiator | | |Entry |<-----* | | +------------+ | +------------+ | *--| | | |pcePcepSess | | | |<----*| |Table | | +------------+ || +------------+ *-----| | |*-|pcePcepSess | | | |<--* | |Entry | | +------------+ | | +------------+ *-----| | | *--| | | [1] | | | | +------------+ | +------------+ *----| | | | | | +------------+ *----| [2] | | | +------------+ [1]: A peer entry with no current session. [2]: Two sessions exist during a window in session initialization.
(next page on part 2)
