A YANG Data Model for Segment Routing in IPv6 (SRv6) support in Path Computation Element Communications Protocol (PCEP)Huawei TechnologiesHuawei Campus, No. 156 Beiqing Rd.Beijing100095Chinachengli13@huawei.comCisco Systems, Inc.2000 Innovation DriveKanataOntarioK2K 3E8Canadamsiva@cisco.com
Routing
PCE Working GroupThis document augments a YANG data model for the management of
Path Computation Element communications Protocol (PCEP) for
communications between a Path Computation Client (PCC) and a Path
Computation Element (PCE), or between two PCEs in support for Segment Routing in IPv6. The data model
includes configuration data and state data (status information and
counters for the collection of statistics).The Path Computation Element (PCE) defined in
is an entity that is capable of computing a network path or route
based on a network graph, and applying computational constraints.
A Path Computation Client (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 . 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).
specifies extensions to PCEP to enable stateful control of MPLS TE LSPs. extends
to support SR for IPv6 data plane. defines a YANG data model
for the management of PCEP speakers. This document contains a specification of the PCEP-SRv6 YANG module,
"ietf-pcep-srv6" which provides the PCEP-SRv6 data
model.The PCEP operational state is included in the same tree as the PCEP
configuration consistent with Network Management Datastore
Architecture .
The origin of the data is indicated as per the origin metadata
annotation.The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL
NOT", "SHOULD", "SHOULD NOT", "RECOMMENDED", "NOT RECOMMENDED",
"MAY", and "OPTIONAL" in this document are to be interpreted as
described in BCP 14 when, and only when, they
appear in all capitals, as shown here.
This document also uses the following terms defined in
:
PCEP entity: a local PCEP speaker.
PCEP peer: to refer to a remote PCEP speaker.
PCEP speaker: where it is not necessary to distinguish between local
and remote.
Further, this document also uses the following terms defined in
:
Stateful PCE, Passive Stateful PCE, Active Stateful PCE
Delegation, Revocation, Redelegation
LSP State Report, Path Computation Report message (PCRpt).LSP State Update, Path Computation Update message (PCUpd). :
PCE-initiated LSP, Path Computation LSP Initiate Message (PCInitiate). :
Path Setup Type (PST). :
Segment Routing (SR). :
Segment Routing in IPv6 (SRv6).A simplified graphical representation of the data model is used in this
document. The meaning of the symbols in these diagrams is defined in .
In this document, names of data nodes and other data
model objects are often used without a prefix, as long as it is clear
from the context in which YANG module each name is defined.
Otherwise, names are prefixed using the standard prefix associated
with the corresponding YANG module, as shown in .PrefixYANG moduleReferencete-typesietf-te-typespietf-pcepstietf-srv6-typesThe PCEP-SRv6 YANG module defined in this document has all the common
building blocks for the PCEP-SRv6 extension.
RFC Ed.: In this section, replace all occurrences of 'XXXX' with the
actual RFC number and all occurrences of the revision date below with
the date of RFC publication (and remove this note).The YANG module defined in this document is designed to be accessed via
network management protocol such as NETCONF
or RESTCONF . The lowest NETCONF layer is the secure
transport layer and the mandatory-to-implement secure transport is
SSH . The lowest RESTCONF layer is HTTPS, and the
mandatory-to-implement secure transport is TLS The NETCONF access control model provides
the means to restrict access for particular NETCONF or RESTCONF users to a
pre-configured subset of all available NETCONF or RESTCONF protocol
operations and content.There are a number of data nodes defined in the YANG module which are
writable/creatable/deletable (i.e., config true, which is the
default). These data nodes may be considered sensitive or vulnerable
in some network environments. Write operations (e.g., <edit-config>)
to these data nodes without proper protection can have a negative
effect on network operations. These are the subtrees and data nodes and
their sensitivity/vulnerability:
/p:pcep/p:entity/p:capability/ps:srv6 - configure local SRv6 capability and parameters./p:pcep/p:entity/p:peers/p:peer/p:capability/ps:srv6 - configure peer's SRv6 capability and parameters.Unauthorized access to above list can adversely affect the
PCEP session between the local entity and the peers. This may
lead to inability to compute new paths, stateful operations on
the delegated as well as PCE-initiated LSPs.Some of the readable data nodes in this YANG module may be considered
sensitive or vulnerable in some network environments. It is thus important
to control read access (e.g., via get, get-config, or notification) to
these data nodes. These are the subtrees and data nodes and their
sensitivity/vulnerability:
/p:pcep/p:entity/p:lsp-db/p:lsp/ps:srv6 - The SRv6 SID in the network. Unauthorized access to
this could provide the all path and network usage information.This document registers a URI in the "IETF XML Registry"
.
Following the format in RFC 3688, the following registration has been
made.
urn:ietf:params:xml:ns:yang:ietf-pcep-srv6The PCE WG of the IETF.N/A; the requested URI is an XML namespace.This document registers a YANG module in the "YANG Module Names"
registry .
The authors would like to thank Dhruv Dhody for the initial YANG model.