PCE Path Profiles

PCEP speakers advertise their capability to support path profiles during the session initialization phase. They include the PATH-PROFILE-CAPABILITY TLV defined in as part of the OPEN object. A PCEP speaker can only signal a path profile if both speakers advertised this capability. A speaker MUST send a PCErr message with Error-Type=4 (Not supported object), Error-value=1 (Not supported object class) and close the session if it receives a message with a path profile id, it supports the extensions in this document and both speakers did not advertise this capability.

A PCC MAY include a PATH-PROFILE object when sending a PCReq message. The PCE uses the path profile id to select the parameters to fullfil the request. The means by which the PCC learns about a particular path profile id and decides to include it in a PCReq message are outside the scope of this document. Similarly, the means by which the PCE selects a set of parameters based on the profile id for a specific request are outside the scope of this document. The PCE may be stateful or stateless. A PCE may receive a path computation request with an unknown or invalid path profile id. The PCE sends a PCErr message with Error-Type=[TBA] (PATH-PROFILE Error), Error-value=1 (Unknown path profile) if the path profile id is not known to the PCE. The PCE sends a PCErr message with Error-Type=[TBA] (PATH-PROFILE Error), Error-value=2 (Invalid path profile) if the PCE knows about the path profile id, but considers the request invalid. The profile may be invalid because of the path type, the PCEP session type or for the originating PCC. The PCE will determine whether to consider any additional optional objects included in a PCReq message based on policy. As illustrated in and , the PCC MAY include other optional objects along with a PATH-PROFILE object as part of a path computation request. The PCC will use the processing-rule (P) flag in the common object header to signal whether it considers those objects mandatory or optional when the PCE performs path computation. Those objects may overlap with the path parameters that the PCE associates with the path profile id. PCE policy may place different kinds of restrictions on PCReq messages that include a PATH-PROFILE object and additional parameters. A PCE MUST send an error message if it receives a request with optional objects signaled as mandatory (P flag = 1) for path computation and PCE policy does not allow such behavior from the originating PCC. In that case, the PCE sends a PCErr message with Error-Type=[TBA] (PATH-PROFILE Error), Error-value=3 (Unexpected mandatory object). If the objects are signaled as optional (P flag = 0) for path computation, the PCE will decide based on policy whether to consider them or not. When sending the PCRep message for the request, the PCE will use the ignore (I) flag in the common object header to indicate to the PCC whether an object was ignored.

defines the basic structure of a PCReq message for point-to-point paths. This documents extends the message format as follows:

::= [] ]]> where:

::=[] ::=[] ::=

[] [] ]]>

where: <path-computation> is the list of optional objects used for path computation as defined initially in and modified in subsequent PCEP extensions. If present in a PCReq message, the PATH-PROFILE object MUST be the first optional object in the request portion of the message.

defines the basic structure of a PCReq message for point-to-multipoint paths. This documents extends the message format as follows: TBD

A PCE MAY include a PATH-PROFILE object when sending a PCInitiate message as defined in . The PCC can use the path profile id to select local behavior to apply to the path. The means by which the PCE selects a profile id for a specific PCInitiate message are outside the scope of this document. Similarly, the means by which the PCC selects the local behavior to apply to a path based on a path profile id are outside the scope of this document. defines the basic structure of a PCInitiate message. This documents extends the message format as follows:

::=

Where: ::= [] ::= (| ) ::=

[PATH-PROFILE> [] ::= ]]>

where: <attribute-list> is defined in and extended by PCEP extensions.