•
Both PCE/PCC functionality runs on routers
•
PCE function router need special image or official image with SMU installed
•
PCE server could be external third party PCE server, such as Cariden
Stateful PCE provides support for these following request types and objects:
•
Request types
◦
PCReq
—
requests used by current stateless PCE implementation
◦
PCCreate
—
LSP instantiation requests
◦
PCUpd
—
LSP update requests
•
LSP Objects
◦
Operational flag
◦
Delegation flag
◦
Remove flag
◦
Symbolic path name
◦
LSP Identifiers
•
Path list
◦
ERO
Stateful PCE State Reporting
State reporting refers to the PCC sending information to PCEs about the state of LSPs. This is done as state
changes occur and is used to keep PCEs informed of changes to the LSP as they occur. State reporting is also
used as part of
state synchronization
and
delegation
.
A state report is a message sent by a PCC to a PCE reporting on the state of one or more TE tunnels. This
allows the PCE to stay abreast of changes as they occur. Reports are triggered when the PCE needs to be
informed of state. These occur when:
•
State synchronization happens
•
The PCC attempts to delegate control of a tunnel to a PCE
•
The PCC revokes control of a tunnel from a PCE
•
The PCC deletes a tunnel
•
A signalling error occurs on a tunnel
•
Reportable information about a tunnel changes
Cisco IOS XR MPLS Configuration Guide for the Cisco CRS Router, Release 5.1.x
209
Implementing MPLS Traffic Engineering
Stateful Path Computation Element