79th IETF – Beijing, November 2010
PCEP Extensions in support of WSON Signal Compatibility Constraints
<draft-lee-pce-wson-signal-compatibility-02.txt>
Young Lee [email protected] Huawei
Greg Bernstein [email protected] Networking
Jonas Martensson [email protected] Acreo
Takehiro [email protected]
Oscar Gonzalez de Dios [email protected]
79th IETF – Beijing, November 2010
Motivation/Background
Signal compatibility is an essential path computation constraint in path computation of WSON networks where network elements can be limited to processing WSON signals with specific characteristics and attributes.
Signal compatibility framework has been adopted into the current CCAMP WSON framework.
OSPF extension to support signal compatibility has been adopted as a CCAMP WG item in Hiroshima IETF: <draft-ietf-ccamp-wson-signal-compatibility-ospf-02.txt>
79th IETF – Beijing, November 2010
Signal Compatibility Constraints
On a high-level the following network element information would be required for the path computation element (PCE) to be able to compute a constrained path that satisfies signal compatibility and processing constraints:• Input Compatibility: the type of signals it can receive (modulation
types, rate, FEC types)• Regeneration Capability: the types of processing/enhancement it
can perform (1R, 2R, 3R)• The types of conversions it can perform (modulation types, FEC
types)• Output Format: the type of signals it can transmit (modulation
types, rate, FEC types)
79th IETF – Beijing, November 2010
Requirement #1
When requesting a path computation (PCReq) to PCE, the PCC should be able to indicate the following:• The acceptable signal attributes at the transmitter (at
the source): (i) modulation types; (ii) FEC types• The acceptable signal attributes at the receiver (at the
sink): (i) modulation types; (ii) FEC types• The Channel Spacing types at the source and the sink
(this is new information added in version 2)
79th IETF – Beijing, November 2010
Requirements #2
The PCE should be able to respond (PC Rep) to the PCC with the following:• The conformity of the requested optical characteristics associated
with the resulting LSP with the source, sink and NE along the LSP. • Additional LSP attributes modified along the path (e.g.,
modulation format change, etc.) • Special node processing with the resulting LSP (e.g., regeneration
point)• A list of Modulation/FEC types (per node identifier) in the ERO
object (or other suitable mechanism) in the case when more than one is compatible with all constraints
79th IETF – Beijing, November 2010
Summary & Next Steps
Adopt as a PCE WG document
Solicit more requirements and refine encoding