CSPF algorithm is running by MPLS-TE or the extended ISIS/OSPF ?

[superkliko]

Hi,

Title says all, some resources mention MPLS-TE and some others ISIS/OSPF.

Thanks

[Nagendra Kumar Nainar]

Hi,

CSPF is an algorithm that uses the database populated by OSPF/ISIS to calculate a path using the constraints provided as input, convert the path to ERO and provide it to MPLS-TE which can use it to establish the LSP.

So OSPF/ISIS here can be considered as protocol that helps build the TE database, MPLS-TE can be considered as consumer and CSPF as a process that uses TE database and gives what MPLS-TE wants ;)

-Nagendra

[superkliko]

Thank you Nagendra,

The extended ISIS/OSPF are creating 2 DBs one for unicast LSDB and one for the TE-LSDB, then CSPF is using the TE-LSDB and TE-Constraints (user defined) to build the ERO, all good so far.

Still though not sure if CSPF running under the ISIS/OSPF or MPLS-TE process, I presume under the IGPs.

Regards