Communication channels for EBP-SUS scenario (SRM server 5.0)

Hello All,

We are using SRM server 5.0 with XI 3.0.

This question is with reference to the supplier enablement scenario (Service procurement) using EBP-XI-SUS.

Have successfully transfered the integration scenario from the Integration repository and the business systems are in place.

XI creates 4 communication channels by defult (XI,RFC,HTTP & Idoc) for the business systems EBP & SUS. Scenario is not activated completely till the parameters are supplied for the communication channels.Shows Error in receiver determination(Comm. channel does not exist).

My question - Which communcation channels are used by this scenario??? XI, RFC or HTTP??? or all of them ???

Thanks in advance.

Pai