Farhan,
I would suggest to do Below Steps:
- Try to call Bank Service without using SAP PI and see how much time it takes to Respond and confirm if it is within timeout set in SAP PI.
- Considering you have Classical Scenario, I will check time taken at each pipeline step (Receiver Determination, xml Validation, Message Mapping, Technical Routing) in SXI_Monitor using Runtime/Trace.
- Once identified which step is taking more time I will restrict my debug to that area ( Also check if your Message Mapping is having any UDF/Java Mapping with infinite loop).
Also perform SLDCHECK to make sure my Proxy configuration is correct in ECC.
Thanks,
Sunil