Thanks Arun and Ulrich for your suggestion.
I was stuck in some other issue that's why bit late to reply.
Ulrich, our router is installed and configured even few weeks back it is working fine.
can you please give me a hint from where I can start debugging? And one more point I want to add here, for all our SAP system it is stop working at same time.
Arun, can you please explain me how I check the correct entries for message server? I think might be this is the possible solution for my problem as all the OSS connection stop working at same time.
Thanks in advance.
Regards,
Dipesh Gupta