Proxy receiver communication channel

Hi Experts,

When I am executing an interface in XI, I am getting the message in SXMB_MONI.

<SAP:Stack>Unable to create HTTP client (exception 1)</SAP:Stack>

The receiver is Proxy here. Where can I get the service number of R/3 system to enter in the XI receiver communication channel and what's the significance of this? I am using Proxy receiver adapter with URL address connection. I have given 8000 as the service number. Not sure whether this is right. What is the path prefix?

In the SXMB_ADM, do I need to maintain some parameters for proxy?

Thanks

Ricky