[Serusers] Responses on the source port of the request

[mahesh]

Hi All,

I have a question regarding the functioning of the Iptel proxy server. As 
far as I know, only when there is "rports" field present in the "via" 
header field in a SIP request(INVITE for ex.), the proxy server should send 
the responses to the source port from which the request is sent. I would 
like to know if there is any other case in which the responses are sent to 
the source port instead of the VIA port.

Please provide me with the details on this.

thanks
Mahesh