Hello, On 7/1/10 10:41 AM, jerome.marchet(a)orange-ftgroup.com wrote: the goals of topoh module were set to offer topology hiding functionality within a proxy, so right now it offers: - topology hiding even for transaction stateless mode (not even tm is required) - transparent mode for config file - inside the config, you will see the plain sip message, without any encodings - it survives restarts - restarting the sip server has no impact on ongoing calls - works over distributed farm of sip servers - encoding can be done by one instance, decoding works fine on another one that shares the same secret. This is good for HA, where invite was processed by active server and the bye happens to be processed by standby because HA switched. Another case is for load balancing, no need to care of routing messages within a call to same box - high performance for call processing - it can easily handle thousands of call setups per second, which is hard to achieve in b2bua What you suggest is a b2bua and there are many options already available. For example SEMS (SIP Express Media Server) has an application for sip signaling only back to back user agent. Also, same can be achieved more or less with asterisk or freeswitch. Cheers, Daniel -- Daniel-Constantin Mierla http://www.asipto.com/