First of all, sorry for my bad english... :) This thread: http://www.openser.org/pipermail/users/2006-June/005012.html says I can't use forward(), for failover, I have to use t_relay, which means that the server must be statefull. But the thing is, i wouldn't like to maintain transactions state in the server, due to the high memory usage. Is it true? Can't I have failover support with forward()? Santiago Soares Fone: (41) 8488-0537 On Thu, Mar 11, 2010 at 11:33 AM, Geoffrey Mina <geoffreymina(a)gmail.com> wrote:

Hello, On 03/11/2010 10:11 PM, Iñaki Baz Castillo wrote: just to confirm what Inaki says that you need tm for doing failover and give you a bit more insights to understand why. In stateless mode, the sip message is received, processed via config (e.g., in your case select a destination), relayed and completely forgotten. Reply comes, the sip router takes the Via header stack and routes it to origin. Nothing exists about the SIP request in sip router when the reply is processed. In stateful mode, the initial request is saved in memory, when the reply comes it, tm module matches what is the corresponding request. If the reply code was negative, via failure_route you can get the initial request back for processing and re-send it to new destination. The performances of tm are very good, with latest 3.0 one more time improved a lot. Also note that transaction means "request to final reply", not "beginning of call to end of call". So memory is used from the moment the initial invite comes in until the call is answered, canceled or time-out. During the time call is active, no memory is consumed. Cheers, Daniel -- Daniel-Constantin Mierla Kamailio SIP Router Masterclass, Berlin, March 22-26, 2010 * http://www.asipto.com/index.php/sip-router-masterclass/