> Hi Expert > > SIP proxys can be groupped to work as a cluster. I have some questions on > it: > 1. Is there any RFC to describe the work flow for it? > 2. The cluster will use domain name to communicate other proxy. When proxy > send an INVITE messge to cluster with a IP address A, but later ACK message > use another IP address B. The call will fail. So how can cluster avoid such > a failure.
Please take a look at http://www1.cs.columbia.edu/~kns10/papers/sipload.pdf (section 4.2 and 4.5) for our cluster which uses Hash(user-id) to locate the proxy; thus all requests for one user/call will always go to the same second stage proxy block. For the first stage, which is *stateless*, it doesn't matter which proxy handles the ACK. For transaction stateful proxies with single stage cluster (similar to traditional web clustering), it becomes difficult to share state as you mentioned/hinted. But this is not impossible; e.g., the transaction state may be stored in the backend replicated database. _______________________________________________ Sip-implementors mailing list [email protected] https://lists.cs.columbia.edu/cucslists/listinfo/sip-implementors
