> From: Andy Pandaram > > Now, for this purpose, is it enough that > the distributor looks at just the Call-Id and not other tags > and parameters?
Actually, it is more important to use the from-tag than the Call-Id. Section 19.3 says that from-tags *must* provide 32 bits of cryptographic randomness, whereas section 8.1.1.4 only says that cryptographic randomness is recommended for Call-Ids. In practice, I would use both, though. If your distributor were to add a Via to each request, it would then be a proper proxy. But I don't see that there would be any problem not adding the Via, as long as you were sure that every target UA could route responses in the same way as the distributor. Subsequent requests will never go through the distributor because subsequent requests are routed according to the route-set for the dialog, and the distributor has not added a Record-Route. I think your biggest problem in practice is that if the distributor sends out requests with statistical randomness, there will be statistical fluctuations in the load balance between the destination UAs. There's no way to fix that problem without the distributor maintaining some state. You may also want to consider some sort of fail-over mechanism. Otherwise, if one of the UAs fails, 1/n of all incoming INVITES will fail. Dale _______________________________________________ Sip-implementors mailing list [email protected] http://lists.cs.columbia.edu/mailman/listinfo/sip-implementors
