Re:I've actually done this. (Score 1)

Have you looked at CommuniGate Systems (aka Stalker Software)? There is a deployment in Sweden with 4-5 million users using their cluster. I guess it is too late for your choice but there is indeed an alternative to Openwave. http://www.stalker.com/CommuniGatePro I'm not directly affliated with them. I just built a few clusters using their software. ;-) Regards..