We sell, install and maintain Tadiran systems and have since the early 1980's. The IP provisioning is WONDERFUL!! We are also now doing Asterisk and MANY things that the Tadiran does very, very simply are not so simple in the Asterisk, ie. how many lines of code does it take in the Asterisk to simply toll restrict specific stations and allow others full access?? Secondly, while SOME of the components of the Asterisk are relatively inexpensive, much of this "free" system is NOT. Purchasing the right server/s, gateways etc. are NOT inexpensive and we often find that deploying a Tadiran to a IP environment is significantly LESS expensive and far more user friendly (Gawd, I HATE that term!!)
YES, the world of SIP telephony is upon us and will continue to be so, but until more telephone types (like most of us here) get into the game, feature function of these systems is going to be rough sledding for the end user.
