05 Jul FoIP Needs ENUM!
Two years ago we did some serious outbound testing with the cooperation of Copia International, one of our enterprise-fax server OEMs. Copia’s CopiaFacts is a full-function server for the enterprise, but it has a bunch of features that the mission-critical fax-broadcast guys find to be really helpful. So we were able to gather some very beneficial data as Copia performs evals for broadcast customers. Two years ago, Smart FoIP fell out of the data. Now, we’re doing it again, but this time we’re doing it as part of our work with the SIP Forum FoIP Task Group.
We’ve reported on several occasions how we installed CopiaFacts servers, based, of course, on BladeWare, in 13 global carrier locations in Europe, Asia, Australia, and North America. The results were sobering: Taking all failures into account, we only saw a nominal 50-percent completion rate. Whoa! What’s going on here? We knew carrier-based FoIP was “problematic”, but this is beyond that.
Yes, we fixed some BladeWare problems all this testing exposed, and yes, there were plenty of configuration problems in the on-ramp network, but the big problem appears to be trying to use SS-7, a call-routing system devised for the PSTN, to route calls that really needed IP-specific routing. That’s because the SS-7 network will throw an FoIP call that was transiting networks in T.38 mode into a TDM (PSTN) network without a second thought. Although this can work, nearly half the time is doesn’t. So, what’s the answer? Commetrex’ view is that the carriers need to move to ENUM as soon as possible.
Our testing over international routes has clearly shown that FoIP needs intelligent routing. This means each carrier’s routing algorithms must select a path that is not only IP, but supports T.38. ENUM is the first step to take as it will identify the destination IP network. Then, it’s up to the carriers involved to route the call over interconnects that have been proven to effectively support FoIP.