Stephen,
I'm not aware of any currently-available high-end SS7-to-C7 gateway grade switches from NT, or LU or the like, which also provide embedded H.323 or other IP telephony capabilities. I'm sure that they are in the works, but as far as any being released yet? I haven't heard of such.
However, some of the smaller programmable switches such as Summa Four (now a part of CSCO), and XLSW, along with a growing number of others, have been programmed and provisioned for both SS7-to-C7 conversion and VoIP on the back end. In turn, these switches either do a PSTN "hand off" or they attach to additional IP facilities for extending the call to a remote VoIP gateway, closer to the called party.
The determination here is dependent on many factors, but ordinarily this is dictated by (1) the extent and reach of the ITSP's domestic TCP/IP backbone network, and (2) the locations of the end points with respect to the international gateways.
Keep in mind that the larger switching entities in this space are substantial investments in both time and administration, and they must serve a greater number of services (mostly conventional in nature) than just the newer VoIPs. Therefore, they must be utilized optimally, so the price-performance outcome often points to using a discrete gateway, still, for the VoIP component (which is still a small fraction of the overall). In this fashion, they can thus use the larger remaining portion of the switch for domestic tandem and international gatewaying purposes, as well.
There's another thing to consider here, which is equally, probably more, important. And that is that many ITSPs would prefer to bypass the SS7/C7 gateway entirely at this time in order to take advantage of the regulatory leniency or forbearance that still exists.
Their preference at this time, instead, is to ride directly to their overseas destinations over a private IP backbone, or over a mesh of similar IP links, and handing off to the locals on a domestic (in-coutry) basis. This allows them to remain under the radar screen, as it were, thus permitting them side-step accounting rates and settlement issues. This is, in fact, how they are making most of their moolah nowadays, as it turns out.
Perhaps Jeff can elaborate on this if he is looking in here...? Any and all comments/corrections are welcome.
Regards, Frank Coluccio |
