Karen Brown, Senior Editor of CED Magazine has an informative piece on circuit switched technology:
A classic, oft-quoted line out of the Monty Python comedy The Search for the Holy Grail has a plague victim protesting, I m not dead yet. The same may well be said these days for circuit-switched telephony.
The technology that gave cable operators an entry to voice service is now rapidly being pushed aside for the latest technology darling, voice-over-Internet Protocol. But it doesn t appear circuit-switched technology is headed for the bone yard just yet circuit-switched gear still powers some of the most widely deployed services, and given conversion difficulties, they won t quickly convert to VoIP.
A good case-in-point is Charter Communications. Despite its focus on next-generation IP service, Charter has a constant-bitrate telephony market albeit a small one. The MSO inherited it as part of a system swap with then-AT&T Broadband to consolidate service in its hometown of St. Louis. The switched system included customer premise equipment, but not the switches that had been handled under a contract deal with AT&T Broadband s parent, AT&T Corp.
Once Charter acquired the network, it bought and installed a Nortel switch and its own backoffice system. On the subscriber side, Charter is using ARRIS Host Digital Terminals (HDTs) and NIUs to serve about 90,00 homes in the St. Louis market, with plans to soon add some MDU units. Given the maturity of that market, it doesn t make sense for now to move it over to IP voice, says Mark Barber, Charter s corporate vice president of telephony services.
We at this point and time don t have any intentions of converting those customers to IP, and the primary reason when you back up is this: we are almost at saturation in that market, meaning that in terms of penetration, we are north of 30 percent in that market, so the penetration is probably not going to be that much higher, he notes…
The blueprint for cable-based VoIP telephony is completed following the release of CableLabs PacketCable 1.2 specification, and the cable industry is moving toward the deployment of full end-to-end IP voice service over its new networks.
But circuit-switched, or constant-bit-rate (CBR) telephony is the long-established architecture, and operators such as Comcast and Cox continue to ring up subscribers based on circuit-switched architecture, says CED.
Comcast outlined its aggressive VoIP plans last month, after conducting extensive service trials in three markets and watching such other MSOs as Time Warner, Cablevision, Cox and Charter lead the charge. Comcast executives project 8 million VoIP subscribers in five years, achieving the same 20% penetration rate that they’re now approaching with high-speed data. Comcast will charge its VoIP subscribers a $39.95 a month for an unlimited calling package or pay as much as $54.95 a month without other cable services.
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