To: dougjn who wrote (2610 ) 6/25/1998 3:27:00 PM From: Beltropolis Boy Respond to of 7342
>AT&T-TCI Plans Hinge on Unproven Technology doug. swell detailed post and i think you've answered mike's question regarding cablespan ip telephony: it'll be at least a year, possibly two, out. i took a look-see at the "Voice-on-the-net (VON), VoIP, Internet (IP) Telephony" board and found a nice post. i'm by no means a telecom techie; this cable guy definitely has more tools. following are his comments on the at&t-tci deal. note to john: he echos your power outage concerns. i feel like i've done a week's worth of due diligence in a half day. and i'm not even in yet. what am i thinking? swing, battuh battuh, swing! -chris. ----- "Over half of the TCI systems have yet to be upgraded to hybrid fiber coax with upstream communications bandwidth - this pretty well explains why wireless local loop [WLL] is part of the last mile equation in an AT&T / TCI network proposal. Even those TCI systems with both HFC and upstream bandwidth will struggle to make the coaxial return path clean enough to use for IP based voice and data services. TCI tried and discontinued voice services over a HFC network in Fremont, CA. Part of the problem was economics, and part of the problem was technical with return path noise ingress. Even more troublesome for AT&T than the overall technical level of TCI networks may turn out to be the less than stellar level of service and customer relations in many areas. It won't be an easy sell for AT&T/TCI local telephone service to customers who are not very satisfied with their TCI cable service. Of course, I cannot leave the subject of voice over IP via cable or WLL without pondering the power issue (one of my favorite subjects). Cable systems are still very vulnerable to service interruption during a power outage. Unlike copper pair telephone networks that are powered from the central office (or from remote digital loop carrier cabinets with at least 8 hours battery backup), most cable systems, including those with HFC, have limited battery reserve in case of power failures. Will the VoIP customer premises equipment be powered by the customer? If via WLL or cable modem, I think so."Message 5003775