AT&T Migrating Phone Network to IP

prostoalex writes "Following the lead of Sprint and Telus, who are moving their telephone networks to IP, AT&T will spend $3 billion to migrate to an IP-based network. By the end of 2005 about 270 legacy systems will be retired." The article also notes how the current ratio of packet traffic to voice is already 8:1.

Comments

Bandwidth?

[lord_paladine]

As this article states, the bandwidth required for VoIP can be huge. I would seriously hope to see some more advanced algorithms or better yet, more bandwidth installed, before these systems become more heavily adopted.

Re:Bandwidth?

[Abcd1234]

Too bad your link refers to corporations using VoIP on their LAN/WAN as an alternative to traditional telephony. What we're talking about here is telephone operators using IP as a backbone transport (as opposed to voice over ATM VCs, etc). For telephone providers, VoIP has some excellent advantages, the most notable being consolidation of existing infrastructure (ie, being able to use the same lines for both voice and data).

Re:Bandwidth?

[phliar]

I used to work at a VoIP added-services provider. Received wisdom was that packet telephony was definitely the future, but 50-50 on whether or not IP was the right protocol for packet voice networks. One thing for sure is, in H.323 there's no point in using G.711 for voice -- a decent 10-12kbps codec will sound fine compared to the 64kbps that G.711 uses. I think that H.323 is sensitive to all kinds of parameters like comfort noise and silence suppression, you need to tune it to your network. In practice, it looks like well-tuned VoIP does take more bandwidth that good ol' PSTN, but the difference is not significant enough to justify running two kinds of networks.

However I worked at the software end, not VoIP network operations -- what do I know?

Re:What about VOIP

[silentbozo]

Depends on which phone companies you're talking about. The incumbent local exchange carriers (ILECs) make their money by charging customers outrageous monthly fees, and by charging long distance companies for terminating their calls at the local subscriber's telephone. They hate VOIP.

Carriers like AT&T, which sell primarily long distance, like VOIP since it saves them money, and could eventually allow them to bypass the ILECs entirely, since it turns voice calls into another internet data stream. They like VOIP.

Re:What about VOIP

[Tmack]

And how does VOIP change this??

VOIP is just another protocol. Most people seem to not realize that by the time their phoneline reaches the edge of their neighborhood, it has become a digital signal. The transition to VOIP is just natural progression. It allows more flexability, but will still require routers and switchtes to operate. Through these switches and routers is how the phone companies will keep track of calls. VOIP does NOT mean an end to phone numbers, providers, etc... Remember that most of the internet is carried by the ILEC networks on the same loops used to carry voice, just reonfigured slightly to allow pure data traffic. VOIP providers merely use these loops in the data configuration with routers that convert the analog voice signals to packets closer to the customer end than normal voice lines. VOIP merely abstracts the traffic type from the physical layer more than current SS7 and other protocols. VOIP is not simply PC-PC calls placed by IP address. VOIP is only a different protocol, central switches are still used to route calls and keep track of things, they just run more efficently (ie: 1 VOIP switch about the size of a 10k cisco can handle the entire call volume for a decent sized city (or 2) where currently several switches are required by the ILECs). Per-minute rates and such will still be acounted for. Phone providers will switch to VOIP mainly due to the relative simplicity and flexability of its stucture. VOIP is NOT what alot of people percieve, it is simply a new method of routing voice traffic that does not eliminate the need for routers/switches/etc...

TM

Skype

[westlake]

CNET has posted a Sept 11 newsmakers interview with Kazaa's Janus Friis promoting his P2P telephony app, Skype: Why VoIP is music to Kazaa's ear. The download (for Windows 2000 and XP only) can be found here: Skype beta.