FRAMINGHAM (09/26/2003) - AT&T Corp. this week announced a voice-over-IP option for its managed VPN service that promises multinational customers an easier way to support voice between sites around the world.
The service will let users integrate voice and data trunks, which provides for unified billing and might save money, although AT&T has not released pricing. And for customers already running voice on data networks, the option promises to reduce complexity and increase network flexibility by eliminating the need for permanent virtual circuits (PVC).
Frame relay PVCs, used to route traffic between fixed locations, can be unwieldy in a fully meshed data network supporting hundreds of sites. Because AT&T's Enhanced VPN service is based on Multi-protocol Label Switching, the new VoIP option means each site can be tied into the cloud and packets will be tagged as they enter and routed accordingly so customers don't have to predefine PVCs.
AT&T says the service will support on-net and off-net calling and will be available in 40 countries by year-end. Customers will be able to use existing frame relay, ATM or IP connections to access the service.
But customers looking for the VoIP features will have to be patient because the service will not be available for another seven to nine months - by the end of the second quarter.
"As the de facto incumbent vendor (AT&T) doesn't always have to be the first, but when it does roll out (a new technology) it has to work," says Zeus Kerravala, a vice president at The Yankee Group. He says AT&T might be lagging behind some competitors because it has invested time in improving customer service support. AT&T's Business Direct Web portal lets Enhanced VPN customers access real-time network performance statistics and view invoices.
Equant has offered multinational VoIP support with its managed VPN service that reaches approximately 240 countries for more than two years. "Equant is probably our prime competitor with this offer," says Joe Aibinder, director of AT&T voice over Internet services.
Equant's service, like AT&T's, is based on the International Telecommunication Union's (ITU) H.323 VoIP specification. MCI offers a similar service domestically, but uses the Session Initiation Protocol standard, which is believed to be the superior of the two technologies. As new VoIP applications emerge they will be based on SIP, not H.323, Kerravala says.
AT&T says it is using SIP signaling in the core of its network and will be able to upgrade to SIP-compliant devices and applications when the technology is more mature.
AT&T would not provide pricing or service-level agreement (SLA) information for the VoIP offering, saying it is "too premature," considering the service might not rollout until June.
Besides cost, Kerravala advises customers to look at standard SLA items such as latency, packet loss and jitter.
AT&T says it will include MOS measurements on its Business Direct Web Portal, where customers can monitor performance on their VPN. It also says it will provide standard latency, packet-loss and jitter-performance information for customer's voice traffic.
The carrier says it will offer its Enhanced VPN VoIP users a flat rate for domestic calling and users should expect to pay 3 cents or less per minute for off-net international calls.