Back to the future: Carriers turn to traditional voice equipment to build out new IP networks

The explosive growth of data traffic in this decade has spawned the realization that the future of networks lies in the ability to carry voice traffic as an adjunct to data's dominant presence.

It likely will be many years before data-first networks entirely replace the huge installed base of voice networks, but numerous companies are springing up with plans to deliver a full package of voice and data services over fiber networks using Internet protocol (IP) as the primary mode of delivery.

Can such networks deliver the same quality of service (QOS) and variety of features for voice customers that traditional voice networks can offer? Yes. But to deliver the full package of quality and features such carriers may have to wait for new equipment or turn to more traditional voice network equipment.

Qwest Communications, perhaps the most visible of the new carrier breed, is deploying routing and access equipment from Cisco Systems and Hughes Network Systems, but it also is deploying Northern Telecom's DMS-250, a circuit switch designed for traditional voice networks. Qwest is using Nortel equipment to deliver its OC-192 backbone, but the DMS-250s are crucial because of their capacity to provision enhanced voice services.

The combination of port density and features that the Nortel switch delivers aren't available in IP switching equipment today, explained Dana Filip, Qwest's network engineering vice president.

IP switching vendors aren't standing still, however. Ascend Communications, which offers solutions for frame relay, asynchronous transfer mode and IP delivery, is developing systems that will allow IP networks to achieve the switching capability of traditional voice networks. The solution uses Ascend's IP Navigator and maps the IP packets onto an ATM backbone.

"With a core ATM network, you have the tools to provide those kinds of services," said Peter Joy, Ascend's IP product marketing manager.

But the crucial element missing from data-switching equipment is SS7. Data network providers are using so-called SS7 gateways that allow some access to SS7 intelligence. Those gateways aren't yet delivering the features or density of circuit switches, but new solutions are being developed.

Bay Networks is introducing a new remote access concentrator that communicates with the SS7 network to deliver voice-class services to data calls (see figure).

The new access concentrator targets large service providers rather than Internet service providers, said Kieran Taylor, Bay's product marketing manager for the Internet Telecom Business Group. The setup will allow the ISPs and other data network operators to access the remote access concentrator in carriers' central offices-eliminating the cost of buying their own-and to get SS7 capability in the bargain. It's also beneficial for voice carriers trying to mesh data traffic into their networks.

Incumbent carriers and telcos want to incorporate data into their network, Taylor said.

GEMINI OPENS SOUTHERN CABLE Gemini Submarine Cable System Ltd., a joint venture between WorldCom and Cable & Wireless, has completed the southern leg of its trans-Atlantic fiber ring. Gemini South runs between Manasquan, N.J., and Porthcurno, U.K. The northern leg, which runs between Charlestown, R.I., and Oxwich Bay, U.K., is scheduled to go live in October. The completed ring will deliver 60 Gb/s.

LUCENT TAPS WESTELL FOR ADSL Lucent Technologies plans to add ADSL capability to its 5ESS-2000 switch in cooperation with Westell Technologies. The solution will use discrete multitone line coding with an ATM network interface. Lucent and Westell also will design ADSL solutions for Lucent's digital loop carrier product lines, specifically the SLC-Series 5 and SLC-2000, and have resale agreements for Westell's SuperVision product line.