Cisco routers get voice over IP: Module for 3600 series routers leads commercial deployment

Cisco Systems last week introduced a voice-over-Internet protocol module for its 3600 line of routers.

The module lets network users with 3600 series routers quickly and easily add voice-over-IP capability by adding the module and an upgrade to Cisco's IOS software package. Cisco expects that customers who use a mix of wide area network technologies, including frame relay, leased lines and ISDN, as well as those who want to extend voice capability to desktop applications, will benefit most from the upgrade.

The primary benefit is toll bypass, or using voice over IP to circumvent the public network. Fax traffic can be handled in the same fashion. The module also serves as a PBX extension, offers H.323 interoperability for voice-enabled Web applications and enables voice gateways from the public network to intranet and Internet gateways. The module is designed to work with existing telephones, fax machines, key systems and PBXs.

The new module enhances Cisco's voice-over-data offerings, which already include voice over asynchronous transfer mode and voice over frame relay, said Ian Pennell, marketing director for Cisco's Network to User Business Unit.

The module's performance depends heavily on network configuration, he said. To that end, resource reservation protocol, weighted fair queuing, IP precedence, compressed real-time transport protocol and multilink fragmentation and interleaving are included in the software upgrade. Each plays a role in ensuring that data and voice traffic coexist without huge gaps in voice transmissions or data logjams because of heavy voice traffic.

"These are knobs that allow you to fine-tune the network," Pennell said.

Cisco isn't first to market with voice over IP.

Smaller entrepreneurial companies have dominated the space, but Cisco's huge installed base may make others' product development leads irrelevant, said Tom Jenkins, broadband analyst for TeleChoice.

And while the 3600 module is a small office application that maxes out at 12 ports, Cisco plans to introduce a carrier-oriented, 60-port application in early 1998, Pennell said.

"The alternatives [for users with Cisco equipment in place] are to install a whole new piece of equipment [for voice over IP] or go with a card to put into an existing chassis," Jenkins said.