Debate highlights VoIP hopes and fears

As vendors at the Voice on the Net conference pushed new applications for making IP telephony ubiquitous and more multimedia-friendly, attendees cautioned that plenty of basic issues still need to be resolved.

Those issuing warnings at the convergence industry’s annual gathering weren’t discounting the notion that Session Initiation Protocol (SIP)-based presence applications hold promise for connecting workers anywhere via video, voice and instant messaging. They are more concerned about how to secure IP PBXs from viruses, the shortage of enterprise voice-over-IP (VoIP) management tools and the complexities of rolling out converged applications beyond simple dial tone and calling features.

“SIP and presence are more of a high-talk item than something that’s actually being implemented,” said Dustin Goodwin, a network engineer with the New York integration firm, which offers IP PBX and VoIP network planning and installation services.

Security issues can complicate the rollout of SIP-based conferencing and any other applications that include IP voice. While users might think of voice as just another IP application, “worms and viruses change all that,” Goodwin said.

Many companies he has worked with have deployed IP PBXs and phones on secured VPNs, and even behind internal firewalls on the LAN, to avoid having a virus or other intruder bring down the phone system.

This is the practice at Florida International University, where Cisco Systems Inc.’s CallManager IP PBX and IP phones are deployed on a secured virtual LAN separate from other public servers.

“Voice is really separated from data by VLANs and other network controls, so we think it’s pretty secure,” said Al Losada, director of telecommunications at the Miami school. “But the challenge with this kind of architecture is that it’s difficult to roll out applications that integrate voice and IP PBX functionality.”

An example of this is a call-centre application Losada wants to install that would require PCs and IP phones to interact with the IP PBX. To do so, he would have to let PCs on the network see the IP PBX, which could leave the phone system at the mercy of a virus-infected PC.

Others at VON said the complexity of VoIP tempered their enthusiasm for the newfangled applications on display.

“It still takes a lot longer than it should to set up new users,” despite the promise of easier administration in a converged IP network, said Tom Stephens, network group leader at Cray Inc., the Seattle supercomputer manufacturer. The Cisco CallManager-based network installed several years ago at Cray runs smoothly, though he said “there’s more fulfilling work my staff could be doing than setting up IP phones.” He also said that more troubleshooting tools made specifically for VoIP networks are needed.

Vendors Avaya Inc., Cisco, GoBeam Inc., M5 Networks Inc. and Nortel Networks Corp. got a chance to harangue each other about shortcomings in each others’ VoIP products during an IP PBX Shootout debate hosted by Network World (U.S.) Editor in Chief John Dix. Avaya and Nortel representatives took turns criticizing Cisco’s IP telephony products, specifically citing potential vulnerabilities in Cisco’s CallManager IP PBX, which is based on Windows and SQL Server.

Cisco Technical Marketing Manager Bill King questioned Nortel’s lack of major customers for its IP PBX products, and the delays and strategy shifts in its enterprise VoIP business. He also challenged Avaya’s recent statements in market-share gains, saying the vendor was muddling its PBX and IP voice business performance to paint a rosier VoIP picture for itself.

Accentuating the positive

All this is not to say that VON did not serve to highlight the promise of VoIP.

Dennis Baron, senior project director of information systems at the Massachusetts Institute of Technology (MIT), discussed how the university and several others are creating an inter-campus phone network as an alternative to the public switched telephone network (PSTN) using Internet 2 and SIP. The network, which is still in the construction phase, initially will link Georgetown University in Washington, D.C., with Harvard University and MIT in Cambridge, Mass., and Texas A&M University in College Station. Ultimately, the network would serve about 200 major institutions, Baron said.

“Right in the aftermath of 9/11, it was found that e-mail was the best way to communicate,” said Baron, recalling that damaged regional carrier networks and an overloaded national phone network made calling difficult. “Many [people at universities] also found that SIP phones were useful,” he added.

Based on this premise, the network will link universities via Internet 2 and Paetec Communications, a New York competitive local exchange carrier. During a regional PSTN failure, calls would be rerouted to SIP-based Broadsoft softswitches and media servers at the universities and switched over Paetec’s network, where PSTN calls could be terminated. Campus-to-campus calls could be made freely among universities over the SIP-based network.

Jeremy George, director of the advanced networking group at Yale University in New Haven, Conn., said he holds out great hope for SIP-based presence applications that involve voice, video and instant messaging. He says users of Wi-Fi-enabled devices, 3G phones and PDAs that communicate over IP will drive demand for presence applications.

“Presence is the technology that glues these things together,” he said. “It will let people know how, when and where other people can be communicated with.”