Engineering a VoIP swap

Call it a neck-saving move.

Manufacturing firm Encorp Inc. recently swapped its aging, overworked 3Com Corp. IP PBX for Alcatel SA’s OmniPCX4400 IP PBX. With the 100-user NBX phone system pushed to its limits, Encorp IT director Stan Seago says: “We were overloading the system. Once we started getting to a saturation point, voice calls started digitizing and you’d lose parts of words.”

As a result, “a couple of vice-presidents were no longer getting through to our venture capitalists and key customers – so my neck was on the line,” he says.

The company, which makes equipment for managing electrical energy, recently made a switch from one LAN telephony system to another, opting to upgrade with Alcatel’s OmniPCX4400 IP PBX when it outgrew the 3Com NBX 100 system it installed more than two years ago.

Seago says the reason for the voice-over-IP swap “was a bit of future planning,” as the company saw its employees jump from 18 to 145 in two years. “We expect to continue growing,” he says.

The competition

Seago looked at Alcatel’s low-end OmniPCX 4400, which can scale to about 500 users. 3Com has since released its SuperStack 3 NBX, which scales to 700 users – and this week, an updated version that goes to 1,500 phones. But at the time, Seago choose Alcatel’s product because the 500-user NBX was new, and Alcatel already had support for larger users.

“When putting a phone in for the president of the company, you don’t want to put something in that was first-generation,” Seago says of the newer version of the 3Com product. However, if the decision was to be made today with the 3Com SuperStack NBX being out for some time, “I might have chosen differently,” he adds.

Other factors led to the decision to go with Alcatel, Seago says.

“With Alcatel, the pieces we wanted, like scalability, an integrated call center and multiple site support with directory services were all there,” he says.

Seago says he will use the OmniPCX to control call routing and queuing for the company call center, and for computer-telephony integration for call center staff. And because the box supports Lightweight Directory Access Protocol, he will integrate the phone system directory in with his Microsoft Active Directory to consolidate management for voice and data.

Although the OmniPCX offers more scalability and features, Seago says he misses the simplicity of the 3Com management interface.

“The 3Com box was easier to program,” he says. “The Alcatel [IP PBX] is a fairly complicated box. It has interfaces that let you do anything you want to do, including things you don’t want to do.”

Like any new system, there is a learning curve, Seago says. Recently while configuring two phones to cover the same extension, he and his staff inadvertently disabled both phones, he says.

Sticker shock

The difference in cost of the two companies’ IP phones also was a bit of a shock, Seago adds.

“What surprised me on the purchase was the high price for the phones themselves,” Seago says. “Our 3Com phones were costing us about US$220 each, but Alcatel’s Reflex [IP handsets] are costing us about $600 to $700, including all the software licensing.”

Once the Alcatel system was delivered and brought up, changes to the network in swapping 3Com IP telephony for Alcatel were almost nil, Seago says, as his data network already consisted of Alcatel OmniCore and OmniStack switches. Support for 802.1Q virtual LAN (VLAN) tagging on the OmniPCX and Alcatel Ethernet switches also has given the voice network a quality boost.

“With 3Com, voice was in direct contention with our data network,” because the 2.5-year-old NBX model didn’t support 802.1Q VLANs, Seago says. “If a big e-mail of FTP was going through the network, everyone in the company knew it.”

Now Seago segregates traffic going between the IP phones and the IP PBX into their own VLAN without any traffic prioritization.

“We didn’t have to implement priority queues on the switches and use prioritization because the isolation [of the voice packets onto a VLAN] has been able to take care of the entire load,” he says.

Seago also has extended the OmniPCX to a branch office in New Jersey, which is connected by a VPN link. A T-1 line from Qwest Communications International Inc. connects Encorp’s Windsor headquarters to the Internet, and a 256K bit/sec leased line links the New Jersey office at the other end. The company uses SonicWall VPN gateway/firewall boxes at each end of the network for IP Security traffic encryption. While no quality of service is used over the VoIP/VPN link, Seago says it’s enough to support the small branch office.

“We found that you can do three full conversations and have no corruption,” over the VPN line, even with data packets running alongside voice, Seago says. “If you do a large file transfer, yes, you’ll see a little [breakup] of voice, but in real-world mode, we haven’t seen it.”