Moving toward convergence

With the industry buzz about voice/data convergence getting louder all the time, you may soon find your phone system tied into your data network, with you centrally controlling the whole thing from your PC.

We looked at AltiGen Communications' AltiServ, a Windows NT-based telephone and voice mail system. AltiServ is a combination PBX, voice mail and messaging system housed in a single NT server. With the addition of AltiWare IP, telephone calls can be routed over an IP network to another AltiServ server.

While AltiServ Open Edition (OE) 2.1 has been on the market since late last year, we now think it warrants closer examination because it blends PBX, PC and messaging technologies into one system, and it costs anywhere from 30% to 75% less than traditional phone systems with similar feature sets.

AltiServ is extremely simple to set up and requires little ongoing management. End users can view and change their voice mail configurations using a Web browser.

Our tests show this product is well-suited for companies with several branch offices, but some of the standing hardware limitations affect its overall scalability. Currently, AltiServ is limited to 144 users per server because the system uses ISA slots for the PBX/voice mail functionality and PCI slots for voice over IP.

We first tested AltiServ with voice traffic only. Our users reported the system was easy to use, and their voices were clear and easily recognizable.

Next, using a packet generator we placed a moderate network load across our pseudo-WAN link. Conversation quality degraded noticeably. Users said it sounded like they had a terrible cellular phone connection.

We thought the problem was a traffic issue across the WAN link rather than a problem with AltiServ, so we configured the routers to use Priority Queuing (packet prioritization) for the voice-over-IP packets. Sure enough, voice quality returned to its previous level.

In the version of AltiWare IP we tested, the bandwidth requirements for voice over IP were surprisingly large compared to competitors' voice-over-IP products. AltiWare IP requires 96K bytes per channel whereas other voice-over-IP products that support compression require only 10K to 20K bytes per channel.

AltiGen is expected to release a new version of AltiWare IP this fall that will support compression.

Because users are accustomed to 24-7 telephone uptime, we also tested AltiServ's power failure transfer feature, which lets designated telephone extensions remain open in case of an interruption in electrical power.

We simulated a power outage in Office A. A UPS attached to the server -- which must be purchased separately -- kicked in, and users noticed nothing.

Next we simulated a complete power failure in Office B. Calls were dropped and messages being left were incomplete. However, all incoming calls were routed to the designated extensions in that office segment. Outbound calls could only be placed from the same extensions. All other phones were dead, and all messaging features were unavailable. Once power was restored and the server finished rebooting, everything functioned as if nothing happened.

Neither AltiGen nor its resellers recommend the added expense of error checking and correcting memory or RAID for high availability. AltiServ only taps the hard disk when a message is being left, so an AltiServ box is generally less stressed than even a departmental NT file server, they say.

The management of an AltiServ phone system is divided into three parts. Installation and configuration are handled by an administrator. End users employ a Web browser to maintain their own mailbox settings. Using an optional add-on called AltiConsole, a live operator can manage the flow of incoming and outgoing telephone calls.

At all levels, AltiGen has done an outstanding job of making menus simple, easy to understand and intuitive. Hardware installation was easy, and installing the software took less than 15 minutes. We accepted all the defaults.

To activate individual extensions, all you have to do is plug a telephone into the system and pick up the receiver.

The Web-based tool used for voice mail access is called AltiReach. It lets users view messages and make changes to mailbox settings from anywhere, as long as they can connect to the AltiGen server, through a dial-up connection or through the Internet.

Over the past decade, telephone systems, like computer systems, have become smaller, more powerful and less expensive. With AltiServ, AltiGen is making it easier to contemplate blending your phone service with your data network.

This story, "Moving toward convergence" was originally published by Network World.

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