VoIP is coming to an enterprise near you; this learning curve is one you can't miss

Enterprise Networks & Servers, Jul 2005 by Patterson, Michael

Networking guys have traditionally given telecommunications technology and gear a wide berth. Our province was the local area networks (LANs), wide area networks (WANs) and wireless networks. Telecom typically wasn't even considered an IT function - an entirely different set of facilities staffers usually dealt with the intricacies of their world.

How things change. The maturation of Voice over IP (VoIP) signals a combining of both worlds. Gone is the need to run two completely separate infrastructures for voice and data. Of course, many companies have invested heavily in their old legacy voice networks. Those bulky PBX's (phone switches) and time division multiplexed (TDM) systems cost a bundle and won't be dispensed with until their useful life is over. But whether that point lies on the immediate or far horizon, networking personnel better become proficient about VoIP - and fast.

After all, VoIP is no longer being pushed by relative newcomers like Vonage, AltiGen, Vertical Networks and Shoreline Communications. In the past year or two, the giants of old school telecom have also embraced it such as Avaya, Nortel, Alcatel, Siemens and Mitel. And if Cisco and 3Com have already released a wealth of VoIP products, you can be sure that there is a big market for it.

What you need to know

VoIP makes voice an all digital process. It has successfully leapt over the quality hurdle and now claims to offer similar quality to analog-based voice services. Standards such as H.323 by the International Telecommunications Union bring VoIP quality up to the level of older switched networks and open the door for its widespread adoption.

Maintaining the desired level of quality, though, is the job of networking staff. Therefore, VoIP has made the network even more critical to the enterprise. If the routing topology goes down even for a few seconds, for instance, the phone lines are down during that time. If someone makes a firewall change or implements a VLAN incorrectly on a switch, calls can be disconnected. So the network needs to be robust enough to handle the additional load and provide an adequate level of service. This means testing, modeling and, if necessary, building out the network so it can handle the traffic.

One vital element is constant trending of network traffic in order to help identify traffic growth. I'd recommend the use of freeware such as RRDtool (www.rrdtool. org) or Denika if you use What's Up by Ipswitch on your network (www.somix.com/products/denika.php).

Another key point is application testing. It isn't enough to run a few checks on the network or to add a little bandwidth. You need to know how your applications will respond as most of the problems experienced by companies with VoIP in production are related to applications. It is much easier, and far cheaper, to fix these problems in pre-deployment testing.

Additionally, watch out for patches and upgrades. It is essential to test the system before every upgrade. And if you apply patches monthly, be sure to discover how those changes might affect VoIP performance. The last thing you need is for one patch to take your whole system down.

Testing, therefore, is the key to successful VoIP deployments. Test before, during and after any VoIP project in order to take the uncertainty out of the $64,000 question - how much traffic can your network really handle without degrading voice quality? It is during testing that you isolate the configuration errors, interoperability issues and performance bottlenecks that can hamper voice performance.

The wise thing to do is roll out VoIP in a lab environment first. Check it out thoroughly in terms of compatibility and network readiness. Once you are satisfied, begin infrastructure rollout and then tackle applications. As another safeguard, perhaps you should begin first at a branch office before attempting a corporate-wide deployment. Work out the kinks at one branch, learn the ropes and then go wider.

Another roll-out caution is to leave operational TDM-based gear alone. If the system is working, why mess with it? You've already spent the money on it so why rip it out? Instead, wait for events such as support discontinuance, PBX break downs or even building renovations to consolidate voice and data into one network. That maximizes your ROI on old equipment and gives you a gradual roll out path for VoIP. Begin by replacing the existing telephony hardware and software including switches, PBXs, voice mail, answering system, etc. Next, the telephone handsets need to be VoIP enabled.

Back to school

If you don't know anything about VoIP and the prospect of dealing with it scares you, it might be wise to go back to school and learn the basics. It's pretty easy once you get the hang of it, but it is a new aspect of networking - one your had better become familiar with.

Unquestionably, VoIP is coming to an enterprise very near you. If you grasp it and add it to your networking repertoire, you will greatly enhance your value within IT. If you fail to come to terms with it, however, a few years from now, you could eventually find yourself out of a job.