Voice over IP is gaining popularity. If it's not in your budget yet, it won't be long until it is. So what can you do to prepare your existing network in the meantime?
First priority should be making your Local Area Network as efficient as possible. You can do this in several ways, but one of the most important of which is getting rid of unnecessary protocols. For example, Windows 2000 no longer requires NetBIOS for file and print traffic, so why run it? Most mainframes now support IP, so although it may require considerable effort, removing IPX, SNA, NetBIOS over TCP, and other protocols will result in more available bandwidth on the network, and more available memory and faster response times in the clients and servers. Both of these are critical to a successful VoIP implementation.
Once you have removed all these protocols, you may find that the level of broadcasts on your network doesn't justify small subnets anymore. Moving to larger, 'flat' networks will allow you to remove routers that are no longer needed. These routers are not only points of failure, but are frequently bottlenecks, and are usually a major source of delay. Performing such network simplification will mean your VoIP traffic is more reliable and has higher quality.
Also, everyone knows that QoS is a major requirement for VoIP, so why wait until the last minute to QoS-enable your network? Since the configuration of QoS and VoIP are both relatively complex tasks, you don't want to be doing them at the same time if you don't have to. Work the bugs out of your QoS configuration now, and your VoIP project will be less likely to encounter glitches when you start it.
And last, it's never too early to begin planning. Among the things you can do before you even pick a vendor are:
- Identify the types of traffic on your network and prioritize them (voice may not be the most important).
- Determine existing call-traffic statistics and predict future statistics, including cost, average simultaneous calls, average duration, and source/destination pairs.
- Determine your dial plan.
- Prepare your network management system for VoIP, including upgrading your RMON probe and protocol analyzers to recognize and decode VoIP.
Thomas Alexander Lancaster IV is a consultant and author with over ten years experience in the networking industry, focused on Internet infrastructure.