Once upon a network time things were simple. All you had to do was figure out who unplugged the coax cable from their t-connector, and plug it back in again. Problem solved, network back to normal, time for lunch. Then we got smarter and switched to 10Base-T which meant nobody could snaggle the network jut by unplugging something, unless it was the Ethernet hub - and no, they weren't switches back then. Of course we soon realised that this network was so useful it would be even more useful if we connected it to some other networks.
Companies such as Cisco became monster corporations almost overnight due to our fascination with connecting everything in our offices to everything else on the planet. They did, and still do, a passing good job at routing all that information to the right place, but we who use the networks refuse to stop finding new things to stuff into the pipes. If this was plumbing it would be akin to using the dunny to flush your garbage instead of hauling it to the kerbside bin. The engineers at your local council would soon pay a visit to explain the way things work if you tried that solution.
However, nobody stops us from jamming more packets down our pipes, or if they try, we just order a fatter pipe. That strategy hasn't always been the most elegant solution but it generally worked, and the falling price of broadband has made link boosting a popular and cheap network management tool. Now we've added voice to the binary morass clogging our network pipes in the form of VoIP and IP-based PBX systems. And suddenly, like a watermelon shoved in the water closet, things are starting to choke and gurgle.
Basically the problem with VoIP and other services of similar ilk is that they expect to operate in real-time while your network and the Internet weren't designed to operate quite so quickly, and even when they do manage a burst of real-time most were never designed to maintain this speed continuously. Although ordering fatter pipes can somewhat alleviate the problem, the different nature of traditional network data versus instant demand data makes it difficult to prevent the newcomer consuming all the extra bandwidth you just installed.
This makes the challenge of managing a converged network rather more complex than was once the case.
Tomorrow: SIP slurps time?