Figure 1.5 A Traditional Phone Call
Unified Communications ??? Chapter 1 9
So, what did this mean for voice communication? Well, basically, it meant we could do
more with less. By that, I mean that by leveraging this method of distributing our transmission,
we no longer had to ensure that we had a 1:1 ratio of potential phone calls to phone lines.
On the internal cabling front (from the wiring closet to the desk), it also meant that we no
longer had to have cable runs for both data and voice. However, adding voice onto our
existing data infrastructure was not quite that simple. We needed to address a number of
items, possibly the most important of which is the quality of the call being transmitted.
Quality of Service
Taking what we??™ve said regarding packet switching, logic would tell us that conversations
would be broken up into various chunks, arriving out of order. So, if Alexander Graham Bell
were alive today, a conversation over VoIP would have come across something like ???to see
Mr. Wat??”son here??”I you. come want??? instead of ???Mr. Watson??”come here??”I want to see you.???
Right? Wrong.
Early on, the early developers of VoIP were quick to grasp the idea that this wouldn??™t
work. Likewise, they were quick on the ball to determine that if a voice call over IP didn??™t
sound almost exactly the same as an analog call, it would never work. Therefore, they made a
variety of ???tweaks,??? including adding ???comfort noise??? to the call, and other things to reduce
unwanted problems such as ???jitter.
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