Voice Over Internet Protocol (VoIP)
Using the Internet to deliver voice information is not new, however significant advances have been made in the quality of the transmission available through this technology.
In the early days of telephony, human sampling was conducted to ensure the quality of voice traffic used to deliver toll calls. The model developed was Mean Operator Service Quality (MOSQ) wherein a panel of operators rated the voice quality from one (1) to five (5). To measure up to toll quality, the circuit(s) needed a MOSQ average of 4.0 . The carriers chosen by Telecompute to deliver VoIP are held to an even higher standard than circuit switched toll quality, a MOSQ of 4.5.
Although you should never experience these problems with VoIP provided by Telecompute, here are some of the problems that can detract from VoIP quality, if not managed properly:
Because VoIP is a real-time communication, it is very sensitive to delays in the network. Acceptable VoIP quality requires a delay of not more than 80ms in either direction for true toll quality voice communication. Many services may attempt to provide throughput for both voice and data, which requires a system for assigning priority as to which information gets on the network. Our voice traffic does not have to compete with data flows. Voice is all that we do.
Jitter causes irregularities in the flow and delivery of data. The tolerance range for VoIP jitter is in the range of 20-30ms. Jitter buffers and high quality routers temporarily store and 'smooth out' the delivery of voice packets.
Some VoIP vendors employ the Internet for delivery of their voice traffic. By it's very nature, that places those calls vying for resources on the public network on a 'best efforts' system for delivery. Although a packet loss of 1% is still compatible with toll quality voice traffic, a loss of as much as 3% can be disruptive. Compression techniques, applied to specific types of voice traffic can help. However, when the call reaches its final destination, anything less that 64k (+ overhead) - the voice standard employed over the public switched telephone network - would be undesireable. Our dedicated backbone ensures that nothing gets delayed or lost. Actual packet loss on our network has been measured at 0.001%. Delivering 0.99999 of the packets provides the much sought after 'five nines' of reliability that only the best can boast.
Page updated: 6/1/2006 8:21AM | Printer Friendly Version