Voice quality is a major concern for organizations investing in a VoIP phone system or upgrading voice networks to IP. There are several factors that can affect the quality of a voice call, also known as Quality of Service. Engineered properly, an IP based phone system / network can provide the same quality as a traditional PBX using the PSTN network. The issues listed below will be discussed in further detail in future posts to the Inphonite Blog.
Bandwidth. The first and most important requirement is having sufficient bandwidth available. Typically, networks are over-engineered to ensure voice quality. However, throwing bandwidth at the situation is not always the best nor the most cost effective solution.
Latency or Delay. There are many solutions on the market that will measure and detect delay. Possible causes of latency include IP based premise equipment, the network, or Internet connectivity.
Jitter. When a network is congested, packets can arrive at their destination early, late, or out of sequence. Buffers can compensate for jitter by collecting the packets, storing them for a brief period, and then sending them on to their destination at regular intervals. The jitter buffer is located at the receiving end of the network, and is often included in the hardware/equipment. (Question: Is it included in a phone, or the phone system?)
Packet Loss. In a data network, packet loss can result in a misspelled word, but packet loss on a voice call is considered more serious by users as it results in garbled conversations. Packets can get lost because of collisions on the LAN, a high traffic network, and generally, insufficient bandwidth.
Before installing a VoIP phone system or upgrading a voice network to IP, be sure to conduct a Network Assessment. Usually the service provider of the VoIP lines will provide this assessment. They may also offer ongoing management services to proactively detect and resolve issues before they become critical.
David Clarke
Business Development Manager
PIKA Technologies Inc.
www.pikatechnologies.com