Connecting to Voice over IP Services

Internet Connection

A voice conversation requires a steady stream of data to arrive in the right order without excessive delays (latency) or time variations (jitter). Early VoIP services frequently used the Internet to carry calls and most of the time this works very well. However the Internet does not differentiate between voice packets, web page packets or any other data packet type. This can often result in a poor quality voice service when data packets crowd out voice packets. All CityLink network connections, such as PublicLAN, which are used for delivering Internet services provide symmetric bandwidth, (the same bandwidth in both send and receive directions), very low latency and minimal jitter, which is ideal for sending voice over the Internet. However this does not guarantee that the demands on bandwidth by other data types do not impact a voice call.

Dedicate Connection

The ideal way to have good quality VoIP calls is to ensure you have enough data capacity to carry VoIP calls, without any other data service impacting on this capacity. One way to ensure this does not happen is to purchase a dedicated connection for VoIP. CityLink's PublicLAN and PrivateLAN network connections can be used to provide dedicated connections between an office and a voice service provider.

Shared Connection with Quality of Service

When voice and data share the same IP connection, which is the preferred implementation method by some services provides, it is possible for data applications to affect the network capacity used for voice calls. In this case it is best practice to prioritise the voice packets using 'Quality of Service' or 'QoS' management tools. QoS management is usually a function of an edge router which is located in the customer premise.