| QoS Important for Voice Traffic |
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Voice traffic is the most vulnerable to the network flow quality because of it's nature.
Like any other Internet traffic, Voice Traffic quality is directly affected by two major factors:
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Lost packets
- Delayed packets
Packet loss causes voice clipping and skips.
Packet delay cause either voice quality degradation due to the end-to-end voice latency or even packet loss if the delay is variable.
If the end-to-end voice latency becomes too long (250 ms, for example), the conversation begins to sound like two parties talking on a walky-talky radio. If the delay is variable, there is a risk of jitter buffer overruns at the receiving end, handling drops and delays is even more critical when including fax and modem traffic over IP networks. If packets are lost during fax or modem transmissions, the modems are forced to "retrain" to synchronize again. By examining the causes of packet loss and delay, we can gain an understanding of why Quality of Service (QoS) is needed in all areas of providing VoIP across any network.
End-to-End Quality of Service
A service model, also called a level of service, describes a set of end-to-end QoS capabilities. End-to-end QoS is the ability of the network to deliver service required by specific network traffic from one end of the network to another.
The ability of a network to deliver service needed by a specific network applications from end-to end with some level of control over delay, loss, jitter, and/or bandwidth can be categorised into levels of service:
Recommendations
Why Asergis supplies dedicated Broadband connections for its VoIP service
Asergis uses dedicated Broadband connections for its VoIP service, for you to maximize the quality of any voice calls made, also having a dedicated connection reduces the risk of any voice calls degradation.
Using VoIP and data (Internet traffic) on the same connection
If you use voice and data (Internet traffic) on the same connection, you will need to use special hardware such as a QoS device, the device separates the voice and data; if not, some voice calls made will not be clear.
Deploying VoIP this way, you will need to do some additional network configuration, allowing you to be able to separate any voice calls from Internet traffic.
If you use a third party Broadband connection
Asergis has no control over other Broadband suppliers networks, some networks are VoIP friendly and others are not, so if issues develop, then Asergis may not be in position to resolve them.
Asergis can only fully trouble shoot any problems with the quality VoIP service, if the service is being used on the Asergis Broadband network and through to the point where the call is terminated e.g. (BT, Vodafone, O2 etc.)