Maximise your IP telephony

How to measure the sound quality of a ToIP conversation?

Telephony on IP is a good example of a demanding application on the quality and performances of the network. An important latency or jitter causes a poor sound quality, even impossibility to establish a conversation. Moreover, and unlike most traditional client-server applications, the conversations are established from beginning to end of the network, without necessarily transiting through a central point.

Use of IP/SLA with IP Telephony

In the case of IP telephony, the Cisco IP SLA technology is particularly interesting for 2 reasons: the measures taken from beginning to end of the network, and the production of specific indicators on the sound quality of the conversations. With the traditional monitoring tools (and centralized), when all flows are not centralized, it is not possible to know accurately the sound quality that for example a conversation between 2 WAN sites would have intervening.

The use of Cisco IP SLA technology makes it possible to have these measures at each point of the network. In the case of telephony, the jitter and latency network measures are very relevant information, bringing in particular to the quantified measurement of the sound quality. It is the sound quality that a phone conversation would have if it took place between 2 active devices (routers or switches), thanks to ICPIF and MOS score calculations.

Sound quality measured between 2 remote switches on a WAN IP/MPLS

Report stands as a collector of data IP SLA. By regularly recovering the measurements taken by the various compatible Cisco IP SLA equipment, it produces the reports and alerts that give you the vision on the service and performance quality of your ToIP infrastructure.