Contents

Communication

Use this page to define a set of Codec communications for the endpoints (lines, stations, and servers). Communication between devices require a mapping between locations.

Click Modify to display the list of prioritized Codecs. Select the Codecs to map to the endpoints. By default, no Codecs are selected. You must select one Codec for the mapping to be valid. The Up and Down buttons set the preferred order of Codecs to use.

Click Set Parameters to modify the Frame Size (in milliseconds) and the Frames per Packet of a Codec. This option is available only for G.711 Codecs.

Us the up and down arrows to set the Inter-conference latency in milliseconds. You assign latency values to connections between locations. By specifying the latency values, you create a method of indicating which connections CIC should prefer when it joins regional conference calls through hub servers.

By default, the latency value for communications within a location is 10. The default latency value for communications to other locations is 100. Acceptable latency values range from -1 to 3000. You can adjust the latency values to specify which location Interaction Center should first attempt to use in establishing connections between regional servers and hub servers.

As an example, if the cost of bandwidth usage to one location is much more expensive than another location, you could give a higher latency value to the first location. Interaction Center would try to join conference calls through a hub server in the second location. Only if no hub servers in the second location had enough resources to facilitate the conference calls would Interaction Center then try to use a hub server in the first location.

You can use any criteria you prefer to determine the latency values that you will assign to connections between locations. The criteria could include bandwidth costs, bandwidth limits, network quality, and so on.

Notes

Latency: For distributed conference calls in the Interaction Center environment, latency does not implicitly refer to the delay in the relaying of transmissions on a network. Instead, latency is a value that an administrator specifies to indicate which locations Interaction Center should first use to find a hub server for joining regional conference calls together.

Multiple Codecs: To enable the use of multiple codecs, contact your PureConnect Customer Care support representative.

No Codecs Defined: If two devices each have a Codec defined, but there are no Codecs defined in the communications between them, then they are not allowed to communicate directly to each other. This can be used to intentionally block traffic between some Codecs.

G.726: G.726 is only available with AudioCodes.

Packet and Frame size: Summary on packet size and frequency from the www.erlang.com website: "The frequency at which the voice packets are transmitted have a significant bearing on the bandwidth required. The selection of the packet duration (and therefore the packet frequency) is a compromise between bandwidth and quality. Lower durations require more bandwidth. However, if the duration is increased, the delay of the system increases, and it becomes more susceptible to packet loss; 20ms is a typical figure." So, the more of the voice you put in a single packet (i.e., 60ms versus 20ms), the more of the voice you lose if that packet is lost.

MOS: The quality of transmitted speech is a subjective response of the listener. A common benchmark used to determine the quality of sound produced by specific Codecs is the mean opinion score (MOS). With MOS, a wide range of listeners judge the quality of a voice sample (corresponding to a particular Codec) on a scale of 1 (bad) to 5 (excellent). The scores are averaged to provide the MOS for that sample.

Tip: For the most current list of Codecs, see the latest version of SIP Application Note on the Product Information site.