Polycom V2IU 4350 user manual Optionally enable priority IP addresses, Enable CAC

User Manual V2IU 4350 Converged Network Appliance

3.Specify the upstream and downstream bandwidth of your WAN link

4.Enter the WAN Downstream Bandwidth in Kbps.

5.Enter the WAN Upstream Bandwidth in Kbps.

Note	For FT1/T1/E1 links the upstream and downstream bandwidths will always be the
	same value (the link is full-duplex).

Optionally enable priority IP addresses

VoIP traffic from devices that use the VoIP ALG function (phones, video stations, softphones on Pcs, etc.) are already marked as high priority and do not need to be manually configured in this list. This list is used to prioritize voice traffic from trunk interfaces of IP PBXs or other high priority devices that do not use the VoIP ALG function of the 4350.

>>Enter the IP address of other high priority devices in the priority IP Addresses box.

You can enter individual IP addresses or a range using by appending a “-“character to the last octet. For example, 10.10.10.2-5 would specify 10.10.10.2, 10.10.10.3, 10.10.10.4 and 10.10.10.5 as voice devices.

Warning Care must be taken to ensure that the IP addresses entered do not include data devices such as PCs or workstations. Traffic from these devices will be placed in the priority voice queue internal to the 4350 and burst up to full line rate. This will starve actual voice devices by consuming priority bandwidth and result in dropped calls, busy signals & poor voice quality.

Enable CAC

The 4350 uses CAC to limit the number of active voice calls over the WAN link. This is necessary because a typical installation uses a ratio of 1:2 or 1:4 active voice calls to voice devices on the assumption that 50% or 25% of all users are on the phone at the same time. These ratios are guidelines only and at times the number of concurrent calls may exceed the amount of WAN bandwidth available to process the calls. In this instance existing phone calls will experience poor quality or be dropped all together. To prevent this from occurring a typical voice installation will set a threshold for the maximum number of concurrent voice calls supported by the WAN access link. New call requests in excess of this threshold will receive the equivalent of a “fast busy” and the WAN link will not become oversubscribed.

For IP Centrex installations the maximum number of concurrent voice calls is usually configured in the 4350 by enabling CAC. When the 4350 is deployed in IP PBX applications the maximum number of concurrent calls could be configured in the IP PBX. If the PBX is responsible for this setting you do not need to configure CAC in the 4350. Please check with your IT administrator to determine if this is the case.

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