Specifications

Bandwidth, Codecs and Compression
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Figure 27: IP Networking Compression Zones Example
Although the network shown in the figure above is not a real network, it highlights some of the
areas to consider in allocating bandwidth in different parts of the network:
• Calls within Zone 1 of both controllers are not compressed.
• Calls between controller A and controller B are sent over an IP networking route (IP trunk)
and are compressed but can be set up as non-compressed.
• All IP networking connections are considered as originating from Zone 1. If the IP network
connection is not compressed, but a call originates in a zone that normally uses compres-
sion and it goes back to Zone 1, the call is completed with compression.
• Although the two units are logically separated, they share a common physical infrastructure.
This is similar to network VLAN operation, but can lead to some unusual operations, similar
to VLAN, where local devices talk through a router. In effect, the controllers can be consid-
ered as voice routers.
• The IP phone in controller A, Zone 3 registers with controller A over the WAN link. Bandwidth
used by this device to talk to other devices on controller A is not counted against the IP
networking limits. Bandwidth for this remote phone should be considered in addition to the
IP networking requirements, since both IP network connections and remote connections
share a common infrastructure.
• If the phone in controller A, Zone 3 wants to communicate with the phone in controller B
Zone 1, it consumes an IP trunk session or channel, but no actual WAN bandwidth since
the two phones stream directly within the LAN. This call could also be blocked if there are
insufficient IP trunk sessions or channels allocated.
• A controller can have a maximum of 999 compression zones.
More details on zones and setup can be found in the Technician’s Handbook and the installation
documentation.