Mitel 3300 ICP Hardware User's Manual page 44

3300 ICP Hardware User Guide
When controllers are networked together the compression becomes more complex.
The following examples are assuming that the IP devices are in different compression zones.
The WAN link is assumed to be G.729 compressed. The LAN link is assumed to be in the same
compression zone and running G.711.
An IP device on one system connecting to an IP device on a different system across a WAN
link (IP trunking) does not require a compression license as the conversion done on the DSP
resources in the IP phones.
An IP device on one system connecting to a TDM device on a different system across a WAN
link (IP trunking) will consume one compression licence from the system that the TDM device
is connected to.
A TDM device on one system connecting to a TDM device on a different system using IP
trunking will consume one compression license on each of the systems.
Conference/ACD Silent Monitor and compression licences
Conference calls require system DSP resources for E2T compression.
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