User's Manual

Call type Voice compression channel usage
IP device to non-IP device These calls require a voice compression channel for the
duration of the call. If no channel is available, busy indication
is returned to the caller.
IP device to IP device Call progress tones (for example dial tone, secondary dial
tone, etc) do not require voice compression channels with
the following exceptions:
• Short code confirmation, ARS camp on and account code
entry tones require a voice compression channel.
• Devices using G723 require a voice compression channel
for all tones except call waiting.
When a call is connected:
• If the IP devices use the same audio codec no voice
compression channel is used.
• If the devices use differing audio codecs, a voice
compression channel is required for each.
Non-IP device to non-IP
device
No voice compression channels are required.
Music on Hold This is provided from the B5800 Branch Gateway TDM bus
and therefore requires a voice compression channel when
played to an IP device.
Conference resources and IP
devices
Conferencing resources are managed by the conference
chip which is on the B5800 Branch Gateway TDM bus.
Therefore, a voice compression channel is required for each
IP device involved in a conference. This includes services
that use conference resources such as call listen, intrusion,
call recording and silent monitoring.
Page calls to IP dDevice B5800 Branch Gateway only uses G729a for page calls,
therefore only requiring one channel but also only
supporting pages to G729a capable devices.
Voicemail services and IP
devices
Calls to the B5800 Branch Gateway voicemail servers are
treated as data calls from the TDM bus. Therefore calls from
an IP device to voicemail require a voice compression
channel.
T38 fax calls In order to use T38 fax connection, B5800 Branch Gateway
performs fax tone detection if the analog extension
connected to the fax machine is set as “Standard
telephone.” If the fax machine does not include an attached
handset that is used to make/receive voice calls, then the
Equipment Classification of an analog extension connected
to the fax machine can be set to Fax Machine, which will
result in T38 fax connection without fax tone detection and
respective signaling renegotiation. Additionally, a new short
code feature, Dial Fax, is available.
Voice compression channels
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