AudioCodes Mediant 800 - Call Termination before Call Establishment; Ring Detection Timeout; Remote PBX Extension between FXO and FXS Devices

CHAPTER29 Analog Gateway
Mediant 800 Gateway & E-SBC | User's Manual
This method operates correctly only if silence suppression is not used.
■ Protocol-based termination of the call from the IP side
Note: The implemented disconnect method must be supported by the CO or PBX.
Call Termination before Call Establishment
The device supports the following call termination methods before a call is established:
■ Call termination upon receipt of SIP error response (in Automatic Dialing mode): By
default, when the FXO device operates in Automatic Dialing mode, there is no method to
inform the PBX if a Tel-to-IP call has failed (SIP error response - 4xx, 5xx or 6xx - is received).
The reason is that the FXO device does not seize the line until a SIP 200 OK response is
received. Use the FXOAutoDialPlayBusyTone parameter to allow the device to play a busy /
reorder tone to the PSTN line if a SIP error response is received. The FXO device seizes the
line (off-hook) for the duration defined by the TimeForReorderTone parameter. After playing the
tone, the line is released (on-hook).
■ Call termination after caller (PBX) on-hooks phone (Ring Detection Timeout feature):
This method operates in one of the following manners:
● Automatic Dialing is enabled: if the remote IP party doesn't answer the call and the
ringing signal (from the PBX) stops for a user-defined time (configured by the parameter
FXOBetweenRingTime), the FXO device releases the IP call.
● No automatic dialing and Caller ID is enabled: the device seizes the line after
detection of the second ring signal (allowing detection of caller ID sent between the first
and the second rings). If the second ring signal is not received within this timeout, the
device doesn't initiate a call to IP.
Ring Detection Timeout
The operation of Ring Detection Timeout depends on the following:
■ Automatic dialing is disabled and Caller ID is enabled: if the second ring signal is not
received for a user-defined time (using the parameter FXOBetweenRingTime), the FXO device
doesn’t initiate a call to the IP.
■ Automatic dialing is enabled: if the remote party doesn't answer the call and the ringing
signal stops for a user-defined time (using the parameter FXOBetweenRingTime), the FXO
device releases the IP call.
Ring Detection Timeout supports full ring cycle of ring on and ring off (from ring start to ring start).
Remote PBX Extension between FXO and FXS Devices
Remote PBX extension offers a company the capability of extending the "power" of its local PBX
by allowing remote phones (remote offices) to connect to the company's PBX over the IP network
(instead of via PSTN). This is as if the remote office is located in the head office (where the PBX is
installed). PBX extensions are connected through FXO ports to the IP network, instead of being
connected to individual telephone stations. At the remote office, FXS units connect analog phones
to the same IP network. To produce full transparency, each FXO port is mapped to an FXS port
(i.e., one-to-one mapping). This allows individual extensions to be extended to remote locations. To
call a remote office worker, a PBX user or a PSTN caller simply dials the PBX extension that is
mapped to the remote FXS port.
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