AudioCodes Mediant 800 MSBG - Configuring Internal Clock as Clock Source

SIP User's Manual 638 Document #: LTRT-12804
Mediant 800 MSBG
10.1.2 Configuring Internal Clock as Clock Source
This section describes how to configure the device to use its internal clock source. The
internal clock source is a stratum 4E-compliant clock source. When the device has no line
interfaces, the device should be configured in this mode.
 Set the clock source to be from the internal oscillator device:
TDMBusClockSource = 1 (internal)
 Set the line to drive the clock on all trunks:
ClockMaster = 1 (for all trunks)
10.2 Release Reason Mapping
This section describes the available mapping mechanisms of SIP responses to Q.850
Release Causes and vice versa. The existing mapping of ISDN Release Causes to SIP
Responses is described in ''Fixed Mapping of ISDN Release Reason to SIP Response'' on
page 639 an
d ''Fixed Mapping of SIP Response to ISDN Release Reason'' on page 641.
To override this hard-coded mapping and flexibly map SIP responses to ISDN Release
Causes, use the ini file (CauseMapISDN2SIP and CauseMapSIP2ISDN, as described in
''ISDN and CAS Interworking Parameters'' on page 799)
or the Web interface (see
''Configuring Release Cause Mapping'' on page 162).
It is also possible to map the less com
monly used SIP responses to a single default ISDN
Release Cause. Use the parameter DefaultCauseMapISDN2IP (described in ''ISDN and
CAS Interworking Parameters'' on page 799) to
define a default ISDN Cause that is always
used except when the following Release Causes are received: Normal Call Clearing (16),
User Busy (17), No User Responding (18) or No Answer from User (19). This mechanism
is only available for Tel-to-IP calls.
10.2.1 Reason Header
The device supports the Reason header according to RFC 3326. The Reason header
conveys information describing the disconnection cause of a call:
 Sending Reason header: If a call is disconnected from the Tel side (ISDN), the
Reason header is set to the received Q.850 cause in the appropriate message
(BYE/CANCEL/final failure response) and sent to the SIP side. If the call is
disconnected because of a SIP reason, the Reason header is set to the appropriate
SIP response.
 Receiving Reason header: If a call is disconnected from the IP side and the SIP
message includes the Reason header, it is sent to the Tel side according to the
following logic:
• If the Reason header includes a Q.850 cause, it is sent as is.
• If the Reason header includes a SIP response:
♦ If the message is a final response, the response status code is translated to
Q.850 format and passed to ISDN.
♦ If the message isn’t a final response, it is translated to a Q.850 cause.
• When the Reason header is received twice (i.e., SIP Reason and Q.850), the
Q.850 takes precedence over the SIP reason and is sent to the Tel side.