User`s manual

SIP User's Manual 464 Document #: LTRT-83303
Mediant 1000 & Mediant 600
The device stops collecting digits (for ISDN-to-IP calls) when:
 The sending device transmits a ‘sending complete’ IE in the ISDN Setup or the
following INFO messages to signal that no more digits are going to be sent.
 The inter-digit timeout (configured by the parameter TimeBetweenDigits) expires. The
default for this timeout is 4 seconds.
 The maximum allowed number of digits (configured by the parameter MaxDigits) is
reached. The default is 30 digits.
 A match is found with the defined digit map (configured by the parameter,
DigitMapping).
Relevant parameters (described in ''PSTN Parameters'' on page 344):
 ISDNRxOverlap
 ISDNRxOverlap_x
 TimeBetweenDigits
 MaxDigits
 ISDNInCallsBehavior
 DigitMapping
9.4 Using ISDN NFAS
In regular T1 ISDN trunks, a single 64 kbps channel carries signaling for the other 23 B-
channels of that particular T1 trunk. This channel is called the D-channel and usually
resides on timeslot # 24.
The ISDN Non-Facility Associated Signaling (NFAS) feature enables use of a single D-
channel to control multiple PRI interfaces.
With NFAS it is possible to define a group of T1 trunks, called an NFAS group, in which a
single D-channel carries ISDN signaling messages for the entire group. The NFAS group’s
B-channels are used to carry traffic such as voice or data. The NFAS mechanism also
enables definition of a backup D-channel on a different T1 trunk, to be used if the primary
D-channel fails.
The NFAS group comprises several T1 trunks. Each T1 trunk is called an ‘NFAS member’.
The T1 trunk whose D-channel is used for signaling is called the ‘Primary NFAS Trunk’.
The T1 trunk whose D-channel is used for backup signaling is called the ‘Backup NFAS
Trunk’. The primary and backup trunks each carry 23 B-channels while all other NFAS
trunks each carry 24 B-channels.
The device supports multiple NFAS groups. Each group should contain different T1 trunks.
The NFAS group is identified by an NFAS GroupID number (possible values are 1, 2, 3 and
4). To assign a number of T1 trunks to the same NFAS group, use the ini file parameter
NFASGroupNumber_x = groupID (where x is the physical trunkID -- 0 to 3) or the Web
interfacer (refer to ''Configuring the Trunk Settings'' on page 96).
The parameter ‘DchConfig_x = Trunk_type’ defines the type of NFAS trunk. Trunk_type is
set to 0 for the primary trunk, to 1 for the backup trunk, and to 2 for an ordinary NFAS
trunk. ‘x’ depicts the physical trunkID (0 to 3). You can also use the Web interface (refer to
''Configuring the Trunk Settings'' on page 96).