User manual

DEFINITY Enterprise Communications Server Release 6
Maintenance for R6vs/si
555-230-127
Issue 1
August 1997
Maintenance Object Repair Procedures
Page 10-745ISDN-TRK (DS1 ISDN Trunk)
10
ISDN-TRK (DS1 ISDN Trunk)
A DS1 ISDN Trunk is known as a B-channel. It is a 64 kbps Bearer channel that
can be used to transmit digital traffic, be it voice or data. These trunks use a
separate channel for signaling (for example, for call setup); this mode of
operation is known as out-of-band signaling, as opposed to in-band, robbed-bit
signaling, where the signaling traffic flows over the same channel as the voice or
data traffic. The separate signaling channel is called a D-channel in ISDN
terminology, and it carries all the call control signaling messages for the DS1
ISDN Trunk B-channels. The D-channel for these B-channels is an ISDN-PRI
(Primary Rate Interface) Signaling Link Port (ISDN-LNK/ISDN-PLK).
On 24-channel interfaces, any of the first 23 ports on the DS1/UDS1 interface
circuit pack can be a B-channel. The 24th port may be used as a B-channel or as
a D-channel depending on the type of ISDN-PRI Signaling Group (ISDN-SGR) to
which it belongs. On 32 channel interfaces, any of ports 1-15 and 17-31 on the
DS1 interface circuit pack can be a B-channel. The 16th port may be used as a
B-channel or as a D-channel depending on the type of ISDN-PRI Signaling
Group (ISDN-SGR) to which it belongs. For more details, refer to the ISDN-SGR
and DS1-BD/UDS1-BD Maintenance documentation.
NOTE:
If a Packet Control circuit pack is used instead of a Processor Interface Link
as the interface of the PBX SPE to the D-channel, then the signaling link
port on the UDS1 circuit pack is referred to as ISDN-PLK and only the
TN464C or later may be used to carry D-channel Signaling. The B-channels
may be carried by any DS1/UDS1 interface circuit pack. If a Processor
Interface is used for connectivity then the Signaling Link port is referred to
as a ISDN-LNK and the TN767 or TN464B or later DS1 interface circuit
pack may be used to carry D-channels Signaling.
For interfaces using country protocol 1 on the DS1 Circuit Pack administration
form (including US), the signaling protocol used for the maintenance of the
B-channel is defined by the AT&T ISDN-PRI Specification.
1. For additional repair information, refer to the ‘‘DS1-BD (DS1 Interface Circuit Pack)’’
maintenance object.
2. A MAJOR alarm on a trunk indicates that alarms on these trunks are not downgraded by the
set options command and that at least 75 percent of the trunks in this trunk group are
alarmed.
MO Name (in
Alarm Log) Alarm Level Initial Command to Run Full Name of MO
ISDN-TRK
1
MAJOR
2
test port PCSSpp l DS1 ISDN Trunk
ISDN-TRK MINOR test port PCSSpp l DS1 ISDN Trunk
ISDN-TRK WARNING test port PCSSpp sh DS1 ISDN Trunk