ISDN-TRK (DS1 ISDN Trunk)

ISDN-TRK (DS1 ISDN Trunk)

Table 42. ISDN-TRK (DS1 ISDN Trunk)

MO Name (in Alarm Log)

Alarm Level

Initial Command to Run*

Full Name of MO

ISDN-TRK**

MAJOR*

test port GGGVSpp l

DS1 ISDN Trunk

ISDN-TRK

MINOR

test port GGGVSpp l

DS1 ISDN Trunk

ISDN-TRK

WARNING

test port GGGVSpp l

DS1 ISDN Trunk

Note: For Avaya G700 Media Gateway systems you must consult local records for the location and designation of the equipment rack where the G700 is mounted.

*For additional repair information, see also DS1-BD for TN767 ports and MM710.

A MAJOR alarm on a trunk indicates that alarms on these trunks are not downgraded by the set options** command.

Table 42. ISDN-TRK (DS1 ISDN Trunk)
MO Name (in Alarm Log)	Alarm Level	Initial Command to Run*	Full Name of MO
ISDN-TRK**	MAJOR*	test port GGGVSpp l	DS1 ISDN Trunk
ISDN-TRK	MINOR	test port GGGVSpp l	DS1 ISDN Trunk
ISDN-TRK	WARNING	test port GGGVSpp l	DS1 ISDN Trunk
Note: For Avaya G700 Media Gateway systems you must consult local records for the location and designation of the equipment rack where the G700 is mounted.
*For additional repair information, see also DS1-BD for TN767 ports and MM710.
A MAJOR alarm on a trunk indicates that alarms on these trunks are not downgraded by the set options** command.


Note:	Many trunk problems are caused by incorrect settings of parameters on the trunk group administration form. Settings must be compatible with the local environment and with parameter settings on the far-end. See Administrator's Guide for Avaya MultiVantage Software, 555-233-506, for the correct settings for administrable timers and other parameters on a country-by-country basis.


Note:	Throughout this section, the term DS1 refers to the MM710 Media Module.

A DS1 ISDN trunk is a 64 Kbps bearer channel used to transmit digitized voice or data traffic. These trunks, or B-channels, use a separate channel, the D-channel for call-control signaling. This mode of operation is known as out-of-band signaling, as opposed to in-band robbed-bit signaling, in which signaling is carried in the same channel as the voice or data traffic. One D-channel, or ISDN signaling link (ISDN-LNK), carries signaling messages for several B-channels, forming an ISDN signaling group (ISDN-SGR).

A B-channel may be a port on a MM710 series DS1 Media Module.

Two types of DS1 interfaces exist:

24 DS0 channels on a 1.544 Mbps link
31 DS0 channels + 1 framing channel on a 2.048 Mbps link

On 24-channel interfaces, any of the first 23 ports on the DS1 Media Modules can be a B-channel. On the MM710, the 24th port may be used as a B-channel or as a D-channel depending on the type of ISDN-PRI signaling group (FAS or NFAS) implemented on the Media Module. For more details, refer to ISDN -SGR. The signaling for these B-channels is done over a D-channel located on a MM710.

On 32 channel interfaces, any of ports 1-15 and 17-31 on the DS1 interface Media Module 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 (FAS or NFAS) to which it belongs. For more details, refer to ISDN-SGR and "DS1-MM (DS1 Interface Media Module)" in this chapter.

For interfaces using country protocol 1 on the DS1 Media Module administration form (including US), the signaling protocol used for the maintenance of the B-channel is defined by the ISDN-PRI specification. For interfaces using country protocols other than 1, the signaling protocol used for the maintenance of the B-channel is defined by the CCITT ISDN-PRI Specification.

There are five possible service states for a B-channel. the service state is negotiated with the far-end switch, changes over time, and may have a far-end and near-end components. The service state is initialized to out-of-service/Far-End and an attempt is made to negotiate it to in-service.

The ISDN-PRI Specification defines the possible SERVICE STATES for a B-channel. The service state is negotiated with the far-end switch, changes over time, and may have a far-end or near-end component. The service state is initialized to the Out-Of-Service/Far-End state and an attempt is made to negotiate it to In-Service.


Note:	The service state of a particular DS1 ISDN Trunk B-channel can be displayed by issuing the status trunk trunk group/trunk member system technician command.

When a call is present, the specification defines the permissible call states as well. There are tests in the short and long test sequences for DS1 ISDN Trunk designed to audit these states and ensure agreement between both ends of the PRI connection.