AT&T DS1/DMi/ISDN-PRI manual NFAS-PRI Only, Procedure 262 Word 2 ISDN-PRI D-Channel Backup

ADMINISTRATION OPTIONS AND REQUIREMENTS — GENERIC 2 7-67

Field 9

Field 10

The field accepts encodes from 0 through 255, which correspond to 1 second intervals for a maximum elapsed time of 4 minutes and 15 seconds. The default value for this T203 timer is 30 (30 seconds). This timer functions to monitor the facility data link and specifies the maximum time allowed without frames being exchanged on a data link layer connection.

The field accepts encodes from 0 through 255, which correspond to 0.1 seconds per increment for a maximum range of 25.5 seconds. The default value for this T200 timer is 10 (1 second). This timer functions to monitor multiple frame operation on the data link layer.

Field 11	This field defines a value for the N200 counter. The value determines the maximum
	number of frame retransmissions. Permitted are 1 to 10, with 3 being the default
	value.
Field 12	This field defines a value for the K counter. The value determines the maximum
	number of outstanding or unacknowledged information I frames. Permitted values
	are 1 to 10, with 7 being the default value.

NOTE: Administration values for these procedure 262 timers and counters must be coordinated with the other terminating end.

Field 13 NFAS-PRI Only

Use to specify NFAS arrangements. This information must match exactly and the encode must come from the premise switch (as described in Technical Publication

41459). Field encodes and their descriptions are:

●Dash (–),the only value for non-NFAS arrangements

●Any number within the range of (0 through 31) for NFAS arrangements.

Procedure 262 Word 2: ISDN-PRI D-Channel Backup

This procedure is currently only applicable for certain ISDN-PRI connections. Specifically, those B- channel groups that use NFAS. Each of these groups is identified by a unique number known as the D-Channel group number. For NFAS, fields 2 through 5 define the D-channel for a signaling group. Figure 7-30,Procedure 262 Word 2: ISDN-PRID-Channel Backup (Generic 2), depicts this procedure.