2.0 Mb DTI/PRI Administration and Maintenance Guide Book ... - Home

Chapter 3 — DPNSS1/DASS2 features description and implementation Page 747 of 1536
If the originating party is a local set, treatment depends on the
customer-defined congestion treatment (either busy or overflow) or NARS
call blocking intercept treatment (either overflow, busy, recorded
announcement, or route to attendant). If the originating party is a local
attendant, busy indication is given. At this point, the DPNSS1 Attendant
Camp-on feature may not be used.
If a Meridian 1 transit node receives an Initial Service Request Message that
does not contain a Loop Avoidance Supplementary Information String,
before the ISRM is sent over a new channel, a Loop Avoidance
Supplementary Information String is added to the ISRM. The Loop
Avoidance parameter is set to the pre-defined Loop Avoidance limit (as
programmed against the TNDM prompt in the Customer Data Block, overlay
15) less one, to account for the incoming DPNSS1 channel.
The Loop Avoidance Supplementary Information String is ignored at a
terminating Meridian 1 node that is not a gateway. If a terminating Meridian
1 node is a DPNSS1 to ISDN gateway, then the call is cleared back if the loop
avoidance limit has been reached. If the ISDN Call Connection Limitation
(ICCL) feature is equipped, the Loop Avoidance Limit is used to create the
ICCL Tandem Threshold Limit in the outgoing SETUP message.
Operating parameters
— The intercept treatment for Network Alternate Route Selection calls that
are blocked, configured in overlay 15 in response to the INTR prompt,
should be the same as that for calls receiving Loop Avoidance call-back
treatment, configured in overlay 15 in response to the CONG prompt.
Feature interactions
— Calls extended by the attendant across a DPNSS1 trunk contain a Loop
Avoidance String, with the value of the loop avoidance parameter being
customer-defined in overlay 15.
Option 11C 2.0 Mb DTI/PRI Administration and Maintenance guide