Lucent Technologies 555-661-150 manual Possible Cause 2 Callback Queuing is not used

MERLIN LEGEND Communications System Release 6.1	Issue 1
Network Reference 555-661-150	August 1998
6 Troubleshooting
Call to Non-Local Extension: Silence or Fast Busy Tone	Page 6-7

than routes that specify tandem facilities, you may need to adjust extension and route FRLs in order to restrict access to them. Be sure that you discuss any changes with the coordinating system manager.

■If the routing is correct and enough routes are included in the pattern, but the problem persists, check if PRI lines are used. If they are, check the error log for D-channel inoperative and loss of signal alarms indicating lines are inoperative. If the D-channel inoperative alarm has occurred, check the CSU/DSU associated with the line for correct programming. If the loss at signal alarm has occurred, check for open cables, etc. If these conditions are not present, go to Possible Cause 3.

Possible Cause 2: Callback Queuing is not used.

What to Do: All available local routes for the call may be busy, and Automatic or Selective Callback allows the call to queue for the next available tandem trunk assigned to the Route 1 pool. As a first step, the caller should try using Callback.

If a user is having trouble with the Callback feature, see “Callback Does Not Work” on page 20.

Possible Cause 3: Not enough trunks are assigned to the pools for UDP routes.

What to Do: To verify, check the error log for pool busy errors (such as 4c02, Pool

Busy). Consult System Form 2c, System Numbering: Line/Trunk Jacks to determine the assignments. To see a report of pool assignments, select the 3ULQW option on the System Programming menu and then choose￿7UXQN￿,QIR￿and￿ *HQHUDO.

■If more trunks are available and need to be assigned, follow the procedure in “Trunks to Pools Assignment” in Chapter 4 of System Programming to assign more tandem trunks. All the tandem trunks in a pool must be of the same type (tie or PRI).

■If not enough trunks are available, consider adding more to your system.

■If there are sufficient trunks assigned but the problem persists, go to Possible Cause 4.

Possible Cause 4: Facilities are available but restricted and the caller is not able to access them.

What to Do: Verify that the extension’s FRL is higher than or equal to the UDP route FRL.

If you want to make changes in FRLs for routes, speak with the coordinating system manager for your private network and consult the following resources:

■“How Facility Restrictions Levels Work in a Network” on page 9 discusses FRL planning in detail.

■To change a UDP route FRL, see “Uniform Dial Plan Routing” on page 25 or “UDP Routing” in Chapter 4 of System Programming.