NANC 320

NPAC Retries when Local System is in Congestion

Origination Date :11/01/2000

Originator:ESI

Description:

A local system may experience a transient overloaded condition that will cause its message input buffer to fill. This should be allowed as long as that local system can maintain the average rate over the timeout period, which is currently a 15-minute period. If that local system is not allowed to use any flow control, then it must be over engineered to assure that no momentary burst of messages from the NPAC could exceed its buffering capacity.

Final Resolution:

Func Backwards Compatible:  ???

Currently the NPAC attempts to send a message to a local system and if that system happens to be momentarily in congestion, then the NPAC will count the event as an attempt but the message is never seen by the local system. In a 1 x 15minute environment, this attempt to broadcast will exhaust the retry count resulting in an abort of the association and subsequent need to re-associate and recover any messages sent during the re-association. The NPAC needs to guarantee delivery of that message after the local system emerges out of congestion. This will allow for a successful broadcast within the defined time window and avoid the extra processing for both the local system and the NPAC caused by the re-association and recovery.

November 00 Meeting: The stack of the sending system knows when the other system is in congestion. This is part of the ‘stack’ tool kit.  The sending system can see that the other system is X messages behind.  If a Service Provider system is in congestion when the NPAC sends a message, that message is lost because even though it is queued up there is no retry to send it later – this is the fall out of the 1 X 15 timer.  This problem could be partially solved with a multiple retry environment.

December 00 Meeting:  The group was informed that NeuStar had implemented a NPAC fix in the Release 3.0 software that would take care of this problem.  Based on this information the change order was withdrawn and moved to Cancel-Pending then Closed/No Action.

January 01 - Removed from the list by LNPAWG.

Related Release:

N/A

Status: Closed