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View Full Version : TCH BLOCKING AFTER CHANGE TCHF TO TCHD IN NSN



atese
2012-01-18, 02:51 PM
Hello guys.

I have a special case in a 2G NSN sector with 2 TRX, all TSL were in FR mode, I reconfigured the TSL from TCHF to TCHD. Since that moment. TCH blocking begins. previously TCH blocking was not present.

The counter that increased after this reconfiguration was 001122 / TCH REJ DUE REQ CH A IF CRC, I made the rollback and returned all TSL to TCHF and TCH blocking and counter 001122 activity stops.

Does anyone know why this behavior?.

This is the explanation of the counter 001122: Number of requests for TCHs that are rejected because of a mismatchbetween the types of the requested channel and the A interface circuit, whether queuing occurred or not.

I made other reconfigurations of TSL in others sectors, and this behavior never happened.

Any comments are welcome.

louvre
2012-01-19, 12:37 AM
As the error encountered suggest it a circuits issue, now mostly it occurs due to mismatch in A IF circuits now you have given additional info that its fine in other sector but it not clear whether other sector from other site or other sector from same site.. if first is the case then i would suggest u to delete the trxs and lapd and re create this will clear any circuit mismatch within BSC..

Before that try to do one more thing.....

try to create a TCHD TS in another site altogether afresh and see if you get the same problem.

if the counter then get increased.. then there are 3 - 4 causes.

Manly BSC concurrent traffic channel capacity exceeded -- i.e. BSC re dimensioning.
Soft channel capacity maynot be there -- i.e. licenses issue or missing feature.

if missing feature then add more physical trx licenses and it might get solved.. TCHF actual reserves one physical TS in the BSC and TCHD reserves 2 !!!!! so it makes a difference if you don't have soft channel capacity.!!!!!

hope it si useful for u. :)

stream19
2012-01-19, 07:26 AM
do u have AMR configured?

oswe
2012-01-19, 10:52 AM
talk to a good MSC guy... they solved that problem for me...:D

atese
2012-02-03, 02:36 PM
Thanks Louvre, finally it was a configuration issue in TRX`s, we deleted and created again and problem was solved