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19th March 2010 at 09:18 #61601AL CATELGuest
We are facing from huge call drop rate due to BSS internal fail on one BSC.The call drop rate due to this reason is almost 20-25% from whole CDR. Vendor – Alcatel (B10).
Thanks in advance
BR19th March 2010 at 09:42 #61602ATTOGuest
Can u provide us information about your BSC generation : G2 , MX etc…
All cells from this BSC are concerned ??
Regards.19th March 2010 at 10:08 #61603AL CATELGuest
BSC is G2 and all cells from this BSC are affected.The number of drops due to internal fail per cell is depending on cell traffic (more traffic – more drops).
BR19th March 2010 at 10:33 #61604ATTOGuest
Your problem is really weird; Generally when u got huge drops BSS on all cells of one BSC the cause is ” BSS RTC drops ” but not ” BSS internal fail”.
Anyway, u should look for BSC internal cards like swch, tcuc etc…
Check for alarms too on the related bsc.
Regards.19th March 2010 at 10:59 #61605pixGuest
the causes of internal failures are :
1) Whenever an 48.058 ERROR REPORT message with a cause value of ‘O&M intervention’ is received on Abis interface after TCH seizure and leads to a loss of call.
2) Whenever an 48.058 ERROR REPORT message on SAPI 0 with a cause value of ‘message sequence error’ is received on Abis interface after TCH seizure and leads to a loss of call.
3) Whenever a LAPD failure is reported to the Layer 3 of the BSC (for an RSL supporting a TCH transaction after successful TCH seizure) and leads to a loss of call.
4) Whenever a TCH call release is initiated by the BSS O&M FAULT MANAGEMENT application part or by the BSS TELECOM application part as the result of a system defense action which may be due to BSS equipment failures external to the BSC (e.g. RSL failure or CU recovery failure), or due to BSC internal hardware problems (e.g. TCU failure or DTC failure) or due to BSC internal software problems (e.g. inconsistencies detected between software modules or lack of software resources (memory, timer reference, file reference…) or communication problems between different processor boards).
most of the time, it is O&M actions, but it could also be boards of BSC of software of BSC failures. Check also your RSL congestion or quality ? (usually, if the RSL fails, the rest of the Abis also fails though)…
anyway, for this kind of sudden degradation, it is probably boards or software in BSC.2nd October 2010 at 22:03 #61606GALSENGuest
Hi, in that case you have in general two possibilies :
1 – check if you have an alarm on a switch board (alarm routine test, swith-fail, …) and lock it
2 – check if you have at least one cell id of this BSC misconfigured at MSC side with wrong cellid, lac, or BSC SPC (Semaphore Point Code)
Regards19th June 2011 at 07:10 #61607SHIZGuest
We want to activate Equivalent PLMN in Siemens MSC.Wold you please guide me about parameters?