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The GPRS load of the impact BSC and feedback if we can perform WA on one BSC:
A specific BSC data structure linked to GPRS DTCs is coded over 1 byte meaning that it should be limited to the value of 255. In the case of a Conf 5, the number of DTCs goes over 255. Whenever there is a high load transmistion allocation/deallocation from MFS, BSC will release an incorrect DTC reference and reject further allocations. In extreme condition, the degree will be (320-255)/320=20%. (320 is the maximum GPRS DTCs with CONFIG 5).
When we said 20% Degradation, it was implied extreme conditions, that means when all CPUs are 100% busy or all buffers in DTCs are occupied, but R&D do not think we can reach that load level.
So generally speaking, there should be no congestion if we disable those DTCs.
Workaround:
- Reduce the number of GPRSAP DTC to 255 (BSC HE43 has 280 GPRSAP DTCs) by modification the relation R_GPRSAP_C then trigger a BSC reset.
- Please note that the GPRS capacity will be effected if using this WA as the number of GPRSAP DTC is reduced.
Method to modify DLS: For the Tuple > 254, Modify R_GPRSAP_C.D_LCE_ID = H'FFFF (Note: Tuple 255 also need to be modified as 255 is FF in hex which is used as a dummy value in code).
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