I have a severe problem of poor GPRS Attach Success.
1. What are the reasons for Attach fail?
2. There are 2 counters that show exceptionally high values
There is no documentation available anywhere.
1.Illegal MS,LA not allowed,Illegal ME,GPRS service nor allowed,Gr fail,Ge fail,No suitable cell in LA & protocol error.
To answer the 2nd part,can I know what are the reasons for Attach failure in your system
Amongst all the failure causes given by you, I have already checked & found that failures are more due to the already mentioned counters. There is no hard blocking & soft blocking is well under control!
And I am looking for the reasons for the attach fails!!! RF part is being considerably taken care of..But I am doubting the behavior & communication of SGSN with self & other fellas.
Sorry for the late reply Bijoy. The site seemed to be down for some days. Anyways, just to share with you, I changed the INIT MCS (DL/UL) from 6/5 to 2/1 & I got good improvement in the Attach Success rate!!!
well m a bit confused, as the error causes that you had mentioned (FAIL_GPRS_Attach_Due_SGSN_ERR & FAIL_GPRS_Attach_HLR_VLR_ERR) are purely core end and protocol related issues, so how come changing initial coding schemes improved the attach success rate? did u see improvement in VLR and SGSN errors as well or they are intact…???