Bug #6442
closedSGSN does not answer to first GMM ATTACH REQUEST
0%
Description
Hello, I'm trying to setup a 3G network following your "Network In The Box" tutorial/documentation.
I use an ipaccess nano3g S16 femtocell and the components required to have a 3G network :
- HLR
- MSC
- MGW
- STP
- HNBGW
- SGSN
- GGSN
I have a "working" setup because I can browse the internet from a Phone using my 3G network. However, I have the following issue :
- Any phone takes approximately 1 minute 40 seconds to have 3G data (SMS connection is almost instant).
More precisely, I investigated a bit and found :
- A first GMM ATTACH REQUEST is received by the SGSN
- Some stuff is happening with the HLR to get crypto params and dealing with subsciber data up to the UpdateLocation Result message
- Meanwhile, some SecurityModeCommand is sent to the femto
- However, the femto answers with a SecurityModeReject message, and after that, the SGSN does not respond to the GMM ATTACH REQUEST
- Then, the SGSN receives a new GMM ATTACH REQUEST every 15 seconds and does not respond to theses as well (4 attach requests in total)
- Finally, after some time, a Iu-ReleaseRequest is received and it triggers a PurgeMS with the HLR.
- After that, a new GMM ATTACH REQUEST is received and is treated sucessfully by the SGSN (no SecurityModeReject and an ATTACH ACCEPT is sent)
- In total, it took around 1minute and 40seconds to get 3G data on the phone
I tried to reboot everything, re-regsiter the SIM info in HLR etc... But I suspect the SecurityModeReject that maybe is an issue with the femtocell ?
I put the SGSN logs and the HLR logs, but I can upload the PCAP with SCTP and GSUP packets.
Do you have an idea of what is happening ?
Thanks in advance
Files