"PS Activation" takes long time - missing Iu-Release Command after Attach Complete
I've noticed that it takes around 10 seconds for PS to work after a phone becomes registered on the network. Basically, the phone waited for 10 seconds after Attach Complete message and then sent Iu-ReleaseRequest and only then Service Request. (after Iu-Release completion)
If I send the Iu-ReleaseCommand (diff file sgsn-iu-release-after-attach-complete.diff, applied to 1.4.0) upon receiving Attach Complete message then the phone sends Service Request right away after Iu-Release completion.
RANAP trace without the fix - without-fix.pcap (Attach Complete - packet # 73 - there you see around 10s delay betweenand the phone sending Iu-ReleaseRequest)
RANAP trace with the fix - with-fix.pcap (Attach Complete - packet # 43)
gsm0408_rcv_gmm: send Iu-ReleaseCommand upon receiving Attach Complete.
UE expects to receive Iu-ReleaseCommand after Attach Complete. If it
doesn't receive it, then it sends Iu-ReleaseRequest after a timeout
which makes the "PS Activation" process long.