Changes

SGSN: BSSGP_ConnHdlr: GMM Service Request: handle PMM IDLE UE correct

24.008: 4.7.13.3: explicitly mention the completion of the low layer security to be an implicit
Security Command Accept if the UE is in PMM Idle.
Extend the as_service_request() to handle both cases when UE is in PMM-IDLE as well in
PMM-CONNECTED.

Change-Id: I29237997e414aea80f254247da54f909410a4b36

SGSN: BSSGP_ConnHdlr: GMM Service Request: add support to expect authentication

On a Service Request, the authentication is optional.
Either an authentication must happen or the key material from the previous authentication
has to be used.
The default behavior is still the same.

Change-Id: I9ed08160bf5413e3a30d6e90eb947d4d799e1058

SGSN: BSSGP_ConnHdlr: f_gmm_attach(): allow the SGSN to request the IMEI

The IMEI might be requested when the GMM Attach happen.

Change-Id: Id49c9e6ef7517a6a831315ac1f9915c50b88beb6

SGSN: f_TC_attach_timeout_after_pdp_act: allow authentication

While testing, allow the SGSN to authenticate the UE.
The new VLR code will authenticate the UE, while
the old code doesn't.

Change-Id: I11c628ecebbe7c4c1b2c28e63133a33cfc171e12

SGSN: f_TC_attach_rau: do a periodic RA update instead of RA change

After an attach, the periodic RA would be the correct.

Change-Id: Ic33687c55915d883b6d9a9a0d640a11588e1d1a0

SGSN: TC_attach_auth_id_timeout: set TMSI to provoke a ID Request

This test case simulates a MS which ignores Identity Requests. To ensure
the SGSN will ask for the IMSI, do an Attach Request with id TMSI.
Later this ID Request (type IMSI) will be ignored and the test case
expect a Attach Reject.

Change-Id: I5a860582aa57ebc073e4c33f3f2f8884e360edef

SGSN: f_TC_hlr_location_cancel_request_withdraw: drop incorrect Update Location response

This PDU was a Copy/Paste mistake and never been expected or used. The SGSN ignored
this message.

Change-Id: Ib8265416c650b0983d7e85786b334f84191331b2

SGSN: f_TC_paging_ps: call f_gmm_attach() direct

Instead of using the TC function, call f_gmm_attach() direct.
Also set explicit the verdict at the end.

Change-Id: I68c75f84b01a0cd673ffd8c19ab5f0a8517c5738

SGSN: f_TC_cell_change_different_*: always expect the auth

The new SGSN will always ask for authentication when receiving Attach or RA
which is the correct behaviour as long the LLC layer doesn't indicate
integrity or encryption protection.

Change-Id: I24579b5fc843caf68e035e106cee4e4ec0a3c735

SGSN: fix encoding of IMEISV in Auth and Ciphering Response

According to 24.008 the IMEISV field is exact 11 bytes long and
must contain a IMEI + SV which is exact 16 digits long, not 15.

Change-Id: I79dd79840de58f450c1a05e704fd9bd831455716

SGSN: TC_attach_pdp_act_pmm_idle: use correct Service Request type

When the UE requests data service, it must use the data service request type.

Change-Id: I9301e7a37d96c3f93e77f7618d6c13dfa1fbe46b

SGSN: Context Req In: use correct TEID-C

For a MS/UE moving from 2G to 4G, the Ctx Acks need to transmit
with the correct TEID-C which the SGSN chose in the Context Response.

Change-Id: I84dc7dda8ee1227edd68d1482a4c5bf267c16418

SGSN: assign random TEID-C to Context Req/Resp/Ack messages

Change-Id: Icac28280a810e8d24eeeaaae1fb1a15278fde8da

SGSN: Remove mm context triplets

Only triplets which hasn't been used should be included.
The MME will only request and sent back a single set of tuples.
There shouldn't any left overs.

Change-Id: I60a3331396cb9905ec9a4df9b1e65a3291a51058