Project

General

Profile

Accelerate3g5 -- neels » History » Version 12

neels, 03/03/2017 12:18 AM

1 1 neels
h1. Accelerate3g5 -- neels
2
3
{{>toc}}
4
5
h2. Summary
6
7
Implement Osmocom 3G support integrated with the new libvlr, so that standard USIMs with full UMTS AKA can be used with the 3G OsmoMSC.
8 7 neels
This is actually a prerequisite for the accelerate3g5 contestants to be able to use their USIMs with the nano3G (without going into reprogramming it).
9 1 neels
10 2 neels
h3. Participants
11
12 12 neels
* Neels (email: nhofmeyr@sysmocom.de  jabber: nhofmeyr@im.sysmocom.de )
13 2 neels
14 1 neels
h2. Details
15
16
For various reasons, the previously integrated HLR functionality is currently being split from OsmoNITB, on the "neels/vlr":http://git.osmocom.org/openbsc/log/?h=neels/vlr branch. UMTS AKA using the Milenage algorithm already works for 2G using that branch, but the "sysmocom/iu":http://git.osmocom.org/openbsc/log/?h=neels/vlr branch still lacks this capability.
17
18
Rebase the sysmocom/iu branch onto the neels/vlr branch and resolve all conflicts. Test and verify that 3G works with the sysmoUSIM-SJS1 using Milenage authentication.
19
20
Related issues are: #1595 #1711 #1593
21
22 8 neels
Work-in-progress is kept on the openbsc.git:neels/iu branch.
23
When done, this will become the new sysmocom/iu branch.
24
25 1 neels
h2. Journal
26
27
_2017-02-28_
28
A first @git rebase@ resulted in numerous conflicts. Starting to resolve...
29
30 3 neels
_2017-03-02_
31
Conflicts have been resolved, but of course the result doesn't compile.
32
Fixing all the errors, and will then need to test+debug, and also review all patches in detail.
33
Rate counters and the logging context are at least incomplete, probably more details and corner cases.
34 4 neels
_later_
35
The merged branch compiled. Now the msc_vlr unit tests fail and there are probably still many other errors to resolve.
36 3 neels
37 1 neels
h2. Conclusions
38
39 9 neels
* I thought that GERAN means exactly A-interface and UTRAN means Iu-interface. But there's also GERAN-over-Iu.
40 10 neels
  RAN is the radio technology, so GERAN _does_ mean 2G BTS, but A and Iu are just the interfaces that these can be controlled over.
41 1 neels
  An MSC may employ an Iu interface to talk to both GERAN and UTRAN radio technology infrastructure.
42 10 neels
  See the new enum ran_type: so far OsmoMSC will support RAN_UTRAN_IU. We hope to add RAN_GERAN_A soon. There are no plans in sight to add RAN_GERAN_IU.
43
  The traditional OsmoNITB is BSC and MSC welded together, so it's more like GERAN over Abis.
44 5 neels
45 9 neels
* And I thought that UMTS means 3G means UTRAN, but UMTS is "just" the R99 (Release 1999) extension of the protocols.
46
  UMTS is used in 3G/UTRAN, yes, but for example UMTS Authentication can be negotiated over 2G networks. I know now because I implemented it.
47
  As soon as the MSC says it is R99 capable in the SI3 MSCR bit and the MS is operated with a USIM which "replies" that it is R99 capable in the Classmark IEs sent during Location Updating, CM Service Request and Paging requests, both sides can/will authenticate using UMTS mutual authentication -- another prerequisite of course is that the HLR has UMTS authentication keys stored for this USIM.
48 5 neels
49 9 neels
* _todo: have the same UMTS auth over actual UTRAN+Iu_
Add picture from clipboard (Maximum size: 48.8 MB)