Hi Neels,
D-GSM proxy cache -- if you have the time, feedback on
this design document would be appreciated:
http://git.osmocom.org/osmo-hlr/commit/?h=neels/dgsm&id=8071c561405a031…
(when that commit is checked out, building osmo-hlr with manuals enabled should render
the ladder diagrams in proxy_cache.adoc, which illustrate what I'm planning to
implement)
(and disregard "(7) Skip the Insert Subscriber Data", as explained in the
prose)
I like that the key of the home HLR is not shared with the proxy HLRs.
All in all, it sounds like a very smart solution!
Some notes:
* In the ladder diagrams, it shows that the AKAs are cached in both the
MSC and the HLR. Why not just cache them in the HLR?
* It might be a good idea to make AKA reuse optional with a VTY config
option?
* Potential use case: phone is home in village A, gets turned off, owner
travels to village B with the phone, the link to village A is down.
Phone gets turned on, then there will be no AKAs cached in village B's
(proxy) HLR and the LU will fail. But there does not seem a way around
this without sharing the keys (or without spaming other HLRs with AKAs
for all subscribers in the HLR that they might use in the future, but
that would just waste traffic).
Regards,
Oliver
--
- Oliver Smith <osmith(a)sysmocom.de>
https://www.sysmocom.de/
=======================================================================
* sysmocom - systems for mobile communications GmbH
* Alt-Moabit 93
* 10559 Berlin, Germany
* Sitz / Registered office: Berlin, HRB 134158 B
* Geschaeftsfuehrer / Managing Director: Harald Welte