Hi Osmocom Community.
I'd like to extend the SMPP protocol alert notifications to be able to differentiate between IMSI_ATTACH, NORMAL and PERIODIC LURs
The reason is to be able to react to an initial attach by sending a "Welcome" SMS.
SMPP specifies only three status possibilities:
0 = Available
1 = Disabled
2 = Not Available (Detaching)
I've added 3 for IMSI_ATTACH - Actually I ended up using != PERIODIC because not all phones send an ATTACH after a DETACH, some send NORMAL LUR.
With this the ESME can respond to an alert notification that has status 3 by looking up the IMSI to see if it's known/autorised etc (this is outside of osmo-hlr in my use case, although I guess it could also be done by checking what the HLR says inside the MSC)
Anyway.. I'm wondering if anybody else ever did this, and do we want/accept this functionality in master osmo-msc?
Or.. any better ideas on how to do it?
Thanks
k/
Hi Keith,
On Wed, Jan 13, 2021 at 01:25:12AM -0600, Keith wrote:
SMPP specifies only three status possibilities:
0 = Available
1 = Disabled
2 = Not Available (Detaching)
I've added 3 for IMSI_ATTACH - Actually I ended up using != PERIODIC because not all phones send an ATTACH after a DETACH, some send NORMAL LUR.
I think it might make sense to add a new IE/TLV as a sub-type of "Available", this way I would think it's more compatible to other implementations as additional IEs are typically simply ignored.
Furthermore, I'm not convinced your !=PERIODIC will do what you want, as NORMAL will also happen between location areas, so neither ATTACH nor PERIODIC.
One idea is to add logic to osmo-msc to distinguish whether this really was a new subscriber that was previously unknown to the MSC (and Then send "Available"), or simply send no SMPP notifiation at all if the subscriber was previously already known to osm-msc. This way no protocol changes need to be introduced at all.
The alternative would be to add a new, non-standard IE whihc just passes the LU type transparently through.
do we want/accept this functionality in master osmo-msc?
I think either of the two ideas I outlined above could go master.
Regards, Harald
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Harald Welte -
Keith