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• OsmoSGSN

OsmoSGSN¶

Serving GPRS Support Node (SGSN).  As such it implements the GPRS Mobility Management (GMM) and SM (Session Management).

The SGSN connects via the Gb-Interface to the BSS (like the [[osmo-pcu]] or an ip.access nanoBTS), and it connects via the GTP protocol
to a Gateway GPRS Support Node (GGSN) like [[OpenGGSN]].

[[OsmoSGSN]] is part of the openbsc git repository.  In order to build it, you will need a libgtp installation from the
[[OpenGGSN]] project.  

h2. Setup / Configuration

For more information regarding the setup + configuration, refer to [[OpenBSC_GPRS]]

h2. TODO list

* use the [[OsmoNITB]] HLR to identify (and possibly authenticate) subscribers
* secondary PDP contexts
* persistent storage of GMM and SM state
* recovery from GGSN outages
* SNDCP header and data compression
* use proper XID exchange and actually use the results to configure the LLC SAPIs
* GEA3 encryption
* SMS delivery via GPRS
* network-initiated PDP context activation