OsmoSGSN » History » Version 1
laforge, 02/19/2016 10:48 PM
add osmosgsn page
| 1 | 1 | laforge | [[PageOutline]] |
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| 2 | = OsmoSGSN = |
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| 4 | OsmoSGSN (also spelled {{{osmo-sgsn}}} when referring to the program name) is a Free Software implementation of the GPRS |
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| 5 | Serving GPRS Support Node (SGSN). As such it implements the GPRS Mobility Management (GMM) and SM (Session Management). |
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| 7 | The SGSN connects via the Gb-Interface to the BSS (e.g. the ip.access nanoBTS), and it connects via the GTP protocol |
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| 8 | to a Gateway GPRS Support Node (GGSN) like [wiki:OpenGGSN]. |
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| 10 | It is currently very experimental. The Gb protocol stack and the LLC implementation are quite robust, and signalling |
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| 11 | for GMM and SM seems to run pretty fine. However, the user plane including SNDCP fragmentation is in pre-alpha quality. |
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| 13 | OsmoSGSN is part of the openbsc git repository. In order to build it, you will need a libgtp installation from the |
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| 14 | OpenGGSN project. |
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| 16 | == TODO list == |
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| 17 | * use the HLR to identify (and possibly authenticate) subscribers |
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| 18 | * proper error messages in SM (e.g. activation of an already active PDP context) |
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| 19 | * secondary PDP contexts |
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| 20 | * proper de-fragmentation of segmented SN-PDUs into N-PDUs |
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| 21 | * support for multiple GGSNs |
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| 22 | * persistent storage of GMM and SM state |
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| 23 | * recovery from GGSN outages |
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| 24 | * SNDCP header and data compression |
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| 25 | * use proper XID exchange and actually use the results to configure the LLC SAPIs |
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| 26 | * GEA3 encryption |
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| 27 | * make sure LLC and SNDCP entities are cleaned up on PDP CTX DEACT |
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| 28 | * make sure PDP contexts are deactivated on IMSI DETACH |
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| 29 | * PS PAGING in case MS has entered GMM-SUSPEND |
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| 30 | * SMS delivery via GPRS |
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| 31 | * network-initiated PDP context activation |
