the near and further future of osmo-nitb

Hi all, I would like to direct your attention towards upcoming fairly fundamental changes that we would like to make in openbsc.git. The operation of osmo-nitb will need some adjustments that might stump some users at first. Hence, I would like to ask your feedback on this. While these changes open the road forward in exciting ways, to some degree they constitute a code bomb and a point-of-no-return. Let's discuss, to be prepared for it. (1) Near future: We are separating the HLR from OsmoNITB, aka libvlr + OsmoHLR. This gets us asynchronous HLR database access, 3G authentication and one central HLR for both OsmoNITB and OsmoSGSN (at some point also several OsmoNITBs). OsmoNITB will no longer manage its own SQlite subscriber database. OsmoHLR is a separate process that manages subscriber data, which the OsmoNITB as well as the OsmoSGSN will contact using the GSUP protocol. On the OsmoNITB side, libvlr implements a VLR with a brand new finite state machine implementation of handling attach, authentication and ciphering on a subscriber connection. libvlr stores subscriber data solely in RAM. (Note that at first, OsmoNITB will still have an SQlite database file, which will be used for storage of SMS data, only.) The main changes in operating OsmoNITB will be: - A separate osmo-hlr process with its own hlr.db database needs to be run. - The osmo-nitb VTY (telnet localhost 4242) and CTRL interface will no longer allow changing subscriber data; good old commands like 'subscriber create imsi 1234', 'subscriber imsi 1234 authorized 1' and so on will no longer be available. All subscriber management must be done on the OsmoHLR side. Since OsmoHLR so far has no VTY or CTRL API to manage subscribers, that needs to be done via sqlite3 on the hlr.db file (or re-implemented for OsmoHLR). Since this will constitute a profound change in operating an Osmocom CN, it makes sense to think about ways to transition. We're planning to make the VLR+HLR branch the new 'master' branch of openbsc, while keeping the current master on a legacy branch (named something like v1, which implies that the new flavor is Osmocom v2). We do not indend to spend much effort on maintaining the old flavor, though. Ongoing development and new features will happen in the new libvlr+OsmoHLR flavor, only. To take a peek, see the openbsc.git branch 'neels/vlr' and OsmoHLR at http://git.osmocom.org/osmo-hlr/ . (2) Further plans: For Iu and A interfaces (a standalone 3G+2G MSC implementation), we have also worked towards a complete separation of libmsc from libbsc. As a result, we will probably completely replace OsmoNITB with the new OsmoCSCN, meaning "Circuit Switched Core Network", which will be mainly MSC+VLR, talking to OsmoHLR for subscriber data, and to OsmoBSC and/or OsmoHNBGW to manage GERAN (2G) and/or UTRAN (3G) radio services. The main changes in operating an Osmocom CN will be: - Instead of running OsmoNITB, run separate OsmoBSC, OsmoCSCN and OsmoHLR instances. - VTY configuration of the BTS parameters needs to be done on the OsmoBSC level. - Logging on the MSC level will no longer have intimate access to BSC and BTS details. It is thinkable to still offer an OsmoNITB that integrates BSC and MSC+VLR, but the focus is elsewhere. - There will be Iuh (3G) support; IuCS in OsmoCSCN (sysmocom/iu branch), IuPS in OsmoSGSN (already merged to master, 3G Authentication pending). - It will be possible to operate a real A interface towards other standalone BSCs. This will at first stay on the sysmocom/iu branch, and cannot be merged to the master branch before we have a fully operational A interface. To take a peek, see http://osmocom.org/projects/cellular-infrastructure/wiki/Getting_Started_wi… Your feedback and opinions on these plans are welcome! ~N -- - Neels Hofmeyr <nhofmeyr(a)sysmocom.de> http://www.sysmocom.de/ ======================================================================= * sysmocom - systems for mobile communications GmbH * Alt-Moabit 93 * 10559 Berlin, Germany * Sitz / Registered office: Berlin, HRB 134158 B * Geschäftsführer / Managing Directors: Harald Welte