Commit Graph

8 Commits

Author SHA1 Message Date
Pau Espin 5557c0af80 Support Neighbor Address Resolution over PCUIF IPA multiplex
While NACC was initially developed, it became clear there was need for
a way to interact PCU<->BSC in order resolve ARFCN+BSIC into CGI-PS
for later RIM usage.
Hence, this resolution was first (until today) implemented using an out
of bands RPC system using the CTRL interface, which required specific
config to be written and matches in osmo-pcu and osmo-bsc VTY (ip+port
of the CTRL interface to use).
However, this has several shortcomings:
* As explained above, specific configuration is required
* Since recently, we do support BSC redundancy in osmo-bts. Hence the BTS
  may switch to a BSC other than first one. If that happened, that'd mean
  the CTRL interface would still point to the initially configured one,
  which may not be the same currently serving the PCU.

During recent development of ANR related features, a similar need for
PCU<->BSC was required, but this time it was decided to extend the IPA
multiplex of the Abis OML connection to pass PCUIF messages,
transparently forwarded to each side by the BTS.
This has the advantage that connection PCU<->BTS is handled by BTS and
both sides send messages transparently.

Let's switch by default to using this new interface, while still
maintaing the old way for a while (announcing them as deprecated) to
avoid breaking existing deployments until they are upgraded to new
versions of osmo-pcu and osmo-bsc.

Related: SYS#4971
Change-Id: I6ad33c7ab10202840cf804dea9ba595978d0e920
2021-09-13 13:31:06 +02:00
Pau Espin Pedrol fe8de457ac Use ALPHA value received in SI13 from PCUIF
The old VTY command is marked as deprecated and still overrides the use
in case it's used.

Related: SYS#5358
Depends: libosmocore.git Change-Id I74fb0a3afc1ac4aadbfc609b882d929401f790eb
Depends: osmo-bsc.git Change-Id I8b97ea11bad5fe05f2f634945b5703ee9abde81d
Change-Id: I46f2a955b157a409055fca7fb917dc4f75482426
2021-02-22 12:29:12 +00:00
Pau Espin Pedrol 44768f2127 nacc: Avoid RIM procedures targeting cells under same PCU
Now that we have the required System Information in osmo-pcu to craft
the Packet Neigbour Cell Change packet for cells it controls, let's
avoid starting a RIM procedure to gather the SI info, since the SGSN
would end up routing the RIM request back at us and we'd answer back to
ourselves.

This same optimization cannot be done on the first step (CTRL Neighbor
Resolution against BSC), because the PCU cannot know if the target
ARFCN+BSIC requested by the MS is actually managed by a cell under the
PCU or it's another cell managed by another external PCU, because
ARFCN+BSIC keys can be resued among non-neighbor cells. Hence, it shall
always ask the BSC since only it holds the information about neighboring
cells.

Related: OS#4909
Change-Id: I928875b6b66dff55fc12f51b6b1ad919fef7d03b
2021-02-03 08:34:12 +00:00
Pau Espin ced5c1f5c8 doc: Introduce section documenting NACC support
Change-Id: I74e4828ed1b99a7f4d28ea4797c93ee85c0068cb
2021-01-29 15:52:44 +01:00
Pau Espin Pedrol d3123ea0f5 doc: Improve CS/MCS GPRS/EGPRS considerations in User Manual
Related: OS#4544
Related: SYS#4869
Change-Id: I7b205f5cab5862058a408f628925beb9f0f60a92
2021-01-05 15:48:58 +00:00
Philipp Maier 452b533114 configuration: fixing typos
configuration.adoc has some minor typos in it, this commit fixes
that.

Change-Id: Id84238b89e5deeac99c043b79b26c7e7b8b8534b
2018-11-27 18:30:23 +01:00
Jonathan Brielmaier 58721eb350 fix various typos across all manuals 2018-11-27 18:30:23 +01:00
Harald Welte 4ff37feb4c initial checkin of manuals to public repo
The manuals existed in different form for several years in an internal
sysmocom repository.  However, since they had just recently been
converted from docboox-xml to asciidoc and all files have been
re-shuffled for enabling the public release, there's not much point in
keeping the history with git-filter-branch.
2018-11-27 18:30:23 +01:00