Commit Graph

8 Commits

Author SHA1 Message Date
Philipp Maier 085a92584f heighbor_ident: add/del neighbor cells via ctrl interface
The VTY allows flexible control over the neighbor cell information via
the neighbor command, which can be found in the configure terminal under
the bts node. Lets add pendant of this command on the control interface
as well.

Change-Id: I343a40e18fa9b91e6c381912c0426a002841e079
Related: SYS#5641
2021-11-03 17:25:28 +00:00
Pau Espin 506aa70d77 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.

Change-Id: I9073a121564503f483c84263ac72476041e47c03
Related: SYS#4971
2021-09-13 16:04:05 +02:00
Neels Hofmeyr 764449ec2e fix/refactor neighbor config
The neighbor configuration storage is fundamentally broken: it requires
all local cells to be configured before being able to list them as
neighbors of each other. Upon config write-back, the neighbor config
however is placed back inline with the other config, and hence a
written-out neighbor config no longer works on program restart.

The cause of this problem is that the config is stored as explicit
pointers between local cells (struct gsm_bts), which of course requires
the pointer to exist before being able to reference it.

Instead, store the actual configuration that the user entered as-is,
without pointers or references to objects that need to be ready. Resolve
the neighbors every time a neighbor is needed.

Hence the user may enter any config at any place in the config file,
even non-working config (like a BTS number that doesn't exist), and the
relation to actual local or remote neighbor cells is made at runtime.

Abort program startup if the initial neighbor configuration contains
errors.

Related: OS#5018
Change-Id: I9ed992f8bfff888b3933733c0576f92d50f2625b
2021-03-24 21:22:21 +01:00
Pau Espin Pedrol a27e8a5c9a Move bts_ident_key to neighbor_ident.c
The function is not really handover specific, and will be used in other
places in subsequent patches.

Change-Id: Icae8b9045e497f850f22cb3b6f93acbf61b84746
2021-02-13 08:15:01 +00:00
Pau Espin Pedrol 55a015dddf Introduce Neighbor Resolution Service
This new CTRL interface allows users of this BSC (such as attached PCU)
to gather neighbor information.

This interface is needed for PCU to translate ARFCN+BSIC keys provided
by MS in the Um side into CGI + RAC keys used to identify target cells
in RIM procedures against SGSNs on the Gb interface.

This patch extends the already existing neighbor information storage in
the VTY by allowing storage of CGI + RAC (RAC couldn't be stored
beforehand).

Related: SYS#4909
Depends: libosmocore.git Change-Id If48f412c32e8e5a3e604a78d12b74787a4786374
Change-Id: Ib07c9d23026332a207d4b7a0f7b4e76c0094e379
2021-01-13 17:14:09 +01:00
Neels Hofmeyr 91a202d488 neighbor config: allow re-using ARFCN+BSIC pairs
Fix neighbor config to match OsmoBSC manual: implement the plan for neighbor
configuration that was so far only described in the manual without actually
being in operation.

This first allows re-using ARFCN+BSIC pairs in and across BSS.

So far the handover_start() code always looked for handover target cells across
*all* local cells, even if they were not listed as neighbors to a source cell.
Imply all cells as neighbors only as long as there are no explicit neighbors
configured. As soon as the first 'neighbor' line appears in a 'bts' config,
only the listed neighbors are regarded as handover target cells. (The
'neighbor-list' commands are not related to this, only the relatively new
'neighbor (bts|lac|cgi|...)' commands affect actual handover procedures.)

TTCN3 tests TC_ho_neighbor_config_1 thru _7 play through the various aspects of
neighbor configuration: both the legacy implicit all-cells-are-neighbors as
well as allowing only explicit neighbors by config.

Related: OS#4056
Related: osmo-ttcn3-hacks Ia4ba0e75abd3d45a3422b2525e5f938cdc5a04cc
Change-Id: I29bca59ab232eddc74e0d4698efb9c9992443983
2019-08-13 23:47:23 +02:00
Neels Hofmeyr 431e085736 inter-BSC HO: neighbor_ident API: drop 9bit BSIC
9-bit BSIC exist in the 3GPP specs, but we don't use them anywhere. Rather
remove that choice from the API and UI.

Change-Id: I29b92f47da2636d3a19f073755f9382fa98f9010
2018-07-28 12:18:23 +02:00
Neels Hofmeyr 19bed23065 inter-BSC HO: add neighbor_ident API to manage neighbor-BSS-cells
Depends: Ia71ba742108b5ff020997bfb612ad5eb30d04fcd (libosmocore)
Change-Id: I0153d7069817fba9146ddc11214de2757d7d37bf
2018-07-28 12:18:23 +02:00