Commit Graph

14 Commits

Author SHA1 Message Date
Neels Hofmeyr 909e972787 HO: Implement load based handover, as handover_decision_2.c
Change-Id: Ie597eae82722baf32546331e443dd9d94f1f25e6
2018-02-19 17:11:47 +01:00
Harald Welte 51e4bf3298 Permit set of multiple different A5 ciphers
So far, the administrator had to pick one particular cipher which
would then be used throughout all subscribers/phones. This is a bit
impractical, as e.g. not all phones support A5/3.  Extend the VTY
command syntax in a backwards-compatible way to permit for multiple
ciphers.

The bit-mask of permitted ciphers from the MSC (sent in ASSIGNMENT
COMMAND) is intersected with the vty-configured mask a the BSC.
Finally, the best (highest) possible cipher is chosen.

Change-Id: I1d1c8131855bcab2392b4f27f6216bdb2fae10e0
Closes: OS#2461
2018-02-19 11:43:07 +01:00
Neels Hofmeyr d23ce86c25 drop libcommon-cs completely
Change-Id: I07d4a48af3154ee4d904686f230a51b8b8a94ff9
2018-02-14 12:55:45 +01:00
Neels Hofmeyr d85e4cb711 gsm_network: drop unused trans_list
Change-Id: I7910ce8098d5431e41409bf09429ae4221efb360
2018-02-14 12:55:45 +01:00
Neels Hofmeyr ab1b381d1b libcommon-cs: move gsm_network_init() into bsc_network_init()
Some part of the network init was common between libbsc and libmsc in the old
openbsc.git repository. Now osmo-bsc.git is independent with its own copy of
the gsm_network initialization. So move it over to libbsc.

Change-Id: I8968787a5f0b078619264f0cb42349a9bc7943af
2018-02-14 12:55:45 +01:00
Stefan Sperling 6cee893a0f Make "waiting indicator" of IMMEDIATE ASSIGN REJECT dynamic.
The IMMEDIATE ASSIGN REJECT message contains a wait indicator which
tells an MS requesting a channel to wait for a specified amount of
time before trying to request a channel again, i.e. the wait indicator
controls the T3122 timeout value in the MS.

Previously, the wait indicator was fixed to 10 seconds.
This is not sufficient if there are a lot of MS requesting channels
because the MS will retry too soon. Instead of using a fixed value,
maintain a dynamic wait indicator value based on average channel load.

The load (used vs. available channels on a BTS) is sampled once per
second, and once 8 samples have been collected we update a BTS-specific
T3122 wait indicator based on the measured load.

While the wait indicator could go up to 255 seconds, this initial
implementation keeps it in the range from 10 to 128 seconds.

Further experimentation and testing will show whether higher wait
indicator values are desirable, if the sampling rate needs to change,
or if the function mapping the load measurement to a wait indicator
value should change (currently we map the load average linearly into
the range [10, 128] inclusive).

Change-Id: I57e38f6d6ba3b23cc6e1f9520b90261dbb1f1cec
Related: OS#2592
2018-02-05 13:58:17 +01:00
Neels Hofmeyr e25018b8c1 HO prep: introduce per-BTS handover config, with defaults on net node
It is desirable to allow configuring handover for each individual network cell.
At the same time, it is desirable to set global defaults.

Treat the 'network' node handover parameters as global defaults, add another
set of parameters for each individual BTS.

This raises questions on how the 'network' node should affect the individual
BTS. The simplistic solution would have been: on creating a BTS in the config,
just copy the current defaults; with serious drawbacks:
- tweaking any parameter in the telnet VTY on network node will never affect
  any running BTS.
- network node defaults *must* be issued before the bts sections in the config
  file.
- when writing a config back to file, we would copy all net node defaults to
  each BTS node, making the network node configs pointless.

Instead, add a handover_cfg API that tracks whether a given node has a value
set or not. A bts node ho_cfg gets a pointer to the network node config and
returns those values if locally unset. If no value is set on any node, use the
"factory" defaults, which are hardcoded in the API. Only write back exactly
those config items that were actually issued in a config file / on the telnet
VTY. (ho_cfg API wise, we could trivially add another ho_cfg level per TRX if
we so desire in the future.)

Implement ho parameters as an opaque config struct with getters and setters to
ensure the tracking is always heeded. Opaqueness dictates allocating instead of
direct embedding in gsm_network and gsm_bts structs, ctx is gsm_net / bts.

This is 100% backwards compatible to
old configs.
- No VTY command syntax changes (only the online help).
- If a 'bts' sets nothing, it will use the 'network' defaults.
- The 'show network' output only changes in presence of individual BTS configs.

On 'show network', say "Handover: On|Off" as before, iff all BTS reflect
identical behavior. Otherwise, output BTS counts of handover being enabled or
not.

Use the same set of VTY commands (same VTY cmd syntax as before) on network and
BTS nodes, i.e. don't duplicate VTY code. From the current vty->node, figure
out which ho_cfg to modify.

For linking, add handover_cfg.c (the value API) in libcommon, while the
handover_vty.c is in libbsc. This is mainly because some utility programs use
gsm_network and hence suck in the ho stuff, but don't need the VTY commands.

Review the VTY online help strings.

Add VTY transcript test for handover options, testing config propagation from
network to bts nodes, 'show network' output and VTY online help strings.
(Needs recent addition of '... !' wildcard to osmo_interact_common.py.)

I considered leaving parts of this more readable, but in the end decided for
heavy use of macros to define and declare the API, because more values will be
added in upcoming patches and I want to prevent myself from messing them up.

Inspired-by: jolly/new_handover branch, which moves the config to 'bts' level
Depends: I7c1ebb2e7f059047903a53de26a0ec1ce7fa9b98 (osmo-python-tests)
Change-Id: I79d35f6d3c0fbee67904378ad7f216df34fde79a
2018-01-19 16:03:16 +01:00
Harald Welte c499e5c62e Remove bogus vty config for LU reject cause
The LU reject cause (like anything MM related) is under control of
OsmoMSC, not BSC.

Change-Id: I559ae31d67726845c9699c8b6127e21c6f63ace6
2017-12-19 17:53:14 +00:00
Harald Welte d9956d91ba Remove dead code left over from NITB split
There still is a lot of dead code that we inherited from the NITB
days, let's remove more of it.

libtrau will be re-introduced as part of osmo-mgw later.

Change-Id: I8e0af56a158f25a4f1384d667c03eb20e72df5b8
2017-12-19 17:53:13 +00:00
Neels Hofmeyr c01647914b move include/openbsc to include/osmocom/bsc
Change-Id: I39e7b882caa98334636d19ccd104fd83d07d5055
2017-09-06 16:26:13 +02:00
Neels Hofmeyr 7b656884cf split off osmo-bsc: remove files, apply build
Change-Id: I64d84c52f6e38e98144eb9be8f0ab82e0e1f6cca
2017-08-30 14:11:25 +02:00
Harald Welte a0d324b3d0 GSM timers: User reasonable defaults; don't save if equal default
A number of the GSM timers (including T3109) had no reasonable
default values if not specified in the VTY / config file.  Together
with unconditional writing to the config file, this created
config files with a persistent setting for important timers as '0'.

To make things worse, many of our example cofig files suffered from the
same problem.

Let's avoid this from happening by
* having reasonable defaults if nothing specified in the config file
* conditionally savingg timers only if they differ from default
* reject any timer values that state zero during start-up (see previous
  commit)

Change-Id: Iaac0bfca423852b61d8b9eb1438157ef00d0d8c8
Closes: OS#2380
2017-08-27 03:52:46 +02:00
Harald Welte ed208de125 check for missing result of rate_ctr_group_alloc()
In case the counter group allocation fails, we must handle this
gracefully and fail the allocation of the parent object, too.

RelateD: OS#2361
Change-Id: I7dad4a4d52fe05f6b990359841b4408df5990e21
2017-08-27 03:52:45 +02:00
Neels Hofmeyr 218e4b4aa0 move openbsc/* to repos root
This is the first step in creating this repository from the legacy openbsc.git.

Like all other Osmocom repositories, keep the autoconf and automake files in
the repository root. openbsc.git has been the sole exception, which ends now.

Change-Id: I9c6f2a448d9cb1cc088cf1cf6918b69d7e69b4e7
2017-08-27 03:52:43 +02:00