This patch adds the voice muxer. You can use this to batch RTP
traffic to reduce bandwidth comsuption. Basically, osmux transforms
RTP flows to a compact batch format, that is later on decompacted
to its original form. Port UDP/1984 is used for the muxer traffic
between osmo-bsc_nat and osmo-bsc_mgcp (in the BSC side). This
feature depends on libosmo-netif, which contains the osmux core
support.
Osmux is requested on-demand via the MGCP CRCX/MDCX messages (using
the vendor-specific extension X-Osmux: on) coming from the BSC-NAT,
so you can selectively enable osmux per BSC from one the bsc-nat.cfg
file, so we have a centralized point to enable/disable osmux.
First thing you need to do is to accept requests to use Osmux,
this can be done from VTY interface of osmo-bsc_nat and
osmo-bsc_mgcp by adding the following line:
mgcp
...
osmux on
osmux batch-factor 4
This just initializes the osmux engine. You still have to specify
what BSC uses osmux from osmo-bsc_nat configuration file:
...
bsc 1
osmux on
bsc 2
...
bsc 3
osmux on
In this case, bsc 1 and 3 should use osmux if possible, bsc 2 does
not have osmux enabled.
Thus, you can selectively enable osmux depending on the BSC, and
we have a centralized point for configuration from the bsc-nat to
enable osmux on demand, as suggested by Holger.
At this moment, this patch contains heavy debug logging for each
RTP packet that can be removed later to save cycles.
The RTP ssrc/seqnum/timestamp is randomly allocated for each MDCX that
is received to configure an endpoint.
The filtering architecture already allowed to specify a reject
reason but this has not been used for the access-lists. Extend
the access-list to include a reject reason and extend the test
case to honor it.
So far the payload type used in RTP streams has been taken from the
trunk configuration in NAT mode.
This patch changes the implementation to use the payload type
announced in the SDP part of MGCP messages and responses. SDP
descriptions more than one m=audio line are not yet supported
properly (always the last one is taken).
Ticket: OW#466
Sponsored-by: On-Waves ehf
* The post-routing is applied after the first re-writing. To do this
the new number is copied back into the called data structure.
* Add a testcase that goes from 0172 to 0049 and then back to 0049
using the post rule with a table lookup.
* Increase the rewritten rule to five digits (this is the easiest
for the unit test). This will add another 40kb to the runtime size.
* Create a unit test that tests adding and removing the prefix rules.
* Use the regexp match to replace from one package
Find the Cell Identifier from the Complete Layer3 Information and
store it for future reference. We could begin to verify that the
LAC/CI used really belongs to the BSC.
The name sccp_connection is used in the osmo-sccp code, sccp_connections
was used in the NAT for tracking a sccp_connection. Rename it so it is
obvious that the struct belongs to the nat.
The rename was done with sed:
$ sed -i s,"struct sccp_connections","struct nat_sccp_connection",g \
include/openbsc/*.h src/osmo-bsc_nat/* tests/*/*
Prepend the international number with a '+' and then do the normal
re-writing on it. There are a couple of ways to handle this:
\+([0-9]), \+[0-9][0-9]([0-9]), \+49([0-9])
Add a test case for the international re-write based on an already
internationalized number.
We want to send a TRAP with the MGCP statistics from the NAT and
the connected BSC. The BSC endpoint can be either released because
of a DLCX from the MGCP CallAgent or the SCCP Connection release on
the A-link.
This is why we need to queue the statistics when the deleting the
endpoint on the BSC. The processing is continued once the response
arrives. This code assumes that the response of the DLCX will be sent
by the remote side. The current amount of outstanding responses can be
seen on the VTY. This assumption is based on the fact that the BSC has
already responded to the CRCX and maybe to the MDCX.
The MGCP RFC is bended to prefix the transaction identifier with "nat-"
to easily detect the response and hand it to the handler. This will
then parse the response and generate the TRAP. The current version is
v1. We assume that the transaction space is big enough and we will
not re-assign the transaction identifier too early.
In preparation for another kind of black-list allow the filter code
to decide how the connection should be rejected. Introduce a new struct
that will carry the reject causes for certain operations.
Introduce number rewriting of SMS-SUBMIT. Introduce a new list,
move code around to help with finding a new number, somehow the
number encoding for TP-DA is borked, 03.40 references 04.11 but
the length appears to be strlen(number) without taken the type
field into account.
Match IMSI and destination address against a set of entries, if it
is matching the header will be modified and no sender report will be
requested. Change the test case to request the sender report and then
verify that this bit is reset to 0.
Move the regexp parsing code from the NAT to libcommon as it will
be used by the NAT and BSC code. This also adds the #include <regex.h>
include to gsm_data. This header should be split up.
The idea that MCC and MNC is enough to classify a subscriber
turns out to be wrong. Certain operatos license a number range
of IMSIs to others. When we see a '^' in the MCC field we treat
it as a regexp. The code now turns the MCC/MNC into a regexp
for the IMSI. It is not using extended POSIX regexp to match
the behavior of the access list.
Use the libosmocore code to ignore certain signals by
default (e.g. SIGHUP, SIGPIPE) and use the new code to
create a default stderr logging target and initialize
it properly.
The current code tries to find _one_ bsc for a paging message
and then continues. The new code will try to find multiple BSCs
for each LAC. This is done in preparation of having two BSCs
handle the same LAC. This code right now is O(m*n) but it will
be worse once paging groups are landed.
The code to test the function was reduced to just test the lac
lookup code as the other part can not be tested in a standalone
setup anymore.
In 136f453dd2, I forgot to update
the new header path in the test/bsc-nat files (this happened to
me because I forgot to configured openBSC without --enable-nat).
On a classic BSC we have 32 channels but one is reserved for
signalling. Make sure that we are not assigning 0x1f as we
assume that this is the signalling channel. This means that
from 32 possible voice channels we are only going to use 30
as we are already not using the 0x0.
Allocate the status for an endpoint dynamically. We will support
BSCs with different amount of multiplexes and need to have this
flexibility in the future. Add the proper null checks to the
current users of this code.
bsc_init.c was a big mess even only for two supported BTS models,
so before adding more BTS types, this needs a cleanup.
All the BTS specific code from bsc_init.c has now moved into
bts_{siemens_bs11,ipaccess_nanobts}.c
This has required that input_event() and nm_state_event() get both
converted to proper libosmocore signals instead of referencing external
symbols.
The reason for this is quite simple: We want to make sure anyone
running a customized version of OpenBSC to operate a network will
have to release all custom modifiations to the source code.
Extract the IMSI from the first message as well and safe it
in the connection structure. The problem is that we do not
have this structure at this point, so we will allocate the
imsi as child of the bsc_connection and then move/steal it.
Currently it is not is not easily possible to disable
everyone and then only allow certain SIMs. By changing
the order we can do:
access-list imsi-deny only-something ^[0-9]*$
access-list imsi-allow only-something ^123[0-9]*$
and still keep the usecase of only forbidding certain
SIMs on certain LACs. Adjust test case, test that the
other cases are still functional.
Make it possible that one BSC is serving multiple
cells. Introduce a list of lacs, add functions to
manipulate the lists. The current test cases for
paging by lac continue to work.
Pablo Neira Ayuso
Harald Welte