Since the packet duration is given in ms with the 'ptime' RTP media
attribute and also with the 'p' MGCP local connection option, the
computation is changed to use this value (if present). The
computation assumes, that there are N complete frames in a packet and
takes into account, that the ptime value possibly had been rounded
towards the next ms value (which is never the case with a frame length
of exact 20ms).
Sponsored-by: On-Waves ehf
This forces the output timing to fulfill
dTS = dSegNo * fixedPacketDuration
where dSegNo = seqNo - lastSeqNo.
If timestamp patching is enabled, the output timestamp will be set
to lastTimestamp + dTS. This kind of relative updating is used to
handle seqNo- and timestamp-wraparounds properly.
The updating of timestamp and SSRC has been separated and the patch
field of mgcp_rtp_state has been renamed to patch_ssrc to reflect
it's semantics more closely. The offset fields are now used always
and will change the corresponding header field if they are != 0.
Ticket: OW#1065
Sponsored-by: On-Waves ehf
Currently the output SSRC is always forced to be the same if SSRC
patching is enabled.
This patch modifies this to optionally restrict the number of SSRC
changes that will be corrected.
Note that the configuration only allows for the 'once' mode and 'off'.
Sponsored-by: On-Waves ehf
The ssrc has been used without respect to proper byte ordering in
mgcp_patch_and_count(). This only affected log messages.
This patch introduces a new variable 'ssrc' that takes the value of
the SSRC in proper byte order.
Sponsored-by: On-Waves ehf
This patch adds a packet_duration field to mgcp_rtp_state which
contains the RTP packet's duration in RTP timestamp units or 0, when
the duration is unknown or not fixed.
Sponsored-by: On-Waves ehf
Currently seq_offset and timestamp_offset are updated on each SSRC
change even when SSRC patching is not allowed.
This patch fixes this by changing mgcp_patch_and_count() to only
update these fields when SSRC patching is allowed.
Sponsored-by: On-Waves ehf
Show old and new SSRC. Move logging command upward to show the values
immediately after the change has been detected and before any fixing
attempt is made.
Sponsored-by: On-Waves ehf
This adds datastructures and a VTY frontend to configure the
different type of RTP header patching: SSRC and timestamp.
Note that timestamp patching is not yet implemented.
Sponsored-by: On-Waves ehf
The tsdelta computation and error detection didn't handle the
intialisation phase properly.
This patches fixes this by skipping the output timing validation
when the SSRCs don't match.
Sponsored-by: On-Waves ehf
The current implementation increments the seqno but does not increment
the RTP timestamp, leading to two identical timestamps following one
after the other.
This patch fixes this by adding the computed tsdelta when the offset
is calulated. In the unlikely case, that a tsdelta hasn't been
computed yet when the SSRC changes, a tsdelta is computed based on
the RTP rate and a RTP packet duration of 20ms (one speech frame per
channel and packet). If the RTP rate is not known, a rate of 8000 is
assumed.
Note that this approach presumes, that the per RTP packet duration
(in samples) is the same for the last two packets of the stream being
replaced (the first one).
Sponsored-by: On-Waves ehf
This patch adds a test case to check, whether RTP timestamps are
generated properly after SSRC changes and whether the error counters
work properly.
Sponsored-by: On-Waves ehf
This patch modifies the patch_and_count() function to check for RTP
timestamp inconsistencies. It basically checks, whether dTS/dSeqNo
remains constant. If this fails, the corresponding counter is
incremented. There are four counter for this: Incoming and outgoing,
each for streams from the BTS and the net.
Note that this approach presumes, that the per RTP packet duration
(in samples) remains the same throughout the entire stream. Changing
the number of speech frames per channel and packet will be detected
as error.
In addition, the VTY command 'show mgcp' is extended by an optional
'stats' to show the counter values, too.
Ticket: OW#964
Sponsored-by: On-Waves ehf
GCC 3.x on PowerPC correctly highlights that the code is fishy.
Re-reading the RFC 3550 shows that we should subtract it and then
we are in the 16bit range. The probation and re-sync code is still
missing.
GCC:
mgcp/mgcp_network.c:200: warning: comparison is always true due to limited range of data type
Use a usec timestamp for the local time. The seconds to usec will
swap over to the lower bits but this appears to be correct. The
CLOCK_MONOTONIC is used to fulfill the RFC 3550 requirement even
if it is a bit slower than the gettimeofday.
Make sure to initialize transit in a way that the first transit
time will be 0. Otherwise the jitter will contain the difference
of the localtime and the remote time.
Calculate the expected packages and packet loss as of RFC 3550.
The values should be clamped but our packet loss counter is 32
bits and not 24 and we should clamp at other values but I am
waiting for some issues first before dealing with that.
This is missing the probation and the dealing with a remote
restart. For the remote restart we will simply write a log
statement as this is unlikely to happen during a call or if
it does happen the call will be taken down by the BSC anyway.
Align the naming inside the mgcp_rtp_state with the naming inside
the 'source' struct of the appendix. Make first_seq_no/base_seq
a uint16_t. This is removing rules for alignments and reduces the
struct from 40 bytes to 36.
Count the received octets. This is encouraged by the MGCP specification.
Use a 32bit counter that is good enough for more than 12 hours of a EFR
call. This limit is good enough for the current configuration.
The RFC 3435 specifies a different formula for calculating the lost
packages. It involves the number of received packages and the delta
of the sequence number.
When adding the "omit RTCP" the method started to return with
a proper return statement.
mgcp_network.c: In function ‘send_to’:
mgcp_network.c:233:1: warning: control reaches end of non-void function [-Wreturn-type]
The ip.access nanoBTS appears to send quite broken NTP timestamps in
the RTCP messages might confuse equipment that uses the sender report
of the BTS. Make it easy to experiment by adding an option to drop RTCP.
libosmogsm is a new library that is distributed in the libosmocore.
Now, openbsc depends on it. This patch gets openbsc with this
change.
This patch also rewrites all include path to the new
osmocom/[gsm|core]
Signed-off-by: Pablo Neira Ayuso <pablo@gnumonks.org>
Jacob Erlbeck
Harald Welte