James Zhang [Tue, 3 Apr 2012 15:23:49 +0000 (11:23 -0400)]
freetdm: Clean up SS7 native bridge code to separate the call control, queuing and
resource-cleanup responsibilities clearly between the 2 channels involved in the bridge
- Each channel is responsible for clearning its own peer_data and event queue
at the end of the call (when moving to DOWN state)
- Each channel dequeues messages only from its own queue and enqueues messages
in the peer's queue, with the only exception being messages received before
the bridge is stablished (IAM for sure and possible SAM messages) because
if the bridge is not yet stablished the messages must be queued by the channel
in its own queue temporarily until the bridge is ready
- When the bridge is ready it is the responsibility of the incoming channel to
move the messages that stored temporarily in its own queue to the bridged peer queue
- During hangup, each channel is responsible for moving itself to DOWN. The procedure
however differs slightly depending on the hangup conditions
If the user requests hangup (ie, FreeSWITCH) the request will be noted by setting the
FTDM_CHANNEL_USER_HANGUP flag but will not be processed yet because call control is
driven only by the link messages (so no hangup from ESL or command line allowed)
When REL message comes, the channel receiving it must move to TERMINATING state and:
- If the user has not hangup yet (FTDM_CHANNEL_USER_HANGUP flag not set) then
notify the user via SIGEVENT_STOP and wait for the user to move to HANGUP
state by calling ftdm_channel_call_hangup() before sending RLC
- If the user did hangup already (FTDM_CHANNEL_USER_HANGUP flag is set) then
skip user notification and move to HANGUP state directly where the RLC message
will be sent
- On HANGUP state the RLC is sent and the channel is moved to DOWN, final state
The peer channel will forward the REL message and wait for RLC from the network, when
RLC is received the channel can move straight to DOWN itself because the peer channel
is completing its own shutdown procedure when it received the REL message
Viktor Krikun [Tue, 20 Sep 2011 20:24:57 +0000 (20:24 +0000)]
Move ZRTP_SRTP_HASH_SHA1
ZRTP_SRTP_HASH_SHA1 was moved from public zrtp_hash_id_t to the
private srtp implementation. HMAC SHA1 constant was also renamed to
ZRTP_SRTP_HASH_HMAC_SHA1 in order to raise an error if the user tries
to use an old ZRTP_SRTP_HASH_SHA1 constant in a ZRTP session
configuration.
James Zhang [Fri, 30 Mar 2012 20:50:00 +0000 (16:50 -0400)]
freetdm: Adding condition to parse sip headers only for non-freetdm channels.
This fixes an issue where ss7 native bridge was accidentally enabled
any time two freetdm channels were bridged regardless of the freetdm_native_sigbridge
variable value.
Stefan Knoblich [Wed, 28 Mar 2012 21:09:42 +0000 (23:09 +0200)]
ftmod_misdn: More reworking of b-channel audio tx handling.
Use the amount of audio data received in misdn_read() to determine how many
bytes we need to send to the b-channel (= how much free space is left
in the b-channel tx queue). (This is how libosmo-abis and LCR handle it too.)
A pipe is used as a poll()-able audio tx buffer (filled in misdn_write()):
FTDM_WRITE wait requests are currently poll()-ed on the input side of the pipe,
whereas FTDM_READ and _EVENT requests are poll()-ed on the b-channel socket itself.
For every N-bytes of audio data read from the b-channel in misdn_read(),
we try to get as much out of the tx pipe, convert it into the ISDN_P_B_RAW
format and send it to the b-channel socket.
If there's less than N-bytes left in the pipe, we fill the remaining buffer
with silence to avoid buffer underflows.
B-Channel handling overview:
- misdn_wait(FTDM_WRITE) on audio pipe
- misdn_write() put audio data into pipe
- misdn_wait(FTDM_READ) for next incoming mISDN
message on b-channel socket
- misdn_read() handle mISDN event, for PH_DATA_IND:
- Write data into channel buffer and convert
to a/u-law using misdn_convert_audio_bits()
- Try to fetch N-bytes from audio pipe
- If not enough bytes in pipe: fill remaining space with silence
- Convert audio to raw format
- Send to b-channel (PH_DATA_REQ)
Known problems / bugs / further investigation:
1. Bridge aborted by "Write Buffer 0 bytes Failed!" error from switch_core_io.c.
This is "fixed" by _not_ setting the b-channel sockfd to non-blocking mode.
2. Audio glitches (maybe caused by FTDM_WRITE misdn_wait() handling or blocking I/O on sockfd?)
3. misdn_read() EBUSY error messages from sending data to b-channel sockfd after enabling channel.
Signed-off-by: Stefan Knoblich <stkn@openisdn.net>
projects / thirdparty / freeswitch.git / log
