One-Way Audio

I'm observing one-way audio here with the following configuration:

- Asterisk 1.8.4.4 on ubuntu
- Kernel 3.2.0-18 from ubuntu
- mISDN, mISDNuser, LCR from yesterday (GIT mISDN.eu)
- made sure to remove old mISDN from installed kernel in /lib/modules,
  installed new modules and ran depmod, so I'm quite sure we're running
  correct version
- HFCmulti card (I can dig out the info which card if needed)

Both, call *from* a sip-phone into asterisk out via ISDN as well as an
incoming call from isdn to sip phone experience one-way audio: The ISDN
side can hear everything from the SIP phone but not vice-versa.

When we bridge two isdn calls via Asterisk, we get two-way audio, in
that case both isdn users can hear each other. Seems in this case audio
is bridged *in the ISDN card* am I right in this asumption?

An strace of asterisk with the one-way-audio setup shows us that
asterisk is polling a file descriptor but never receiving anything while
it copies lots of data in the other direction.

This doesn't seem to be a firewall issue, SDB setup looks ok, we just
get only RTCP/RTP packets from the sip phone to asterisk but not
vice-versa. This is probably because asterisk doesn't get anything from
isdn.

Any idea how to further debug this?

Ralf
-- 
Ralf Schlatterbeck             email: [email protected]