Choppy audio and dropped packets for MeetMe

Asterisk Asterisk Support
1

Hey guys,

I have a MeetMe conference room hosted on one of my PBXs. When I call into that conference room from a phone on another PBX (over IAX), the voice of the person calling in remotely is very choppy, but voices in the other direction are fine. I.e., the remote caller sounds bad to everybody else, but everybody else sounds fine to him or her, unidirectional choppiness. What’s strange is that if I make a normal call over IAX everything works fine, no choppiness.

The output of “iax2 show netstats” seems to show that there is packet loss during a remote call-in with MeetMe but none without:

pbx-2*CLI> iax2 show netstats -------- LOCAL --------------------- -------- REMOTE -------------------- Channel RTT Jit Del Lost % Drop OOO Kpkts Jit Del Lost % Drop OOO Kpkts FirstMsg LastMsg IAX2/conf-14 1000 151 191 19 18 0 2 0 0 0 0 0 0 0 0 Rx:NEW Tx:ACK 1 active IAX channel pbx-2*CLI>

pbx-2*CLI> iax2 show netstats -------- LOCAL --------------------- -------- REMOTE -------------------- Channel RTT Jit Del Lost % Drop OOO Kpkts Jit Del Lost % Drop OOO Kpkts FirstMsg LastMsg IAX2/priv-2039 1000 0 40 0 0 0 0 0 0 0 0 0 0 0 0 Rx:NEW Tx:ACK 1 active IAX channel pbx-2*CLI>

I thought that it must be a timing issue since it’s only happening in conferences, but I can’t seem to get anywhere on that. I’m using a DAHDI psuedo device on both PBXs, and that seems to be working, but “dahdi” commands from the Asterisk CLI aren’t present. I haven’t found any good resources on how to configure a DAHDI psuedo device in terms of chan_dahdi.conf, etc.

Does this sound familiar to anyone? Any help would be much appreciated, thanks!

2

It’s more than likely a time source issue. Either install a digium card or use something like Sangoma’s VoiceTime USB module. If Dahdi commands aren’t showing, it’s not running. You need to resolve that first.

This is what I get on my system running the command below, which shows the dummy driver installed.

dahdi show status
Description Alarms IRQ bpviol CRC4 Fra Codi Options LBO
DAHDI_DUMMY/1 (source: Linux26) 1 UNCONFI 0 0 0 CAS Unk YEL 0 db (CSU)/0-133 feet (DSX-1)

You might want to take a look at packtpub.com/asterisk-1-4-t … 08099c5ceh (shameless plug) which has a chapter on Dahdi

Regards

3

Thanks for the response, I’ll see if I can sort out the DAHDI issue first, then perhaps go for an external time source.

4

The option for chan_dahdi is XXX in the make menuconfig for Asterisk… that could be part of the issue. Is chan_dahdi necessary for just the pseudo dummy device?

5

I can’t, for the life of me, figure out why the chan_dahdi driver under menuselect is Xed out.

I tried running “./configure --with-dahdi --with-tonezone” to force the routine to recognize that I want DAHDI support, it errors out on this:

configure: *** configure: *** The TONEZONE installation appears to be missing or broken. configure: *** Either correct the installation, or run configure configure: *** including --without-tonezone.

The config.log shows this:

configure:38223: checking for tone_zone_find_by_num in -ltonezone configure:38258: gcc -o conftest -g -O2 conftest.c -ltonezone -lm >&5 /usr/bin/ld: cannot find -ltonezone collect2: ld returned 1 exit status

However, tonezone is present on the filesystem:

[root@pbx asterisk-1.6.2.0]# locate tonezone /usr/lib/libtonezone.so.1 /usr/lib/libtonezone.so.1.0 /usr/lib64/libtonezone.so.1 /usr/lib64/libtonezone.so.1.0 [root@pbx asterisk-1.6.2.0]#

If I remove the “–with-tonezone” option, the configure routine completes successfully, but chan_dahdi is still unavailable in menuselect and not compiled during make.

I’ve been tearing my hair out at this… any guidance would be appreciated.