Hi. I have an ASUS WL-HDD 2.5 running OpenWRT WhiteRussian RC4 and asterisk 1.0.7 (from the latest stable package) for some time now. After a lot of fuss (http://forum.openwrt.org/viewtopic.php?pid=23566) I got the ASUS to talk to a USB ISDN adapter, so I am now happily routing calls from ISDN to my 2 Linksys PAP2-NA's (4 SIP lines). I'd like to share my findings here and ask for some advice from the asterisk gurus...
First of all, I use a very small modules.conf:
autoload = no
load => res_features.so ; Call Parking Resource
load => res_musiconhold.so ; Music On Hold Resource
load => chan_sip.so ; Session Initiation Protocol (SIP)
load => chan_modem.so
load => codec_a_mu.so ; A-law and Mulaw direct Coder/Decoder
load => codec_alaw.so ; A-law Coder/Decoder
load => codec_ulaw.so ; Mu-law Coder/Decoder
load => format_pcm.so ; Raw uLaw 8khz Audio support (PCM)
load => format_pcm_alaw.so ; Raw aLaw 8khz PCM Audio support
load => format_sln.so ; Raw Signed Linear Audio support (SLN)
load => app_dial.so ; Dialing Application
load => app_echo.so ; Simple Echo Application
load => app_macro.so ; Extension Macros
load => app_playback.so ; Trivial Playback Application
load => app_transfer.so ; Transfer
load => pbx_config.so ; Text Extension Configuration
In order to use chan_modem I had to disable any dtmf detection. If asterisk does the dtmf detection the system is rendered unusable and if i4l does the dtmf detection I hear tones when someone speaks too loud on the phone. So, I just set dtmfmode=none in modem.conf.
The WL-HDD has a hard disk, so I installed everything related to asterisk there. Also, because I want the system to stay quiet at nights, I made a package with hdparm and shut down the disk after it's idle for 5 minutes. The only thing that remains in memory is /var/spool/asterisk. For some wierd reason even if I link a subfolder of /var/spool/asterisk (like /var/spool/asterisk/voicemail) to a folder on the disk, asterisk will not let the disk to spin down - the disk will immediately restart. So, at least for now, I just don't use voicemail.
To implement MOH, I converted my mp3's to raw and use a "rawplayer" binary:
while [ 1 ]; do
for name in $@; do
cat $name || exit;
My first dissapointment is that the system can not handle the loading of res_indications.so. I need that module, because when I transfer a line the caller can not hear the extension ringing. There is silence until the new callee picks up the phone. Is there any other way to implement this? If I load the module, the caller can hear the line ring, but the sound quality is awful - unacceptable.
What's more important is that after some hours of usage, I have no outgoing sound on incoming calls. When somebody calls, asterisk rings the phones ok, I can pickup the line and listen, but they can not hear me... Restarting asterisk does not seem to help, so I believe that maybe this has to do with the USB ISDN driver. Restarting the system solves the problem. Could this be related to asterisk?
I wish I could run linux 2.6 on this thing and use the mISDN driver...