Connecting an ISDN telephone

Hi,

I am newbie to the world of ISDN. I have some experience with SIP. I am attempting to connecting an ISDN phone to a B400P card. The mISDN version is 1.1.7 and Asterisk is 1.4.16.

Your document excellently describes the steps to follow to install and configure the card. The phone itself is connected to the card port 1 and is powered from the card. This is working fine. The 4 ports on the back of the card are all flashing red. They all remain flashing red even after the phone is connected.

I have noticed that in Asterisk the port status is DOWN. I have tried many variations and the only way to get the port status to remain up is to configure the mISDN.conf and include in the port section 'capi="yes"'. Without this they will always remain down.

I have enabled debugging on Asterisk and when I disconnect the phone it recognises this but when I attempt to dial a phone number nothing happens and nothing gets displayed in the log file.

Can anyone help me with this?

hello, rcashell:
have you check the jumper for NT mode and power supply on the card? mISDN has a tool for debugging, you can try that.
Regards!
James.zhu

Hi James,

thank you for the tip. I have a quick question about my possible configuration. If I am connecting a phone directly into the openvox card do I need a cross over cable for this or is a regular RJ45 sufficient?

I tried the ISDN debug tool but it is not giving any output so I can only guess that the problem is somewhere with my hardware setup.

Hi James,

I have another question, the card has been set to NT mode with power enabled and power cable added. However, after reading some literature (and this is where it is confusing) should I configure the adapter in mISDN.conf as TE or NT?

hello, Rcashell:
You use RJ45 connector to connect with your ISDN phone. there are two files you have to edit. mISDN.conf and misdn.conf. the two files work as zaptel.conf and zapata.conf. please check the mISDN.conf under /etc, set it as NT mode, if the port connects with ISDN phone. otherwise, if it is TE mode. you also need to check the /etc/asterisk/misdn.conf as well, make sure context can match the context in extensions.conf . good luck!
James.zhu

I have made some inroads with this but I still cannot get this to work. I have configured the mISDN.conf configuration file indicating that the ports should be nt_ptp. I start the mISDN processes and when I enable the mISDNdebugtool I see some output when I pick up the handset.

# mISDNdebugtool -v
Received packet from 127.0.0.1:33264 (vers:1 protocol:NT type:D_RX id:00000100 plen:
1199882616.814256000: fc ff 03 0f 93 c4 01 ff

Received packet from 127.0.0.1:33264 (vers:1 protocol:NT type:D_RX id:00000100 plen:
1199882618.862256000: fc ff 03 0f 0e c9 01 ff

Received packet from 127.0.0.1:33264 (vers:1 protocol:NT type:D_RX id:00000100 plen:
1199882620.894256000: fc ff 03 0f 89 ce 01 ff

This appears to be working fine. Then I start asterisk and when I pick up the receiver I get no dial tone. When I issue misdn show stacks I get the following output:

CLI> misdn show stacks
BEGIN STACK_LIST:
* Port 1 Type NT Prot. PTP L2Link DOWN L1Link:UP Blocked:0 Debug:4
* Port 2 Type NT Prot. PTP L2Link DOWN L1Link:DOWN Blocked:0 Debug:4
* Port 3 Type NT Prot. PTP L2Link DOWN L1Link:DOWN Blocked:0 Debug:4
* Port 4 Type NT Prot. PTP L2Link DOWN L1Link:DOWN Blocked:0 Debug:4

For some reason the L1Link is up but the L2Link remains down. I have read lots in the last week on this but I cannot find any good articles that explain in detail ISDN and its configuration. Can anyone help me with both finding good articles on the subject of ISDN and also on helping me resolve this issue?

Many thanks