Failed to decode CallerID

I cannot get the Caller ID from any of my incoming calls from PSTN.

I always get the following logs:
– Starting simple switch on 'DAHDI/1-1’
ERROR[14233]: callerid.c:564 callerid_feed: No start bit found in fsk data.
WARNING[14233]: chan_dahdi.c:7895 ss_thread: Failed to decode CallerID on channel 'DAHDI/1-1’
WARNING[14233]: chan_dahdi.c:8000 ss_thread: CallerID returned with error on channel ‘DAHDI/1-1’
– Executing [s@from-zaptel:1] NoOp(“DAHDI/1-1”, "Entering from-zaptel with DID == ") in new stack

I’m using Elastix 1.6.2-27, Asterisk 1.4.36, Dahdi My digium card is an AEX808E.

I’m in the Philippines and my provider is PLDT. They’re using dtmf to pass the callerid after the first ring.

These are my configuration files.

- chan_dahdi.conf


- modprobe.d/dahdi.conf
options wctdm24xxp latency=6 opermode=PHILIPPINES fwringdetect=1 ringdebounce=1219

I record the incoming call using dahdi_monitor. When I listened to it, I heard the dtmf tones(callerid) but it’s incomplete. It always caught only 2 to 4 numbers. The format of the callerid is “D(telephone number)C”.

Does anyone know how to make the PLDT callerid work in asterisk?


Please contact Digium’s Support department directly:



I already contacted the digium support and tried their suggestions but it didn’t work.

Sometimes the error doesn’t appear and I hear complete callerid when I listened to the recorded incoming call using dahdi_monitor but the callerid still doesn’t display.

Is there something I need to change on the Asterisk side?

How did you solve his problem.

newbie1234: In your other thread, you are claiming that your intercom sends caller ID using DTMF. The symptoms in this thread cannot happen when using DTMF for caller IDs, so any solution is irrelevant to your system.

If your system doesn’t use DTMF for caller ID, you need to specify that part of the configuration first, before you worry about intermittent faults.

dwyn_krystoff: I was trying to make sense of david55’s comment to newbie1234 about dtmf callerid not applying when I noticed something odd in your settings that you may need to take up with the Elastix community.

Your configuration says to use DTMF (cidsignalling=dtmf) yet your log message indicates it’s looking for FSK data (“No start bit found in fsk data”). Somehow the actual configuration and the config files are out of sync (or I’m confused…).

It was the reference to start bits which made me conclude that it was relevant.