${CALLERID(RDNIS)} not able to get redirected dialled number in asterisk

Question

I have this situation where I have 2 numbers say A and B which is forwarded to same DID number so the issue is that I want to identify if the call is forwarded from A or B when the caller calls in to specific number.

I have researched a bit and found about ${CALLERID(rdnis)} in asterisk but when am trying to use it gives a blank output. I also tried the DumpChan() command it also gave a (N/A) for rdnis.

Is there any way I can get to know in my dialplan that call is forwarded from A or B ?

I dont have sip my line is normal PSTN. The problem is that the number mentioned in the question A and B are mobile number which are forwarded to DID number and I can only control the code after the DID is called but I cannot identify through which number A or B the call is forwarded on DID.

Answer 1

If your number is sip, you can do

asterisk -r
sip set debug on

After that call in. If you see forwarded number in packet, you can try get it using SIP_HEADER function. If there is no any difference in two calls, you can't recognize did and better use cheap voip did for second number.