cancel
Showing results for 
Search instead for 
Did you mean: 
cancel
794
Views
0
Helpful
8
Replies

Inbound calls through MGCP controlled FXO, throught CTI RP to CUC Call Handler sends unwanted DTMF digits

jeffrey.girard
Level 1
Level 1

      Continuting my experimentation and learning in my home lab.  I have replicated what I think is a pretty common commercial setup.  CUCM 9 with a couple of IP Phones.  I have a router functioning as an MGCP gateway with both FXO port and an E1 trunk.  I have another router  functioning as the PSTN and it has the other end of the E1 trunk and it also has the FNS ports.  I have CUC  9 configured with some VM boxes for the IP phones.

I have configured the MGCP controlled FXO port to PLAR to a CTI Route Point and that CTI RP is set to CFA to VM.  I have configured the E1 trunk with zero significant digits and to prepend the digits that will send the call to the CTI RP as well.

I have configured a System Call Handler and have recorded a personal greeting.

So, if I dial the CTI RP DN from an IP phone, I get the personal greeting as expected.  If I dial the appropriate POTS number from the PSTN analog phones, the call traverses the E1 (as expected) as I get the personal greeting - as expected.  All is well.

Here is the problem:  If I dial the appropriate POTS number from the PSTN analog phones, the FXO port answers, the call is forwarded to the CUC, but I dont get the personal greeting.  Instead, I get the first half second of the opening greeting (I can hear my recorded self start to inhale before I speak).  I can also hear (faintly) DTMF tones being passed.  Then, I get the error message "I did not recognize that as a valid entry".  After that, my recored personal greeting starts.

For debugging, I downloaded and installed the Connection Remote Port Status Monitor and watched the output of both a good call and a bad call.  What I found in the output is that the Remote Port Status Monitor is receiving my dialed DTMF digits.  Since I have not configured them as legal user input values, that is why I am getting the error message.  After the error message play, CUC sends the call back to the system call handler personal greeting.

So, I know what is happening and I now why CUC is responding the way that it is.  What I do not know, and what Im hoping someone can help me with - is why are my dialed DTMF digits being received by the CUC?

FXO and FXS port are both configured to be loopstart with no battery-reversal answer.

As this is a lab, I can provide any debugs, sh run, or screenshots needed.

Hope someone can assist me in my learning

Jeff  

8 Replies 8

basyadav
Cisco Employee
Cisco Employee

Hi Jeffrey

Sorry i got a bit confused after reading through your query. You mentioned when calling the CTI Route Point from "Internal IP Phone" and and from "PSTN via E1", you hear the recorded prompt on UC CH and all works well. Correct?

When you via from "PSTN via FXO", you don't hear the personal greeting. Correct? Is this the issue or you pressing DTMF's and they are getting pass through to CUC via FXO is an issue?

- Basant

Basyadav -

     Thanks for responding and Im sorry for the confusion.

     Im not pressing DTMF (except for pressing 8356300 to place the initial call). 

     In the Connection Remote Port Status Monitor I can see the exact same DTMF digits being received by the voicemail port.  This is what is causing the error.

     What I am trying to figure out is - why are those DTMF tones/digits being received by the VM port / Call Handler?  Should they not have been consumed by the PSTN FXS port as a POTS dial peer?  My CTI RP is directory number 7000 and the voicemail pilot is 8000 - so they are not enought close.

      I thought perhaps I had a bad analog phone (it was an old one) so I went out and bought a new one and put it on my lab setup.  Same result.

Jeff

Np jeff..It's a weird behavior though. Could you share the GW Configuration and highlight the FXO port receiving the call from PSTN as well. Also, is it possible to get a CUCM trace for this call as well.

- Basant

Basant -

     I can provide but not until Tue evening US east coast time.  Im currently at my client location and will not return to my home lab until then.

     What CUCM traces do you want me to capture (Im assuming from RTMT)

Sure Jeff...I just need the Detailed Traces of "Call Manager service" from all servers in the cluster.

- Basant

Basant -

     Files attached.  Call is originated by a PSTN phone (DN = 835-0406) and it dials 835-6300.  All FXO ports are configured the same (they just have different "make believe" PSTN numbers.  However, the specific FXO port that answers the call from the PSTN is voice port 0/0/0.

The FXO is set to PLAR to a CTI RP of 7000.  That CTI RP is set to CFA to voicemail and the VM pilot number is 8000.

Hope this helps.  I took a look at the trace files and could not make heads nor tails of them. 

I also included the PSTN config in case you wanted to see that

Jeff               

jeffrey.girard
Level 1
Level 1

Basant -

     Thank you for your time and willingness to help me out - but I figured out my own problem.  On my FXS dial-peer that send the call out to the FXO, I had included forward-digits all.  Since the FXO does not need the digits/DTMF, it was just fowarding the DTMF tones as the call progressed to my call handler.  I removed the foward-digits all and now its working correctly

Jeff

Aaha...Good find Jeff!!

Thanks for sharing the solution.

- Basant

Getting Started

Find answers to your questions by entering keywords or phrases in the Search bar above. New here? Use these resources to familiarize yourself with the community: