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DTMF between Siemens PBX & Cisco CUCM




CUCM 7.1

CIsco Unity Connection 7.0

Siemens PBX


Siemens PBX is connected to cisco router using E1 line. This router is configured as h.323 gateway in CUCM. Two way calling between Cisco & Siemens is working fine. If user calls voice mail pilot number from Siemens phone, user gets voice mail prompt. But PIN entered by user from siemens phone is not accepted by Cisco setup.

Is some configuration is required on router or CUCM so that DTMF works between CIsco & Siemens.


Abhas Jain

1 Accepted Solution

Accepted Solutions

change 110 voip to dtmf-relay h245-alpha and see if it works

View solution in original post

4 Replies 4

Cisco Employee
Cisco Employee

You need to check the dialpeer. The siemens pBX is probably connected to a router over isdn or is it IP to the CUCM directly ?Also is the siemens pbx configured in the cucm as a gateway or non gk controlled trunk.


Siemens PBX is connected to router over ISDN. This router is configured as H.323 gateway in CUCM.

There is no IP to IP connectivity between siemens PBX & CUCM.

Below is E1 & dial peer configuration on router:-

controller E1 1/0/0
pri-group timeslots 1-31

interface Serial1/0/0:15
no ip address
no logging event link-status
no snmp trap link-status
isdn switch-type primary-net5
isdn overlap-receiving
isdn protocol-emulate network
isdn incoming-voice voice
no isdn outgoing display-ie
no cdp enable

voice-port 1/0/0:15
timeouts interdigit 5
timeouts wait-release 5

dial-peer voice 700 pots
tone ringback alert-no-PI
destination-pattern 7....
port 1/0/0:15
forward-digits all
dial-peer voice 110 voip
preference 1
destination-pattern 2....
session target ipv4:
dtmf-relay rtp-nte
ip qos dscp cs5 media
ip qos dscp cs5 signaling
dial-peer voice 70 pots
tone ringback alert-no-PI
preference 2
destination-pattern .....
port 1/0/0:15
forward-digits 4

Please suggest the configuration on router or CUCM that need to be done so that DTMF works between CUCM & Siemens.


Abhas Jain

change 110 voip to dtmf-relay h245-alpha and see if it works

Hi Auppal,

Thanks a lot. Below command resolved the issue:-

dtmf-relay h245-alpha


Abhas Jain

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