I've a problem with DTMF relay only on outbound direction in this topology scenario:
SIP ISP <---SIP--->Cisco UBE ISR 2811 <--SIP---> Cisco UCM 8.6.X <---SCCP---> IP Phone
I'm using codec g711 with the provider that tell me to use in-band DTMF.
SIP trunk in CUCM 8.6 configured as standard without MTP flag, outbound and inbound calls works fine, but DTMF relay works only from SIP provider to Cisco IP Phone.
From inside, any DTMF tone are not relayed to the SIP provider.
For example, call from SCCP Phone to my mobile phone, from mobile phone I can't hear any DTMF composed to the SCCP phone, but DTMF composed from the mobil ephone are recived to the internal SCCP phone.
This happen always the same in that two scenario:
Mobile phone ------> SIP ISP ---SIP--->Cisco UBE ISR 2811 --SIP---> Cisco UCM 8.6.X ---SCCP---> IP Phone
IP Phone ---SCCP---> Cisco UCM 8.6.X ---SIP---Cisco UBE ISR 2811 ---SIP--> SIP ISP ----> Mobile Phone
Can anyone help me?
Thank you very much