Are you sure the in the failed call leg the terminating Sipp is indicating support for telephony event in the 200 OK SDP ? SIP logs for both the calls would be useful. From: freeswitch-users-bounces@lists.freeswitch.org [mailto:freeswitch-users-bounces@lists.freeswitch.org] On Behalf Of Pete Kelly Sent: Friday, June 05, 2015 8:06 AM To: FreeSWITCH Users Help Subject: Re: [Freeswitch-users] rfc2833 DTMF behaviour Is there anything obvious I can check in the rtpevent packets to suggest why FreeSWITCH would: - For UAC A - report receiving DTMF and successfully forward it to the bridged UAC - For UAC B - report receiving DTMF and *not* forward it. Both UAC's A and B show freeswitch reporting it has received the DTMF but only DTMF from UAC A gets forwarded to the bridge. Same dialplan/sip_profile/dialled extension. I feel sure it must be something within the DTMF packet itself that FreeSWITCH is not liking and therefore not forwarding On 4 June 2015 at 17:12, Pete Kelly <pkelly@gmail.com<mailto:pkelly@gmail.com>> wrote: Hi I am trying to send rfc2833 DTMF with SIPP into FreeSWITCH and have the DTMF be passed along to the bridged leg. If I set up the following scenario: Bria > FreeSWITCH > SIPP and press a DTMF tone on Bria, I see the DTMF received in FS and then it being sent out to the bridged leg. However if I replace Bria with SIPP and play one of the SIPP supplied rfc_2833 pcaps, I only see the DTMF being received by FreeSWITCH but it is not sent to the bridged leg. Does anyone have any suggestions? This is the log indicating FS is receiving the DTMF from SIPP 2015-06-04 15:41:57.343854 [DEBUG] switch_rtp.c:6092 RTP RECV DTMF 2:2240 2015-06-04 15:41:57.343854 [DEBUG] switch_channel.c:488 RECV DTMF 2:2240