# DTMF being passed both ways

**URL:** <https://community.asterisk.org/t/dtmf-being-passed-both-ways/10994>\
**Category:** Asterisk Support\
**Created:** [December 12, 2006, 9:32am UTC](https://community.asterisk.org/t/dtmf-being-passed-both-ways/10994 "2006-12-12T09:32:03Z")\
**Posts on this page:** 2\
**Page:** 1

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**Author:** ![Kostya](https://avatars.discourse-cdn.com/v4/letter/k/d2c977/32.png) [@Kostya](https://community.asterisk.org/u/Kostya)\
**Post date:** [December 12, 2006, 9:32am UTC](https://community.asterisk.org/t/dtmf-being-passed-both-ways/10994/1 "2006-12-12T09:32:03Z")

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When using Asterisk to dial into a SIP provider, leaving dtmfmode as rfc2833 for that SIP ‘friend’ enables DTMF to be recognized by the SIP provider. Using a Dial(SIP/XX|10|t) should enable transfers on the SIP provider’s side, but Asterisk does not recognize the DTMF thats required to initiate transfers when using dtmfmode=rfc2833.

When I switch to inband in sip.conf, Asterisk now recognizes the DTMF and initiates the transfer but the DTMF no longer get passed to the SIP provider.

I have tried INFo and AUTO dtmfmode, and have not had luck getting DTMFs to be recognized both ways.

Is there a way to pass DTMFs through Asterisk from the callee and called side?

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**Author:** ![IronHelix](https://avatars.discourse-cdn.com/v4/letter/i/da6949/32.png) [@IronHelix](https://community.asterisk.org/u/IronHelix)\
**Post date:** [December 12, 2006, 3:20pm UTC](https://community.asterisk.org/t/dtmf-being-passed-both-ways/10994/2 "2006-12-12T15:20:33Z")

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this is an issue with your SIP provider. They are not encoding the DTMF being passed inward, so neither setting gets both sides of it.

I think your best bet might be to separate the sip.conf entry into an incoming and outgoing section.

IE

register =\> user:pass@provider\_in

[provider]  
blah blah blah same stuff you had before  
dtmfmode=rfc2833

[provider\_in]  
copy of above  
dtmfmode=inband