Grandstream GXP2100

Hello everyone,

I have strange problem with this telephone. When I’m calling some call center with IVR options, and when I dial some optines, the phone is not recgonize it. When I put yealink phone , everything is alright. So , the sip.conf is ok, is there any option on phone for this?


Did you contact the phone vendor? Its is probably best to contact them.

I didn’t. I hoped that is something simple and that somone has idea about it…:S

I had almost the same proplem with Grandstream GXP2000 phone, my suggestion is that on the phone you set up the dtmf to rfc2833, you can check this post

As ambiorixg12 mentioned, the issue that you are experiencing is related to your DTMF method. The GXP21xx series provides three choices for DTMF; In-Audio, RFC2833, or SIP-Info.

To verify you can select In-Audio first to see if it works. If not, you then then select RFC2833 or SIP-Info. You can also select all three at the same time.

You can find your “DTMF Method” settings by logging into the web UI and going to “Account” settings.

I will try to change this setting, and I will post feed back , I hope it will help, thank you all very much!


I have changed Send DTMF to : from RFC2833 to via SIP Info, and it is working now !
Thank you very much !

Best regards,