iPhone DTMF digits duplicating when calling into IVR on multi-tenant Asterisk system

Posted on 2011-09-30
Last Modified: 2012-05-12
We are noticing intermittent issues where users are calling from iPhones on ATT network. They get to the IVR then the digits are not read properly. The user will type 4321 and 432211 or 44332211 is what Asterisk sees. The pattern hasn't been consistent, and it doesn't always happen. Anyone else experience this issue or have a solution?
Question by:lanlinehelp
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LVL 20

Expert Comment

by:José Méndez
ID: 36897039
Not a solution mate, but have you contacted AT&T? What can you possibly do if their network for some reason duplicates or receives duplicate tones from iPhones? If you could at least decipher the pattern, you may think of some crazy way to treat those and strip extra digits.... but we dont know it yet.  Sounds right?

Author Comment

ID: 36899533
We called AT&T, they of course say if the call connects. It's not them. Sigh
LVL 20

Expert Comment

by:José Méndez
ID: 36901427
My humble opinion is , that the person who told you that, doesn't really know what he is talking about. I am assuming your connection is either  a SIP trunk or an ISDN circuit. Neither technology will fail calls due to a DTMF issue. Can you tell us which one we are dealing with?

Accepted Solution

lanlinehelp earned 0 total points
ID: 37115335
The problem ended up being an issue on the AT&T network that they don't admit too.

DTMF from certain towers seems to be read by Asterisk incorrectly.

Ended up routing calls around the issues.

Author Closing Comment

ID: 37136703
It was an odd solution but it worked. We routed calls from one PRI to a SIP provider that seemed to get around the DTMF issue.

VOIP is always interesting.

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