Re: [codec] #7: Providing DTMF Testing Tools and Samples

"codec issue tracker" <> Sat, 10 April 2010 05:40 UTC

Return-Path: <>
Received: from localhost (localhost []) by (Postfix) with ESMTP id 866EF3A6969 for <>; Fri, 9 Apr 2010 22:40:52 -0700 (PDT)
X-Virus-Scanned: amavisd-new at
X-Spam-Flag: NO
X-Spam-Score: -102.546
X-Spam-Status: No, score=-102.546 tagged_above=-999 required=5 tests=[AWL=0.054, BAYES_00=-2.599, NO_RELAYS=-0.001, USER_IN_WHITELIST=-100]
Received: from ([]) by localhost ( []) (amavisd-new, port 10024) with ESMTP id g9WrshBEpMdg for <>; Fri, 9 Apr 2010 22:40:51 -0700 (PDT)
Received: from (unknown [IPv6:2001:1890:1112:1::2a]) by (Postfix) with ESMTP id 3080A3A6892 for <>; Fri, 9 Apr 2010 22:40:51 -0700 (PDT)
Received: from localhost ([::1] by with esmtp (Exim 4.69) (envelope-from <>) id 1O0TR1-00021M-Km; Fri, 09 Apr 2010 22:40:47 -0700
MIME-Version: 1.0
Content-Type: text/plain; charset="utf-8"
Content-Transfer-Encoding: 8bit
From: "codec issue tracker" <>
X-Trac-Version: 0.11.6
Precedence: bulk
Auto-Submitted: auto-generated
X-Mailer: Trac 0.11.6, by Edgewall Software
X-Trac-Project: codec
Date: Sat, 10 Apr 2010 05:40:47 -0000
Message-ID: <>
References: <>
X-Trac-Ticket-ID: 7
In-Reply-To: <>
X-SA-Exim-Connect-IP: ::1
X-SA-Exim-Scanned: No (on; SAEximRunCond expanded to false
Subject: Re: [codec] #7: Providing DTMF Testing Tools and Samples
X-Mailman-Version: 2.1.9
List-Id: Codec WG <>
List-Unsubscribe: <>, <>
List-Archive: <>
List-Post: <>
List-Help: <>
List-Subscribe: <>, <>
X-List-Received-Date: Sat, 10 Apr 2010 05:40:52 -0000

#7: Providing DTMF Testing Tools and Samples
 Reporter:  hoene@…                 |       Owner:     
     Type:  task                    |      Status:  new
 Priority:  minor                   |   Milestone:     
Component:  requirements            |     Version:     
 Severity:  Active WG Document      |    Keywords:     

Comment(by hoene@…):

 [Raymond]: We can use real-world recorded DTMF signals if we want to, but
 we don’t have to. Yes, in our DTMF testing of BV16 we used a DTMF
 generator software to generate the waveform of 20,000 random DTMF symbols
 for each of 24 DTMF test conditions, for a total of nearly half a million
 DTMF symbols. After passing through the codec, the DTMF signals were
 passed through a PC executable program which simulated a DTMF decoder that
 was widely deployed in commercial VoIP applications. The decoded DTMF
 symbols were then compared with the original DTMF keys used to generate
 the symbols to calculate the error rates. As you can see, such a test
 method is purely based on software and can easily be duplicated by third
 parties.  If the codec WG decides not to do anything with DTMF, then
 obviously nothing further needs to be done, but if the WG decides that the
 codec candidate needs to be tested for DTMF pass-through, I will try to
 dig up our DTMF test software package and get internal approval to donate
 it to IETF for this purpose.

Ticket URL: <>
codec <>