I believe we should be able to get down to about 50 or so ms. It would be interesting to see if this is a zaptel issue, or if it's an issue of DTMF frames getting called between AGI calls.
Mark On 26 Feb 2003, Steven Critchfield wrote: > On Wed, 2003-02-26 at 11:44, Alan Murphy wrote: > > Hi everyone, > > > > We are using an AGI script (Java) to read a code and other details sent > > by a user using DTMF tones. The version of Asterisk we are using is one > > from CVS - approximately 2 weeks old. We have two X100Ps as interfaces > > to the POTS lines. We are based in Ireland, using KewlStart signalling. > > > > The problem is that, when a user enters the 6 digit code too quickly, > > Asterisk does not seem to be able to keep up. Firstly, we used the "GET > > DATA" method to retrieve all the digits. What usually happens is that > > only the first 3 digits are returned, although sometimes it simply > > returns a null string if the digits are pressed very quickly. When the > > script identifies that this code is invalid, it loops to ask the user to > > re-enter. However, when we attempt to read the input again from > > Asterisk, through the standard input as before, it returns a null > > string. In fact, any attempts after this to read from the input stream > > fail (of course I issue a command to Asterisk before each attempted > > read). > > > > We tried increasing the number of digits for Asterisk to read, but it > > had no affect. We also tried the "WAIT FOR DIGIT" method and looped for > > each digit. It was a little better, but failed when the digits were > > pressed very quickly. > > > > To me, it looks like Asterisk is receiving the tones, but is overflowing > > some buffer somewhere. Can anyone shed some light on where the problem > > lies? > > What do you consider too quickly? I think the standard is for the tone > to be atleast 80 ms, but most hardware will tolerate as low as 45 ms. If > you drop below this amount you are not going to get decoded period. Also > on a phone that lets you send such short DTMF codes, you may run into a > problem of them not generating a true DTMF code. I have noticed > screechings out of cheap phones before it settles on a proper tone, and > sometimes wiggling the key made the tone variable. > > On a slightly nicer phone like the one I have on my desk, it seems to > send a constant length tone no matter how short or long the keypress was > for. I even can type ahead of it and it will eventually catch up to me. > In this arrangement and with a perl based AGI script, I have never > received a bad DTMF decode. I also use 'wait for digit' as I have need > to build my own buffer that is clearable. > > Also do you feel that java will be able to scale on your current > hardware to a point that you are comfortable. I know that I start having > trouble on my current hardware at around 18-20 concurrent perl apps > running, but only when they are moving lots of data, or during initial > startup. > -- > Steven Critchfield <[EMAIL PROTECTED]> > > _______________________________________________ > Asterisk-Users mailing list > [EMAIL PROTECTED] > http://lists.digium.com/mailman/listinfo/asterisk-users > _______________________________________________ Asterisk-Users mailing list [EMAIL PROTECTED] http://lists.digium.com/mailman/listinfo/asterisk-users
