|Summary:||ASTERISK-00530: [request] AGI TDD support needs delay between receive and send|
|Date Opened:||2003-11-15 21:53:21.000-0600||Date Closed:||2011-06-07 14:05:28|
|Description:||When communicating with a TDD, it is important to delay slightly between receipt of a character and sending of one. This is especially critical when the received character is a shifted character (punctuation, numbers), as if Asterisk immediately sends something, it will be in the wrong shift mode and appear garbled. Even without the shift mode problem, however, it would be a problem as the first few characters won't appear on a TDD.|
I've worked around this by including a "sleep 1" in my Perl AGI scripts right before any SEND TEXT command that follows a RECEIVE CHAR command. Obviously you only want the sleep when there is a switch between receive mode going to send mode and then it is only needed when a character was actually received. You don't want to delay for every character that you send, as some scripts may send one character at a time (for example, a TDD simulator).
****** ADDITIONAL INFORMATION ******
The following AGI will produce ugly output:
This script produced garbage on my Ameriphone Q90 TDD.
TDD MODE "on"
SEND TEXT "TYPE SOMETHING SHIFTED GA"
RECEIVE CHAR 60000
SEND TEXT "SEE THIS DOESNT SHOW UP RIGHT"
|Comments:||By: James Golovich (jamesgolovich) 2004-03-26 01:39:56.000-0600|
Does anyone have an idea how much of a delay we really need here? I suspect a whole second is too long, maybe 50-250ms?
Is there some spec on this? or if I came up with a way to adjust some timing could you try out some different values?
By: twisted (twisted) 2004-04-29 09:14:42
HouseKeeping - request for more information made on 3-26-04 (over a month ago) and no response recived from submitter. If this requires continuation, please re-open. Thanks!