Which GUI is this with or did you write your own script ?
What is your primary language ?
It would have avoided confusion if you had used the standard AMI interface, rather than the AJAM one.
“=” is a reserved character in URLs, although it wouldn’t suprise me if AJAM tolerates the failure to URL encode the “=” after var1.
What I suspect is more likely is that the outgoing channel is considered to be a derived channel, and that you therefore need an “_” in front of the variable name, so that it propagates from SIP/1048-??? to SIP/101-???.
David, your language question was somewhat ambiguous. I think you meant what programming language, but as the questioner obviously isn’t a native Engilsh speaker, it could be interpreted as what natural language.