Section 3 : Running a Server

Q318: What is the purpose of putting '@' at the end of the dial string?

Q.

What is the purpose of putting '@' at the end of the dial string?

Could someone explain the purpose or advantage of putting '@' at the end of the dial string when dialling out in FAX mode?

The modem manual (Worldblazer) says it puts in 5 seconds of silence, but it is not clear from the FlexFAX docs or the modem manual why or when this is a Good Thing (unless I have missed it).

Currently I don't have the '@', and it seems to work OK.

A.

The @ is used to get result codes that disambiguate "NO ANSWER" from "NO CARRIER". That is, whether the phone was not answered, or whether it was answered, but no carrier was recognized. By doing this one should be able to recognize when a person answers the phone (and thereby not redial). Unfortunately some modems do not properly implement @ and/or do not return useful results that permit one to recognize when a non-modem answers the phone. The ZyXEL is a prime example of a modem that does not implement the @ dial modifier correctly. I personally would never setup a high-volume fax service with a modem that did not properly implement the @ dial modifier because of the potential for harassing folks as a result of dialing wrong numbers.

BTW, the "@-trick" is due to Stuart Lynne.

FAQ Index

Q319: How do I automatically add a 9 to the fax number?