DAHDI Outdial To Cell Phone Playing Music

We’re placing outbound calls over an analog line. Some of these calls are going to cell phones that play music rather than providing a standard ring. As a result, the Dial command sometimes returns a DIALSTATUS of CHANUNAVAIL and sometimes it returns BUSY. The problem is that this is happening on calls that are being answered.

Has anyone else run into this problem and if so, is there a solution?


How the cell phone alerts the user is irrelevant in terms of what goes over the air or over the wire.

The problem is that the cell phone is providing music rather than the normal ringback (I’ve also seen this referred to as a “coloured ring”. If you call the phone manually, instead of the caller hearing it ringing, the caller hears music. The Dial command doesn’t recognize the music as being a valid ringback tone and so provides an inaccurate Dial Status.

In the UK, and even in the US for toll calls, that would be anti-social, as the caller will be paying for hearing the music.

At the very least, you need answer supervision enabling, although I don’t know if Asterisk turns off tone detection after getting it. I wasn’t previously aware that it did tone detection before signalling ANSWER downstream, when there was no supervision.

They should, at least, allow some real ringback, then give a burst of silence, before sending anything that could spoof a call progress tone. Are these people who want to be called by you?

The call isnt answered, I only know of a few people using it, and I dont think Asterisk supports it too well , Turn off call progress tones and see how it goes.

blog.tekelec.com/blog/bid/12292/ … arly-Media

mobiletechnews.com/info/2004 … 20451.html

nma.co.uk/news/orange-opens- … 82.article


Actually, Ian’s URLs indicate it is the network, not the phone, which is what confused me about the answer status.

This looks like another triumph of marketing over technical common sense! I believe analogue systems always use early media for everything except answer. Spoofing call progress tones seems an inevitable result.