asterisk users - Jan 2007 - Absolute Timeout or Dial Limit option???

I need a method of limiting the duration of calls when RTP media does
NOT travel through Asterisk.
I know that the Dial() command limit option "L" requires Asterisk to
carry the media, but what about Set(TIMEOUT(absolute)=XX)?

Are there any other apps/options that might work for this?

Thanks!
David