grn@stl.stc.co.uk (Gary Nebbett) (05/16/89)
Should a modem that originates a call send any tones? We have a number of modems at STL, some of which do not seem to interwork. When I use a modem to call a number which does not have an attached modem and listen to the line I find that some modems send an intermittent tone whilst others are silent. Looking at the V25 spec. I would expect the calling modem to generate "calling tone" which should be a 1300Hz tone lasting 0.5-0.7s at 1.5-2.0s intervals.