jackson@decwrl.dec.com (Dick Jackson) (06/18/91)
We are running compressed video at 128 kbps over ISDN. Currently we are using Gandalf TA-1 TAs which support two V.35 ports and two RS-366 control ports. This TA has obviously been designed to be compatible with compression codecs such CLI's Rembrandt. We have the Gandalfs to be good performers, the problem is that lacking direct RS-366 control, we use the codec to do call setup and the bloody thing does the two calls in series, taking over 20 seconds (presumably it thinks it is working into the switched 56 kbps service, although I don't know why it would need to take so long). We would like to find a TA with two V.35 ports which is capable of being controlled via an RS-232 interface for call setup, etc. Fujitsu have been promising such a thing for a while but have not come through. Hayes and Northern Telecom have TAs with the Hayes command set, but only one V.35 port and I don't know how you could do Hayes commands through a synchronous interface anyway. We know of an inverse mux from Ascend Corp. which would do this job, but it is kind of pricy at over $4K. Maybe the answer is to somehow install RS-366 ports into our PC, but we don't know how to do this (i.e. don't know if there any products which support it). I would appreciate hearing from anyone who knows of any suitable products for our application. Thanks in advance. Dick Jackson