asterisk users - Mar 2008 - Hardware supporting groundstart signalling

Hello! Recently I posted a question about an installation I have that was
experiencing glare problems. The solutions presented were to use inverse inbound
and outbound line groups and to use groundstart signalling. As it turns out, the
Sangoma A400D card that is in use does NOT support groundstart. I've
confirmed this with a Sangoma engineer and their support staff. I've also
read that Digium products do not support groundstart signalling. Since glare is
a common problem with analog PBX systems, it would make sense that groundstart
is a common signalling type. Why do the major manufacturers not support this? If
you're using groundstart, what hardware are you using? Thank you!

Tim Nelson
Systems/Network Support
Rockbochs Inc.