[Asterisk-Users] Question :: groundstart and loopstart

[Jim Gottlieb]

On 2003-06-17 at 16:05, Surfer Dude (swell at labranch.com) wrote:

>    Can I assume that my lines are indeed groundstart?

If you pick up your line on a normal phone and hear dialtone, then you
have loop start.  If you had ground start, you would need to ground one
side of the line to get dialtone.

The nice thing about ground start is that it gives you guaranteed
disconnect supervision.  It seems your channel bank may think that loop
start lines do not give CPC (disconnect supervision) and so it isn't
looking for it.

Whenever possible, it is better to use ground start lines.  However,
most FXO cards will not support ground start origination.  Calls
terminating on ground start lines usually provide ring voltage as well
as the ground signal, though I have seen some braindead equipment that
does not send ring voltage for ground start lines.

As far as I have been told, ground start does not exist outside North
America.  I would love to be proven wrong on this because getting good
disconnect supervision in other countries has always been a problem for
us.  The wide availability of PRI somewhat obviates this need, but
sometimes we can not justify the cost when we only need a few lines.