[Asterisk-Users] T1 Hardware Echo Can

[Rich Adamson]

Brent,

Best think through what you're trying to do here. You have multiple
choices on how to interface * to the traditional pstn world, including
the x100p, tdm cards, multiple T1 interface types, external gateways,
etc.

The x100p and tdm cards have an internal 2-wire to 4-wire hybrid that
is built into the chipsets on those cards. In order to use an external
echo can with them, you'd have to change that to a 4-wire to 4-wire
arrangement, which cannot be done. The chipsets weren't engineered for that.
Since the majority of echo issues with these two cards are the result
of the card's hybrid (and internal * echo can functions), simply disabling
the echo can function and attempting to replace that with an external
echo can box won't accomplish anything. (The problem is already
existing in front of that external box.)

If you install a T1 card and an external T1 mux (with fxo cards), the
echo can function already exists within the mux and/or cards. Don't
really need 'another' external echo can box unless you actually 
purchased a T1 mux that didn't have echo can in the first place (and
they do exist). 

If you install a PRI (or related types of channelized T1 arrangements),
you don't need an external echo can function as those interfaces are
generally 4-wire to 4-wire interfaces already. If echo exists, its 
generally the result of other interfaces (located somewhere else) and
those locations should be addressing the corrective actions needed to
resolve the issue.

If you only need a small number of fxo ports, pstn gateways in the form
of Cisco boxes, Mediatrix 1204, as well as many other products can do
that at a relatively inexpensive cost. The echo can function is built
into those boxes, which do work. Each comes with additional 
considerations or issues however.

Lots of choices....

> > ----- Original Message ----- 
> > > After reading the lists and taking reccomendations from TC, I have
> finally
> > > given up on the echo can built into asterisk.  I am sick of hearing
> > > complaints from users, so the money spent on a hardware echo can will be
> > > worth its weight in gold.
> > >
> > > I am curious however, about some setup and component requirements.  It
> > > seems as if every telecom place I call, either never calls back or
> doesn't
> > > have a clue what I am talking about.  Does anyone have any good
> companies
> > > with competent sales/engineer people who would help put together a
> > > solution.
> > >
> > > Also, for anyone that has hooked up a echo can before.  Do you have to
> buy
> > > such a large shelf?  Obviously things things are intended for ILEC
> > > installs, however, I can't find anything geared towards the PBX realm.
> It
> > > seems everything on Ebay is a 32 module shelf rack.  Thats a bit over
> kill
> > > for us.
> > >
> > > Further, I would imagine this setup.  Please correct me if I am off
> base.
> > > I would have a straight T1 cable from the Channel Bank to the Echo Can,
> > > and then a X-over from * to the Echo Can.  How are these solutions (e.g.
> > > Tellabs) wired up?   Are there RJ45 connectors on the back of the shelf,
> > > or is it a strip the wire and twist method?
> > >
> > > Any assistance that anyone can provide to myself (and the list) would be
> > > greatly appreciated, as there are many people who would benefit from
> > > this...
> > >
> > > Thanks!
> > >
> > > - Brent