[Asterisk-Users] Qs about FXO/FXS cards

[Victor Rini]

Jim Van Meggelen wrote:
> 
> If I may, I'd like to ask you some general questions about the
> environment these systems are running in.
> 
> - How are these systems powered and grounded?

Not optimally by a longshot. On the Athlon machine, my main machine, all 
the equipment is plugged into 2to3 prong adapters. A ground tester shows 
that there is ground but I don't think the outlet is wired for ground - 
it's probably "grounded by accident".

The situation on the Via C3 machine is even worse. I have no ground on 
that outlet and no way of wiring it for ground short (no pun) of 
improvising some sort of ground by drilling into concrete or some such 
thing. I've never looked into it - just crossed my fingers and wished 
for the best. This system is my lower use system. I don't get many calls 
on it but I've never had to reboot it because of problems with the 
TDM400 or Asterisk. I dial out on the one phone connected to the system 
occassionally and I usually have availability and when I don't it's 
usually because the network has gone out on the Athlon box - the two 
boxes are iax/ethernet connected.

> - Are the lines feeding the FXO cards coming from the PSTN, or are they
> being fed by a PBX or similar? (basically, how long is the loop between
> the card and whatever is feeding it?)
> 
Yes, the lines come from the pstn. I pulled a run of Cat 5 along the 
outside of the house underneath the overhang of the cedar shingle siding 
for about 20-25 feet from the demarc through a drill hole to the Athlon box.

> You are successfully running systems that many would tell you to expect
> problems with. The TDM400 FXO modules are generally agreed to be an
> improvement over the X100P, so if you are having no troubles now, it is
> entirely plausible that migrating to TDM400-based FXOs will work for you
> as well. Unfortunately, there is no way of guaranteeing that, and it's
> your money, so I can't advise you much more than that.
> 
> Frankly, what is most interesting is the fact that your systems are
> trouble-free. Certainly if you were to ask if such systems could be put
> into production, you would probably be advised not to expect much.
>
You know what? To top it all off, I also use both systems as routers. On 
the Athlon box, I have three ethernet adapters one of which is a 
via-rhine embedded adapter. I run openvpn, folding at home and a netfilter 
firewall along with Asterisk on that Athlon box. One adapter is 
connected to the cable modem and another to a WAP. The Via C3 system has 
two ethernet cards as well and runs folding at home with Asterisk. Both 
systems are connected with a cheapie powerline/homeplug bridge. My only 
problem with all this is with the network on the Athlon box going down 
once in a great while. An ifdown/ifup is usually what it takes to fix it.

> There seem to be a lot of variables with these TDM400s.
> 
> Cheers,
> 
> Jim.
>