[Asterisk-Users] Hardware Compatibility and zaptel driver

[Nir Simionovich]

Hi Steve,

  Hmmm.... lets see, NOT !

  In Israel the connection of the E1 at the wall socket is not an RJ45, but
a British Connector.

  I'm fully aware of the fact that the connection of E1 on the Router/Server
side are 1,2 and 4,5 as pair for TX and RX. Steve, my question may sound a
little stupid, but
here is my current setup.

1. The cable connecting from the wall to the server is a flat 4 wire cable,
used by our Telco.
2. The cable also has a noise filter on it, the same one used for Data
Connection by our Telco.
3. The cable is around 60cm long, which means that it's just the right
length.
4. The length of connections from my wall socket to the E1 Grouping device
is around 30 meters,
    well within the specs.

  However, what you said poses a really interesting question. Although I'm a
CCNA, I couldn't find an answer to it. As far as I know, E1 is supposed to
be an un-balanced
medium, which suggests that there is no significance to the order of wires
within the pair. Question is, is this true? If not, this might be the cause
of problems. However, the line works fine
from my side, and I due to the fact that I can't see any errors on my side
(actually, I don't have an
ability to see errors), I'm a bit at a loss.

  Now, here are the symptoms according to our testing (The Telco and
Myself):

1. We've managed to bring down the number of errors to around 60 per hour.
    This was achieved by changing the default ToneZone in zaptel.conf to FR,
while before it
    was set to UK. That's why I believe that the problem resides zomewhere
in the zonedata.c file.
2. When errors go up, I can create outgoing calls, but incoming calls
receive busy signals on all         PRI channels.
3. The errors seem to go away without any specific reason. The only common
denominator
    for reseting the errors is, performing several resets to the zaptel
driver and performing a
    reset to the Telco System 12 connection card. And only after a variable
number of resets,
    everything works fine again.
4. It can work fine for a couple of days, and then start making hell.

  Well, that's basically it, if anyone has an idea, I'm open.

Regards,
  Nir S

> ----- Original Message -----
> From: "Steve Underwood" <steveu at coppice.org>
> To: <asterisk-users at lists.digium.com>
> Sent: Monday, March 10, 2003 5:15 PM
> Subject: Re: [Asterisk-Users] Hardware Compatibility and zaptel driver
>
>
> > Hi Nir,
> >
> > Let me guess - you used an EtherNet cable to connect the E1 port to the
> > Telco's box on the wall, and it is several metres long?
> >
> > Although the plugs look like EtherNet plugs the cable actually has the
> > wires paired differently. The crosstalk of just a few metres of cables
> > incorrectly paired like this is often enough to give a gentle stream of
> > bit errors. Cat 5 cable is OK. The EtherNet plugs are OK. They just need
> > to be wired differently.
> >
> > Regards,
> > Steve
> >
> >
> > Nir Simionovich wrote:
> >
> > > Hi All,
> > >
> > >   Well, as some of you alrady saw myself and Optimus on the IRC
> > > channel, I guess you already
> > > know us. In any case, I've been battling the following issues during
> > > the past few days:
> > >
> > > 1. My Telco claims that he can see many CRC4 errors originating from
> > > my side of the PRI line.
> >
> > If your line dies and you can see smoke pouring from the local exchange
> > building, the Telco will still say the problem is your fault. It seems
> > to be a basic quality of Telcos in every country :-)
> >
> > >     Although I see that everything looks fine, I can't really see if
> > > there is a CRC4 problem. I've
> > >     managed to play around with zaptel.conf, and when I set the
> > > tonezone to FR, the number
> > >     of errors decreases. I think that the problem resides withing the
> > > definition in the zonedata.c
> > >     file, however, I didn't find any explenation of the files syntax.
> > >     I may be barking up the wrong tree here, but if anybody has a
> > > better idea, I'd love to hear it.
> > >
> > > 2. I've been asked to find some additional hardware to work with, and
> > > the only thing listed as a
> > >     PRI line card on the Digium site is Dialogic. Dialogic E1 cards
> > > cost around 6000$ !!! Which
> > >     about 10 times more than Digium. Has anyone got any experience
> > > with another PRI card that
> > >     works with Asterisk?
> > >
> > >   Apart from these 2 issues all is working fine, and we are very happy
> > > with the Asterisk. I will be
> > > sending everybody some nice figures soon, so hold on tight. Oh, just
> > > to do something funny, try
> > > performing the next trick:
> > >
> > >   Configure a single PRI line with 30 channels, call the first channel
> > > which calls the second channel,
> > > which calls the third channel and so on, till you get to 30. Now, take
> > > the target phone ear piece, and
> > > bring it up to the microphone of the source number. Say something next
> > > to it, and you will hear the
> > > delay of voice on your machine :-) Results tend to be very amuzing :-)
> > >
> > > Nir S
> >
> >
> >
> > _______________________________________________
> > Asterisk-Users mailing list
> > Asterisk-Users at lists.digium.com
> > http://lists.digium.com/mailman/listinfo/asterisk-users
> >
>