[Asterisk-Users] Hardware Compatibility and zaptel driver

[Steve Underwood]

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