[Asterisk-Users] Testing two E400P with E1 cross-cable

[Leo Ann Boon]

I'm using a self-made cable with just 4-wires to hook up 2 E100P. Has 
been working for few months without trouble. Just connect:
Pin 1 to Pin 4
Pin 2 to Pin 5
Pin 4 to Pin 1
Pin 5 to Pin 2

It's the same as a T1 crossover cable. IIRC, the E1/T1 sends signal out 
on pair 4/5 and receives on 1/2. So, crossing the pairs should be 
correct. Some Cisco docs also described the same thing (for connecting 
their voice routers to your PBX).

Regarding the grounding or so called shielding, I was told it has to be 
properly done according to telco specs. In fact, some E1 vendors will 
explicitly state that you should get someone qualified to make the cable 
if it involves the grounding.

So far, I've been running fine without the grounding. I think it's ok if 
the distance is short, but if the distance is far I think you're better 
off with proper grounding. It would be helpful if someone can help 
clarify this. My gut feel: it's probably very important if you've ever 
seen the thickness of ground cables used in the COs.

Cheers.

Carlos Carús wrote:

> Jared Smith escribió:
>
>> I have a funny feeling your crossover cable might be wrong... I'm not
>> sure about an E1 crossover, but I know that a T1 crossover is different
>> than a standard ethernet crossover.  (See
>> http://www.jaredsmith.net/misc/cables/)  If you do find the pinout for
>> an E1 crossover, let me know and I'll add it to my site.
>>
>> Jared Smith
>>
> Right now I'm testing this pinout:
> pin1 (Rx -)      <--> pin4
> pin2 (Rx +)      <--> pin5
> pin3 (Rx Shield) <--> pin3
> pin4 (Tx -)      <--> pin1
> pin5 (Tx +)      <--> pin2
> pin6 (Tx Shield) <--> pin6
> pin7 (not used)  <--> pin7
> pin8 (not used)  <--> pin8
>
> I don't know if this one is the good one, but zttool says it's ok. I'm 
> not sure, but E1 and T1 cables should be the same...
>
> Best Regards,