[Asterisk-Users] Digium E100P or TE410P card

[Peter Svensson]

On Fri, 19 Nov 2004, Michael Devenijn wrote:

> We are located in Belgium and just ordered a PRA line, the telco asked
> the following questions : 
> 
> -          120 or 75 ohm ?

120 ohm is delivered over two balanced twisted pairs and normally 
terminated in an rj45. This is what you need for the Digium cards.

75 ohms are delvered as unbalanced koaxial cables, normally terminated in 
a BNC connector.

> -          Support for CRC4  yes/no ?

CRC4 is normally used. I assume it has some benefit (signal integrety?)

> -          B channels in 2 way ?

This one I am not familiar with. 

> We will buy a digium card but which one should we buy ?

The TE410P (and the TE405P) are four-port cards. They are handy if you 
have or plan on having more than one E1 connected to the system. 

Peter