[Asterisk-Users] E1's and span - what questions to ask my service provider

[Peter Svensson]

On Fri, 4 Feb 2005, Michael Bielicki wrote:

> It's even easier. If you are taking an E1 with euroisdn, the D-channel
> will allways be nr. 16. In neary all cases the rest of the settings
> will be: ccs,hdb3 and depending on the carrier crc4.

Other things you will need to agree on / know:

 * Number of DID digits sent (usually the last 3-4 or all digits)
 * Number of digits and numbering plan for your outgoing callerid 
   (Calling Number on outgoing calls)
 * The numbering plans used for incoming caller id 
   on national/international calls.
 * The numbering plan expected for the called number on outgoing calls.
 * channel selection order. Normally a net end will hunt ascending 
   and a cpe interface will hunt descending. Make sure you are hunting
   in the opposite direction of the other end. This removes the risk of
   both ends trying to sieze the same B channel at the same time.
   Configured in Asterisk through the use of 'g' or 'G' on the channel 
   specification.

Peter