Digium, Inc.
Page 44
Chapter 3: Configuration
Framing:
T1 utilizes framing set for D4 (SF) or ESF. E1 utilizes CAS or CCS.
Coding:
T1 coding can be AMI or B8ZS. E1 coding can be AMI or HDB3. E1
can also have the extra flag CRC4 at the end for CRC4 checking.
Yellow:
The optional yellow flag can be added at the end for transmitting a
yellow alarm when no channels are open.
The following is a typical setup for a telco in the US:
span => 1,1,0,esf,b8zs
In Europe:
span => 1,1,0,ccs,hdb3
4.
Specify the channel definitions. The format is:
<device> = <channel list>
A list of valid devices are specified in the sample system.conf file.
The following is a typical setup for a T1 PRI in the US:
bchan = 1-23
dchan = 24
5.
DAHDI uses modular echo cancellers that are configured per channel.
The echo cancellers are compiled and installed as part of the dahdi-
