Comments
Asterisk use it for storing its dial plan & for more info see link below
http://codepoets.co.uk/linux_asterisk_setup_with_pstn_iax_and_sip
Posted by Hash007
The extensions.conf is the most important Asterisk file and it has the main objective of defining the PBX dialplan for each context and therefore for each user
The "extensions.conf" file is made up of sections or contexts between brackets [ ]
There are always two special contexts; [ general ] and [ globals]
Posted by sagitraz
The configuration file "extensions.conf" contains the "dial plan" of Asterisk, the master
Plan of control or execution flow for all of its operations. It controls how incoming and
Outgoing calls are handled and routed. This is where you configure the behavior of all
Connections through your PBX.
Posted by carlos33