Channel is not created

Asterisk Asterisk Support
1

Hi friends,
while i am trying to communicate with two SJphones(Clients), the server (Asterisk) is not able to create the channel, in the log file it showing the following error messages.

391 [Oct  6 17:31:04] WARNING[6074] app_dial.c: Unable to create channel of         type 'SIP' (cause 20 - Unknown)
392 [Oct  6 17:32:37] WARNING[6079] app_dial.c: Unable to create channel of         type 'SIP' (cause 20 - Unknown)

Why the channel is not creating.

2

This is a very non-specific message. Typical reasons may be referencing a non-existent section in sip.conf.