Sending / Reciving SIP text (SMS) - between SIP clients


i have a number of sip clients that currently make and receive calls, however when trying to sent a text massage (using sip protocol) between each other i have to establish a voice call first to create a channel that i could use to send a text massage.

The problem with SendText() application is that
"SIP Supports text messaging during a call, but not outside of a call".

my sip client is Bria

This is AMI action

Action: SendText
Channel: SIP/1004-00000011 //as you can see i need to have an existing channel
Message: “Hi i am testing sending text using sip protocol”

From dial-plan

exten => 1004, 1, Answer()
exten => 1004, n, SendText(hello world)
exten => 1004, n, HangUp()

I really need your help
Thank you

Current versions do not have that restriction, although you must add special, message routing, entries to extensions.conf. I haven’t actually used the new feature, so there may be some remaining restrictions.

You didn’t say the version.

I am using Asterisk 11.2.0

Can you please give a hand on how it is done because i am new in this area.

Thank you