[asterisk-users] placing calls with linphone.org SIP account

[Frank]

On Wed, 2016-01-06 at 11:27 +0100, Yves wrote:

>  how can I call other users 
> registered at other SIP-Providers?
> I tried all well-known SIP URI Syntaxes but none worked... does anyone 
> reliably know, if it is possible at all and if so, what is the
> dialstring looking like? 

It depends if the "other SIP-Provider" accepts calls from other
networks. 
Some providers accept calls from other networks. Unfortunately, most
providers do not.