[asterisk-users] Outbound call: caller gets no ringback on session progress

[Joshua C. Colp]

On Sun, Dec 16, 2018, at 4:43 AM, Michael Maier wrote:

<snip>

> 
> Another question: is there any use case for 183 Session Progress w/o 
> SDP? IOW: Is a 183 Session
> Progress just a bug of the ISP? If so, problem could be solved by 
> dropping each 183 package w/o SDP.

Nothing really comes to mind that would be accomplished by sending a 183 without SDP but there may be cases on the internet.

-- 
Joshua C. Colp
Digium - A Sangoma Company | Senior Software Developer
445 Jan Davis Drive NW - Huntsville, AL 35806 - US
Check us out at: www.digium.com & www.asterisk.org