[Freeswitch-users] How long did the phone ring?

Kristian Kielhofner kristian.kielhofner at gmail.com
Wed Mar 17 12:50:57 PDT 2010

They are referring to SIP 180 and SIP 183.

It's kind of a mess (it is SIP) but both are non-final response codes
to indicate call progress.  Typically speaking, 180 Ringing is
returned without media and tells the receiving device (FreeSWITCH or
your local SIP phone in this case) to activate a local ringback
generator to inform the caller the remote end is progressing.  180
without media is typically used when calling SIP phones.  They know
that they only actually "ring".

183 is typically used with media.  The media contains audio to tell
the caller what is happening.  Typically this audio sounds just like
ringback (depending on region) but it could just as easily be a
ringback tone (Britney Spears or anything else), audio from the remote
end, or just about anything else the caller might need to know (even
an error message).

Most carriers *should* consistently give you 183 with media while the
call progresses, whether the remote end is actually ringing or not
depends.  You have to listen to the audio :).

BTW, as are most things with SIP these are generalities and many not
happen in your environment, most stacks, for example, will handle
180/183 interchangeably - it's the presence of media (SDP) that

FreeSWITCH has a multitude of options to deal with these scenarios.
First things first - what does your carrier return?

On Wed, Mar 17, 2010 at 3:18 PM, Fraser Redmond <fraserredmond at gmail.com> wrote:
> Sorry - newbie question: what is the 180 or 183? Can I manipulate that any
> way?

Kristian Kielhofner

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