Subject: JPEG in INVITE

From: "Alvir Alisic (ECS)" <[email-masked]>
Date: Thu, 23 Dec 1999 10:12:47 +0100

Hey!!!

I want to send JPEG pictures in my INVITE messages, but I don't know how I can do that. Is there anyone who can help me???

Marry Christmas and Happy New Year

Kind Regards
Alvir

Alvir Alisic
M. Sc Candidate - Datacom Software
Ericsson Mobile Communications AB
Lund, Sweden
mailto:[email-masked]  
phone:+46 (0)46 19 38 39

---

From: Scott Petrack <[email-masked]>
Date: Thu, 23 Dec 1999 03:55:55 -0500 (EST)

If your intent is to put it in the INVITE itself as a kind of "caller id
gif", then I say just put it in a separate MIME part as image/jpeg. 
The INVITE itself uses multipart mime. The first part should be
application/sdp and then the subsequent parts could be image/jpeg,
audio/wav, text/plain,whatever. The receiver(s) of the INVITE would show
the image, play the wav, display the text, whatever.

I have had discussions in the past where people have hosed me for this,
saying that more explicit signalling is needed, but I claim it's pretty
clear that if I get some attached media in the payload of an INVITE, the
intent is that this media should be played-out/displayed at the receiver
of the INVITE. Of course, this is not standard SIP, but that shouldn't
upset older implementations -- they will just throw the extra payloads on
the floor. If the older implementations are too stupid to deal with any
MIME type other than application/sdp, all they have to do is return an
error with 415 Unsupported Media Type (the reason phrase here really
should be changed to "Unsupported Content-Type" or "Unsupported message
body format"), along with Accept: application/sdp, and then the sender can
try again. If you think that this adds extra round trips into the
signaling, I would say that an implementation can have a pretty good a
priori guess as to the chances of success in sending such a multipart MIME
INVITE.

I have always thought that the ability to send a thumbnail sketch as
caller ID is a very cool feature that SIP can do very naturally.

Scott