On Mon, Apr 20, 2009 at 3:29 PM, Kevin Spencer <spenk.l...@googlemail.com> wrote: > Dave, > Thanks, thats clear from the point of view of the arbitrary binary body. > Vikram, > But in the case where no offer is made in the initial INVITE surely there is > no need to indicate a content-type at that stage (it may not be known at > that point?), for example the "Session via Redirect and Proxy Servers with > SDP in ACK" scenario in 3665 shows the initial INVITE with a content-length > 0 but no content-type header. As such, there is no defined behavior in case Content-Length 0 is defined and Content-Type is missing. I have seen few UA which rejects initial INVITE without SDP if it has missing type. On the safe side, you might want to include the type even though length is 0. > > In this context would it be correct to say that while the type isn't > necessary you should still be prepared to receive it while not necessarily > acting upon it? For the above context, yes, we should be lenient enough to recieve or not receive the type if length is 0. But we can not generalize as it very much depends on the type and context. >Or, in the case of an SDP body does 0 length have no > significance and the content-type shouldn't be used, and rejected if > received - I don't see that in 4566 or 3264 though. I do not think RFCs should be that harsh and define the behavior for unexpected scenarios where presence or absence of something does not violate anything. > > Thanks for the responses, > /K > > On Mon, Apr 20, 2009 at 10:15 PM, Dale Worley <dwor...@nortel.com> wrote: > >> On Mon, 2009-04-20 at 16:21 +0100, Kevin Spencer wrote: >> > Does anyone have any suggestions as to under what circumstances you would >> > consider including a Content-Type: header when your Content-Length: is >> zero? >> > 3261 gives the following example in section 20.15: >> >> I don't know of any current application, but SIP is careful to allow the >> body to be an arbitrary (binary) object of any type. As such, we must >> provide for the possibility that for a particular media type, a content >> of zero bytes has a useful meaning. >> >> Dale >> > > On Mon, Apr 20, 2009 at 6:4 PM, Vikram Chhibber <vikram.chhib...@gmail.com> > wrote: > >> You will carry Conent-Type with 0 Content-Length when you say "I am >> carrying 0 length XYZ Content-Type", which is different then saying "I >> am carrying no body with an type". Typical scenario would be INVITE >> without offer sdp. You still need to have Conent-Type as >> "application/sdp". If you remove Content-Type itself, you can receive >> 488 response. >> Example of 0 Content-Length and no type would be BYE message where you >> typically do not send any body. > _______________________________________________ > Sip-implementors mailing list > Sip-implementors@lists.cs.columbia.edu > https://lists.cs.columbia.edu/cucslists/listinfo/sip-implementors >
_______________________________________________ Sip-implementors mailing list Sip-implementors@lists.cs.columbia.edu https://lists.cs.columbia.edu/cucslists/listinfo/sip-implementors
