On 07/24/2012 07:14 AM, Aleksey Entsov wrote: > Hi Everyone! > > In some call scenario I have incoming 180/SDP. > And SDP contains this line: > ..... > a=rtpmap:101 TELEPHONE-EVENT/8000 > ..... > > My gateway cannot parse this string "TELEPHONE-EVENT/8000" because upper-case > letters are used. If "telephone-event/8000" string comes in lower-case > letters only, > then it's fine. Value of "a=" field can be parsed. > > So the question is: > Is it allowed to use upper-case letters for "TELEPHONE-EVENT"? > I was searching through RFC, but could not find the explicit approval. > > > RFC4566 says "An SDP session description consists of a number of lines of > text of > the form: > > <type>=<value> > > where <type> MUST be exactly one case-significant character and > <value> is structured text whose format depends on > <type>. In > general, <value> is either a number of fields > delimited by a single > space character or a free format string, and is > case-significant > unless a specific field defines otherwise. Whitespace > MUST NOT be > used on either side of the "=" sign." > > I found that <type> fied should becase sensitive. Bot how about <value>?
That's an interesting question; a quick look through RFC 4566 and RFC 2833 doesn't shed any light on whether 'telephone-event' and 'TELEPHONE-EVENT' should be treated as equivalent or not. However, it certainly seems that it would be safe for an implementation to treat the media format in a case-insensitive manner, since it is quite unlikely that 'telephone-event' and 'TELEPHONE-EVENT' would actually indicate different (and incompatible) formats. -- Kevin P. Fleming Digium, Inc. | Director of Software Technologies Jabber: [email protected] | SIP: [email protected] | Skype: kpfleming 445 Jan Davis Drive NW - Huntsville, AL 35806 - USA Check us out at www.digium.com & www.asterisk.org _______________________________________________ Sip-implementors mailing list [email protected] https://lists.cs.columbia.edu/cucslists/listinfo/sip-implementors
