Subject: [Tsvwg] SCTP Clarification

From: [email-masked]
Date: Tue, 12 Nov 2002 11:51:40 -0500

Could someone please clarify coding of the Parameter Type Field of variable
length/optional parameters in RFC 2960.

According to Section 3.2.1 the two most significant bits of the Parameter
Type Field are used to indicate treatment  if the parameter is
unrecognized.  However, it is not clear whether coding of the two most
significant bits is included in optional parameter defined in RFC 2960.
For example, in the INIT chunk, the optional parameter IPv4 is specified as
Parameter Type  "Type 5."  Does this mean that the two most significant
bits are coded "00" for value Type 5, or coding of the two most significant
bits is implementation dependent?

Thanks
Ray

_______________________________________________
tsvwg mailing list
[email-masked]
https://www1.ietf.org/mailman/listinfo/tsvwg

---

From: [email-masked]
Date: Fri, 15 Nov 2002 05:20:23 +0200

Hi Ray!

	See my coment below...

> -----Original Message-----
> From: ext [email-masked] [mailto:[email-masked]]
> Sent: 12 November, 2002 18:52
> To: [email-masked]
> Subject: [Tsvwg] SCTP Clarification
> 
> 

	"Type 5" means "Type 0x0005", so the first two bits are "00". For example, Parameter Type 0xC005 corresponds to "Success Indication" (AddIP draft).

	All the chunks and parameters defined in the base specification have their first two bits (of the Type field) set to 0. This means in fact that all the implementations should recognize them (since they must be compliant with the specification of SCTP), otherwise they (datagrams or chunks) should be dropped and in the case of parameters in INIT/INIT ACK this would mean that an association could never be established...

	I hope this helps!

	BR Iván Arias Rodríguez