Since the subject of interoperability was brought up, I couldn't resist this thought.
In a lot of deployed protocols out there from IETF, or ITU telephony protocols, or cable docsis protocol, there is one common thread. For core protocol messages and message headers, the messages are defined in a specific format that is NOT TLV based. The first reason is because one wants interoperability for the core protocol messages. One also does not want a new message proposed every day from someone's backyard. Since, by deliberation, the core protocol messages do not follow a TLV format, it is hard for the standard to change in a heartbeat without proper thinking. I feel the EH in IPv6 is such a core header. I don't want IPv6 to be that flexible that folks grow a new EH in their backyard and start developing products with the new EH. I raise the point again on another question. How many new EH's have been defined new in the past decade that one needs a flexible format for EH? Further, even I don't have a strong opinion on the TLV format proposed in this draft nor do I have a big problem with it. But I do have some basic questions and issues raised above. Lastly, let's get to the root cause of what needs fixed and stay focused on that problem and its solution - as one can see, using a TLV based format for EH doesn't fix the problem. As Markku asked, how does one know the EH is unknown for a node to even skip such an EH? Thanks. Hemant -----Original Message----- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Brian E Carpenter Sent: Thursday, March 20, 2008 4:57 PM To: Suresh Krishnan Cc: ipv6@ietf.org Subject: Re: Review comments for draft-krishnan-ipv6-exthdr-01.txt >> It was not my intention to >> specify any skip/drop behavior on the nodes. But that's exactly what IETF specs should always do, to promote interoperability. Even if the recommended behaviour is silent discard, that should always be specified IMHO. Brian -------------------------------------------------------------------- IETF IPv6 working group mailing list ipv6@ietf.org Administrative Requests: https://www.ietf.org/mailman/listinfo/ipv6 -------------------------------------------------------------------- -------------------------------------------------------------------- IETF IPv6 working group mailing list ipv6@ietf.org Administrative Requests: https://www.ietf.org/mailman/listinfo/ipv6 --------------------------------------------------------------------
