[e2e] Header length field in IP header

Joe Touch touch at ISI.EDU
Thu Sep 23 11:18:41 PDT 2004

I'm not advocating for not creating new services.

I don't see any utility to using "unused bits" in IPv4, which aren't 
actually unused so much as 'declared invalid', vs. just changing the IP 
version number, adding an option, or any of a dozen other more 
conventional ways.

The key here is that using these unused bits doesn't buy anything; if 
packets that don't know this mod will drop the bits, then why not just 
use an IP option? or a new version that has IPv4 with another 32 bits, 
all for Diff Serv?


Saad Biaz wrote:

> On Thu, 23 Sep 2004, Joe Touch wrote:
>>The best part of that is the packets will be dropped by all intervening
>>routers, since they're not "unused" but rather "errors to drop", which
>>means you'll get the diff serv you deserve ;-)
> Joe:
> I wonder if we would have trains today if engineers reacted as you are
> doing now. If someone proposed to use trains in the 18th century,
> you would tell him: "Where would you use trains? there are no tracks".
> ----------------------------------------------------------------------
> Saad Biaz, Ph.D., Assistant Prof.     Voice: (334) 844 6307
> 114 Dunstan Hall Auburn University    Fax  : (334) 844 6329
> Auburn, AL 36849-5347, USA            http://www.eng.auburn.edu/~sbiaz
> ----------------------------------------------------------------------
-------------- next part --------------
A non-text attachment was scrubbed...
Name: signature.asc
Type: application/pgp-signature
Size: 254 bytes
Desc: OpenPGP digital signature
Url : http://www.postel.org/pipermail/end2end-interest/attachments/20040923/c9cb452a/signature.bin

More information about the end2end-interest mailing list