Subject: Re: Extended seq number
From: Stephen Kent <[email-masked]>
To: Ramana Yarlagadda <[email-masked]>
Cc: [email-masked]
Date: Tue, 23 Apr 2002 16:08:27 -0400

At 12:05 PM -0700 4/23/02, Ramana Yarlagadda wrote:
>Hi, All
>
>I am going thruough the Draft-ietf-ipsec-esp-v3-02.txt.
>
>1)  Extended Sequence number is of 64bits (optioanally) and  the ICV 
>is calucluated over the entire 64bits.but the sequence number 
>transmitted  is of 32 bits , to keep the overhead low.
>
>Because of  this requirement  implementaion becomes quite complex, 
>at least not straight forward.  what  we frame (IPSec header) is 
>different from what we send.
>
>
>-cheers
>-ramana

The high order 32 bits of the ESN are appended to the packet 
specifically to make it easier to strip them prior to transmission. 
I don't know how to make it easier, and still not send the extra bits.

Steve