- From: Adrien de Croy <adrien@qbik.com>
- Date: Fri, 30 Jan 1998 10:09:19 +1200
- To: Ben Laurie <ben@algroup.co.uk>
- Cc: http-wg@cuckoo.hpl.hp.com
Hi At 18:21 29/01/98 +0000, Ben Laurie wrote: >Adrien de Croy wrote: >> A proposal for the end tag could be say a 4 byte magic number. So there >> would be a 1 in 4 billion chance of there being a natural conflict caused by >> a premature close on the connection with the last 4 bytes of the last packet >> being the magic number. If this were thought too risky, simply increasing >> the length would serve to render this event less likely. > >That's a pretty dodgy bit of maths. What you mean is that for any >particular 4-byte sequence there's a 1 in 4 billion chance, so in 1 MB >of data, the probability is (roughly) 1 in 4000. Or, over a 64 kb/s link >at full capacity, about one mistake a week. > I would have thought that in a random data stream, the chances of any particular 4 byte sequence would have been 1 in 4 Billion, but we are only looking at the last 4 bytes before a close. So, given there is only one close per session, there is only one inspected 4 byte sequence, hence the chance of any one file causing confusion over an OEF marker is 1 in 4 billion. However, as pointed out by John Franks, this method would not, and cannot allow for multiple transactions per connection, since it relies on the close event being a signal as well. However, reflecting more on that issue, the chances of a client requiring multiple created entitities (i.e those where the server cannot know a priori the size) in a single connection is rather low, at least at the moment. Multiple normal requests per connection would still be possible, and unaffected by this proposal. >Cheers, > >Ben. > >-- >Ben Laurie |Phone: +44 (181) 735 0686|Apache Group member >Freelance Consultant |Fax: +44 (181) 735 0689|http://www.apache.org >and Technical Director|Email: ben@algroup.co.uk |Apache-SSL author >A.L. Digital Ltd, |http://www.algroup.co.uk/Apache-SSL >London, England. |"Apache: TDG" http://www.ora.com/catalog/apache > ---------------------------------------------------------------------------- ------ Adrien de Croy - adrien@qbik.com. Qbik New Zealand Limited, Auckland, New Zealand See our pages and learn about WinGate at http://www.qbik.com/ ---------------------------------------------------------------------------- ------
Received on Thursday, 29 January 1998 13:18:27 UTC