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Re: IPv6 MTU issues in FTTH applications

2002-02-22 16:20:03
In message <IEEOIFENFHDKFJFILDAHKELDDNAA(_dot_)alh-ietf(_at_)tndh(_dot_)net>, 
"Tony Hain" writes
:
n the example here in particular, putting voice over
large packets is intuitively the wrong thing to do, and making those
frames larger than 1500 simply makes the problem worse. 

It's not just intuitive, it's quantitative.  If you're doing 
uncompressed voice (compression makes this effect worse), a 1500 byte 
packet holds 214 ms of voice at the (U.S.) standard rate of 56K bps.  
That's already beyond the delay budget, just for that one hop, and 
without taking into account the jitter buffer, speed of light delay, 
etc.


                --Steve Bellovin, http://www.research.att.com/~smb
                Full text of "Firewalls" book now at http://www.wilyhacker.com