In practice, this is not really a problem. Hosts typically do not originate IP packets larger than 1500 bytes. And second, a survey has been taken (from a list of ISPs, see Acknowledgement section) where nearly all ISP link MTUs are either 4470 bytes or supportEthernet jumbo frames of 9000 bytes. Therefore, we don't anticipateany problems with prepending additional headers.
What this really presupposes is that all ITR/ETRs will end up at large service provider sites.
If an ITR/ETR ends up as a CE device or embedded in a larger site, then I don't see how this
claim holds. Tony -- to unsubscribe send a message to rrg-request@psg.com with the word 'unsubscribe' in a single line as the message text body. archive: <http://psg.com/lists/rrg/> & ftp://psg.com/pub/lists/rrg