I disagree. The driver wont be by customers at all - they don't care abut transit, only the applications that use the transit. Lets say in two years time the cost to get new IPv4 address space rises to US$10k per /24 per month. Is the service provider going to want to pay this, or migrate to free IPv6 space? The cost of not migrating is going to be huge. Service providers need to make sure they are deploying kit now that is IPv6 capable, and making implementation decisions that will assist with the IPv6 migration. Potentially the issue of multihoming and mobile IPv6 is going to be very taxing on current equipment. -----Original Message----- Here is an interesting presentation by Robert Rockell of Sprint about IPv6: http://www.nanog.org/mtg-0405/pdf/rockell.pdf . Slides 5, 7, 9, and 10 are very valid as to why this is unlikely for a few more years to come. The major driver will be customer demand (read: $$$$), or the network operators themselves finding resource shortages are impacting on their operations, thus moving to a v4-over-v6 core. That said, Sprint do offer semi-native v6 transit, and I believe UUNET also.