Comcast IPv6 Trials

Richard Barnes richard.barnes at
Thu Jan 28 12:47:02 UTC 2010

What I've heard is that the driver is IPv4 exhaustion: Comcast is
starting to have enough subscribers that it can't address them all out
of 10/8 -- ~millions of subscribers, each with >1 IP address (e.g.,
for user data / control of the cable box).

On Thu, Jan 28, 2010 at 12:55 AM, Kevin Oberman <oberman at> wrote:
>> Date: Wed, 27 Jan 2010 20:59:16 -0800
>> From: "George Bonser" <gbonser at>
>> > -----Original Message-----
>> > From: William McCall
>> > Sent: Wednesday, January 27, 2010 7:51 PM
>> > Subject: Re: Comcast IPv6 Trials
>> >
>> > Saw this today too. This is a good step forward for adoption. Without
>> > going too far, what was the driving factor/selling point to moving
>> > towards this trial?
>> SWAG: Comcast is a mobile operator.  At some point NAT becomes very
>> expensive for mobile devices and it makes sense to use IPv6 where you
>> don't need to do NAT.  Once you deploy v6 on your mobile net, it is to
>> your advantage to have the stuff your mobile devices connect to also be
>> v6.  Do do THAT your network needs to transport v6 and once your net is
>> ipv6 enabled, there is no reason not to leverage that capability to the
>> rest of your network. /SWAG
>> My gut instinct says that mobile operators will be a major player in v6
>> adoption.
> SWAG is wrong. Comcast is a major cable TV, telephone (VoIP), and
> Internet provider, but they don't do mobile (so far).
> --
> R. Kevin Oberman, Network Engineer
> Energy Sciences Network (ESnet)
> Ernest O. Lawrence Berkeley National Laboratory (Berkeley Lab)
> E-mail: oberman at                  Phone: +1 510 486-8634
> Key fingerprint:059B 2DDF 031C 9BA3 14A4  EADA 927D EBB3 987B 3751

More information about the NANOG mailing list