[144306] in North American Network Operators' Group
RE: NAT444 or ?
daemon@ATHENA.MIT.EDU (Leigh Porter)
Thu Sep 8 04:47:47 2011
From: Leigh Porter <leigh.porter@ukbroadband.com>
To: Owen DeLong <owen@delong.com>
Date: Thu, 8 Sep 2011 08:48:16 +0000
In-Reply-To: <4A76411A-509E-411A-B230-F2176793DCB7@delong.com>
Cc: NANOG <nanog@nanog.org>
Errors-To: nanog-bounces+nanog.discuss=bloom-picayune.mit.edu@nanog.org
> -----Original Message-----
> From: Owen DeLong [mailto:owen@delong.com]
> Sent: 08 September 2011 01:22
> To: Leigh Porter
> Cc: Seth Mos; NANOG
> Subject: Re: NAT444 or ?
>=20
> > Considering that offices, schools etc regularly have far more than 10
> users per IP, I think this limit is a little low. I've happily had
> around 300 per public IP address on a large WiFi network, granted these
> are all different kinds of users, it is just something that operational
> experience will have to demonstrate.
> >
> Yes, but, you are counting individual users whereas at the NAT444
> level, what's really being counted is end-customer sites not individual
> users, so the term
> "users" is a bit misleading in the context. A given end-customer site
> may be from 1 to 50 or more individual users.
Indeed, my users are using LTE dongles mostly so I expect they will be sin=
gle users. At the moment on the WiMAX network I see around 35 sessions fro=
m a WiMAX modem on average rising to about 50 at peak times. These are a c=
ombination of individual users and "home modems".
We had some older modems that had integrated NAT that was broken and locke=
d up the modem at 200 sessions. Then some old base station software died a=
t about 10K sessions. So we monitor these things now..
>=20
> > I would love to avoid NAT444, I do not see a viable way around it at
> the moment. Unless the Department of Work and Pensions release their /8
> that is ;-)
> >
>=20
> The best mitigation really is to get IPv6 deployed as rapidly and
> widely as possible. The more stuff can go native IPv6, the less depends
> on fragile NAT444.
Absolutely. Even things like google maps, if that can be dumped on v6, it'=
ll save a load of sessions from people. The sooner services such as Micros=
oft Update turn on v6 the better as well. I would also like the CDNs to be=
able to deliver content in v6 (even if the main page is v4) which again w=
ill reduce the traffic that has to traverse any NAT.=20
Soon, I think content providers (and providers of other services on the 'n=
et) will roll v6 because of the performance increase as v6 will not have t=
o traverse all this NAT and be subject to session limits, timeouts and suc=
h.
--
Leigh
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