Another LTE network turns up as IPv4-only

Tore Anderson tore.anderson at redpill-linpro.com
Thu Oct 11 09:09:35 UTC 2012


* Mikael Abrahamsson

> On Thu, 11 Oct 2012, Tore Anderson wrote:
> 
>> That some features are available only on the most advanced access
>> technology is perfectly reasonable and to be expected, IMHO. If not,
>> what's the point of upgrading at all?
> 
> Uh, whut? I expect my ssh sessions to survive a 4G->3G handover, and if
> they happen to go over IPv6, I want them to survive.

In my experience, long-lived sessions are unreliable when you're on the
move anyway. Go into an elevator? Sessions drop. Subway heads into a
tunnel? Sessions drop. Get in range of a known WiFi network? Sessions
drop. If you want to make an app for mobile, you better be able to
recover. So for me, this is hardly a concern. Still, I'll grant you that
you that you and I might have different priorities here.

I think this is a really poor excuse for not supporting IPv6 and IPv4v6
in any case. Unless I'm gravely misinformed on how 3GPP mobile networks
work, there is absolutely no reason why you cannot on LTE simultaneously
support IPv4, IPv6, and IPv4v6. That the LTE network additionally
supports IPv6/IPv4v6 does not *in any way* prevent you from sticking to
IPv4 in all cases and enjoying the exact same session mobility between
2G/3G/4G as you can if the LTE network only supports IPv4.

The session mobility problem will not go away completely by upgrading
the 2G/3G part of the network, too. As I understand it, there's no
shortage of devices on the market that only supports IPv6 on LTE, but
not on 3G. Apple's iPhones and iPads, for example. So while it won't be
the network's fault, it doesn't really matter - from the end users's
point of view, the exact same thing will happen.

Besides, the LTE network is being touted as a potential replacement for
wired broadband. In that use case, the end user isn't likely to be
mobile at all - presumably he'll have some CPE sitting in his window
sill within LTE coverage 100% of the time. So no session mobility
issues, and all the potential to be provisioned with IPv6 access. But no.

> The important reason to upgrade is to get higher speeds, not to get
> access to new L3 tech.

Missed opportunity if you ask me. We could have had both.

>> I lose my YouTube streams when I get handed over from 3G to 2G, too,
>> for example. I can live with that. I much prefer it to YouTube not
>> working 3G as well, even though that might very well be considered a
>> more "consistent" user experience.
> 
> I don't agree with you at all. I don't believe I would lose the stream
> when doing that handoff in our network, it might buffer some more
> (because EDGE is slower than HSDPA), but you wouldn't lose the stream.

I'm not watching a YouTube stream to see a still frame with a
"buffering..." animation on top, so if I roam into 2G while watching
something, I'll be putting my phone away anyway. Whether or not I
actually lose the TCP connection is besides the point, the application
is useless anyway.

-- 
Tore Anderson
Redpill Linpro AS - http://www.redpill-linpro.com



More information about the NANOG mailing list