Re: draft-arkko-ipv6-transition-guidelines WGLC

[Mikael Abrahamsson <swmike@swm.pp.se>]

On Fri, 20 Aug 2010, Cameron Byrne wrote:

> And, as i have pointed out before in various forums, today's 3G networks 
> require 2x the signalling and packet core cost for dual stack users (2x 
> bearers, 2x mobility events, 2x many things ...).  Yes, the costs change 
> in LTE .... LTE will not be mainstream before IPv4 Exhaust.

I would like to question the 2x cost.

Yes, multi-bearer per user license cost money, so does handling 2x numbers 
of bearer, but the number of packets isn't going to be 2x so actual packet 
moving hw won't be even close to 2x cost. More license, more 
HLR/MME/SPGW/GGSN/SGSN signalling, but not more packets.

I also don't really see how LTE changes things dramatically in this 
aspect, to enable roaming we're going to be stuck at GTPv1 bearers for the 
forseeable future (IMHO), so we're still going to have to do 2x PDP 
context for users with IPv4 and IPv6 dual stack.

It might even be that ds.lite with ipv6 only to the phone makes more sense 
here because I'd imagine that enables roaming with single PDP 
context/bearer instead of multiple, and I'd imagine the roaming network 
doesn't really care if the user has IPv4 or IPv6? I'm not a roaming expert 
though, might be wrong.

--
Mikael Abrahamsson    email: swmike@swm.pp.se