Re: [v6ops] draft-ietf-v6ops-mobile-device-profile last call

[Lorenzo Colitti <[e-mail]>]

On Mon, Feb 23, 2015 at 11:42 PM, Mikael Abrahamsson <[e-mail]>
wrote:

> "should". So as far as I can tell, the current document we're discussion
>> is saying the same thing as 3GPP 23.401. The behaviour is also what I have
>> seen from "all" UEs I did testing with, so I'd say the baseband vendors are
>> doing just this.
>>
>
I stand by my earlier questions. Do we have evidence that people do this in
production? It's not just the money - Dual-PDP is either a 100% increase or
a 50% increase in state and signaling load over single-PDP. It also has
worse fate-sharing properties (e.g., IPv4 can fail but IPv6 can be working,
and vice versa). Is that something we want to recommend?

I get it that if you're an operator, the ideal situation is that you have a
knob to control every possible aspect of device behaviour, even if you
never use it. But forget about that for a moment. Remember, this group is
about providing *operational guidance*. Is this really something you would
recommend operationally? If so, why?

Saying "establishing a second PDP context after code 52 is what the 3GPP
standards say the device should do" is all very well. But it's not really
very useful for the IETF to say that, first because those standards are
already written down in other organizations' documents, and second because
(as you yourself point out) the terminals *do* respect the standards and
already behave this way.