RE: Review on draft-ietf-v6ops-v6-in-mobile-networks-03

[Tina Tsou <[e-mail]>]

Hi Rajeev,
See comments in line.


We keep our promises with one another - no matter what!

Best Regards,
Tina TSOU
http://tinatsou.weebly.com/contact.html


-----Original Message-----
From: Rajeev Koodli [mailto:[e-mail]] 
Sent: Tuesday, March 01, 2011 1:55 PM
To: Tina TSOU; [e-mail]; 'The IESG'; [e-mail]
Cc: [e-mail]
Subject: Re: Review on draft-ietf-v6ops-v6-in-mobile-networks-03


Hi Tina,

Thanks for the review.

On 3/1/11 8:25 AM, "Tina TSOU" <[e-mail]> wrote:

> Comment #1
> In section 3.1, "Delaying the public IPv4 address exhaustion involves
> assigning private IPv4 addressing for end-users, as well as extending an
> IPv4 address (with the use of extended port ranges).
>  
>>> do you mean using some solution like address + port
> (http://tools.ietf.org/html/draft-ymbk-aplusp-09)?
>      If yes, where do you think Address + Port solution should be
> implemented? Maybe one of the node could be GGSN/PDN gateway, how about
the
> other node, is it the mobile node or the ANG?


My personal opinion is that you would have to modify the MN.

It is not the intent of the ID to suggest location of A+P elements, as you
probably realize.

[Tina: 
Some clarification of A+P used in mobile network is needed. A+P can be used
on CPE in wireline network. There is no very proper node to support in
wireless network. Implementing A + P in cell phone may need change of
Operating System, even though not as much as PNAT. In addition, there maybe
some ARP issue, for example, cell phones sharing one address can not
communicate with each other, as the peer address is it self's, unless we are
going to change ARP.]

>  
>  
> Comment #2
> In section 3.1
> "An approach to  address this problem is to make the always-on PDN to be
> IPv6, and
>    enable IPv4 PDN on-demand, e.g., when an application binds to an IPv4
>    socket interface. This ensures that an IPv4 address is not assigned
>    for every attached MN, but only to those attempting to use the
>    traffic.  The IPv4 PDN may be subject to session idle timers upon the
>    expiry of which, the PDN (and the assigned IPv4 address) may be
>    deleted.  Another option specified in the 3GPP standards is to defer
>    the allocation of IPv4 address on a dual-stack IPv4v6 PDN at the time
>    of connection establishment.  This has the advantage of a single PDN
>    for IPv6 and IPv4, along with deferring IPv4 address allocation until
>    an application needs it"
>  
>>> now, and in the near future, most of the content would still be
available
> in IPv4 network, not sure whether this solution could save private IPv4
> address.

Sure. However, by deferring the allocation of an IPv4 address until a PDN
and/or an application actually needs it, you also conserve the pool.
[Tina: 
it could work, which won't save many private IP address. It will also bring
the complexity of implementation.]

>     And this would also require some modification in the mobile devices.

Right. The operators who are interested in this already have the necessary
"bindings" - when a user clicks on an app (that requires IPv4 PDN), it
invokes the necessary PDN signaling if the PDN is not active already.

Regards,

-Rajeev


> 
> 
> We keep our promises with one another - no matter what!
> 
> Best Regards,
> Tina TSOU
> http://tinatsou.weebly.com/contact.html
> 
> 
>