Subject: RE: 3gpp-analysis-05: miscellaneous non-critical issues

From: Soliman Hesham <[email-masked]>
Date: Sun, 28 Sep 2003 01:19:16 -0400

Comments below.

 > *)
 >     However, the UE may attach to a 3GPP network, in which 
 > the Serving
 >     GPRS Support Node (SGSN), the GGSN and the Home Location Register
 >     (HLR) support IPv4 PDP contexts, but may not support IPv6 PDP
 >     contexts. If the 3GPP network does not support IPv6 PDP contexts,
 >     and an application on the UE needs to communicate with an IPv6(-
 >     only) node, the UE may activate an IPv4 PDP context and 
 > encapsulate
 >     IPv6 packets in IPv4 packets using a tunneling mechanism. 

This
 >     might happen in very early phases of IPv6 deployment. 

=> Please remove this sentence. This is an opinion and does not
apply to the roaming case where the home operator has deployed
IPv6 but the visited operator didn't.

  To 
 > generally
 >     solve this problem (IPv6 not available in the 3GPP network), this
 >     document strongly recommends the 3GPP operators to deploy basic
 >     IPv6 support in their GPRS networks, 

=> This does not apply to the roaming case, so it doesn't solve
the problem stated above.

    which can in most cases be
 >     handled by making software upgrades in the network elements.

=> Please remove this sentence, it's not clear whether this opinion 
(most cases) is based on "most products" or "most deployments".
In any case, many products actually need some HW upgrade depending
on how you define "IPv6 support". There is no need to add this
to a draft.

Hesham

---

From: Pekka Savola <[email-masked]>
Date: Sun, 28 Sep 2003 09:42:41 +0300 (EEST)

Hesham,

Do you have an alternate wording suggestion in mind which would keep the
essence of the original text (including "don't tunnel from UE")?  This
doesn't and is unacceptable to me..

> the problem stated above.

These are two quotes are intentional.  IPv6 support will work when the
visited networks also have upgraded to this minimal IPv6 support.  That's 
also expected to happen during the early phases of transition.  If the 
operator doesn't care about IPv6 users at all, the users can just stay out 
of those networks.

We discussed previously several other options, such as trying to open the
IPv6 PDP context to an operator (if there are many) which in fact supports
IPv6.  This would be useful in the case that 3G + IPv6 gains market
momentum as there are typically multiple networks in a region one could
roam to.  I'm not sure how many of those ended up in the document.

The bottom line is that as we deploy dual stack UE's, when IPv6 isn't
supported in the visited network, one can just use IPv4 if all the tricks
fail.  No tunneling needed at the UE.  Further, tunneling at the UE is 
counter-productive, as it doesn't give the *visited networks* _any_ 
incentive to deploy IPv6 in the first price, which is the number one 
priority.

-- 
Pekka Savola                 "You each name yourselves king, yet the
Netcore Oy                    kingdom bleeds."
Systems. Networks. Security. -- George R.R. Martin: A Clash of Kings