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

[<juha.wiljakka@nokia.com>]

Andreas,

I'm glad to get more operator comments on the v6ops mailing list; thanks for your comments! Some short replies below.

-----Original Message-----
From: ext [mailto:Andreas.Schmid1@swisscom.com]
Sent: 02 October, 2003 09:55

Well, let's add a comment from an operator here...

Here are some facts:
- Today's 2.5/3G networks are running on IPv4.
- Today's economic situation is quite difficult.
- Nobody operating a network wants to touch a running system if not
absolutely necessary.

It is therefore very much needed to think about a phased introduction of
IPv6. It is just _not_ realistic to think of a direct move from IPv4 to
native IPv6 - let's make this clear here!

Operators _need_ mechanisms to introduce IPv6 in phases. A first phase
should be fully non-intrusive, cheap but still secure. Tunneling from
the UE (e.g. using ISATAP) seems to perfectly be suited to meet these
requirements. 

I expect the v6ops WG to write guidelines that help the operators in the
introduction of IPv6 in their networks. Such guidelines just have to
consider a phased introduction. Everything else is just not realistic
and not of use for operators. I am looking forward to such documents
from this group.

JW: I know that the current situation is not an easy one. And I fully agree that the principle of phased IPv6 induction is correct.

I can also see that IPv6 can be tested / demonstrated etc. using tunneling in the UE. But putting basic IPv6 support in the GPRS network is not that difficult. IPv6 support in a GPRS nw includes (at least) the following points:

* Upgrading (a) GGSN to support IPv6 PDP contexts (that basically means dual stack support in the GGSN). This is only needed on the "upper IP layer" / user layer in the 3GPP architecture. Network layer (below GTP tunnels) can still be IPv4. See RFC3314, Figure 2.
* SGSN should support IPv6 PDP context signalling (especially if charging is considered..), i.e. it must be possible to activate an IPv6 PDP context.
* HLR support for IPv6
* IPv6 Access Point Names should also be configured to the packet core DNS
* you also might want to put up a (configured) IPv6-in-IPv4 tunnel from the GGSN e.g. to the IPv6 island (can be in the operator's network or elsewhere) that provides IPv6 services
* IPv6 capable firewall can also be considered

According to my current understanding, the above does not require big investments and in many cases software upgrades are sufficient.

Furthermore, introducing (some) IPv6 support in the network does not cause problems with the current IPv4 network, i.e. IPv6 can be run simultaneously without disrupting IPv4 traffic! This is not a 3GPP-specific thing; this is one of the good sides of the dual stack deployment. There is no need to immediately move from native IPv4 to native IPv6 support in the cellular networks.

Best Regards, 
		-Juha W.-