manual config of UE tunnel [RE: 3gpp-analysis: Recommendation on tunneling in the UE]

[Pekka Savola <pekkas@netcore.fi>]

On Tue, 18 Nov 2003, Karim El-Malki (HF/EAB) wrote:
> Let's look at the requirements so as to clarify the issue
> once and for all. The required functions of a mechanism to solve
> this are:
> 
> 1 - The UE gets the IPv4 tunnel endpoint address in the operator's
>     network
> 2 - The UE's IPv4 (probably private) tunnel endpoint address is
>     communicated to the network endpoint
> 3 - The UE gets an IPv6 address known to the network tunnel endpoint

The last part is always a non-issue, as the UE can learn its address by 
a simple RA/RS mechanism, like any other IPv6 interface, so it could be 
dropped from the comparison.
 
> The UE and network tunnel endpoint are within the same IP (L3) domain.

Yes, they are, but they're in different administrative domains.  The 3GPP 
operator must treat the UE as a "hostile" host.  This is entirely 
different from e.g. normal enterprise networks, and which is why ISATAP is 
not very well suited to *this* particular task.

> 2) can't be manually configured (since the UE's address is dynamically
> assigned for most cases) 

Why not?  The 3GPP network has to know the address, because it assigns it 
to the UE.  Why couldn't it communicate it to the IPv6 box somehow?  Or 
where is this information stored, maybe it is retrievable?
 
> Taking the ISATAP example: 1) is solved by using DNS or manual config,
> while 2) and 3) are solved by using the tunneled RA/RS mechanism. This
> requires little work to implement and satisfies the above.

It seems to make that configured tunnels has about equal config for 1) and
3), and making 2) easier should be easily possible because the 3GPP
network must know the addresses of every user involved anyway.

> So it looks to me like ISATAP is not an overkill since it does not
> do more than solve the above and requires little if any config.

This is not accurate, but I'll respond to it in a separate thread.

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