Subject: other comments on draft-nielsen-v6ops-3GPP-zeroconf-goals-00.txt

From: Alain Durand <[email-masked]>
Date: Thu, 04 Nov 2004 22:47:08 -0800

Direct tunneling:
-----------------------
I would have like this document to take a stance with regard to direct  
tunneling.
Is it needed or not? I found section 3.2 confusing:

 > 3.2. IPv6 tunnel link characteristics, Scope and Limitations:
 >
 >   Direct tunneling is neither an explicit goal nor explicitly excluded
 >   in Zero-Configuration Tunneling in the 3GPP network environment.

Specially when later, section 9.3 says:
 > 9.3. Implications of Direct Tunneling
 >
 >   In case direct tunneling in between end-hosts is provided by the
 >   tunneling protocol, it will not (as described in Section 9.2.1) be
 >   possibly for end-hosts to filter out received Protocol-41
 >   encapsulated packets based on whether the IPv4 source is an address
 >   belonging to a trusted Tunnel Server as such behavior evidently  
would
 >   break direct tunneling.
 >
 >   As other end-hosts generally are non-trusted, direct tunneling may
 >   thus open up for attacks against IPv6 ingress filtering.

The logical conclusion of section 9.3 seems to be that for security  
reasons,
direct tunneling should not be allowed and thus be a non goal of this  
document...
Unless, of course, there is a strong rationale for direct tunneling  
that should be spelled out
in section 3.2

Tunnel end-point discovery
-------------------------------------
This document should also reference
http://www.ietf.org/internet-drafts/draft-yamamoto-naptr-service- 
discovery-00.txt

No support for PAN
--------------------------
 > 3.1. IPv6 address allocation, Scope and Limitations:
 >
 >   The primary goal of 3GPP Zero-Configuration Tunneling is to provide
  >  IPv6 connectivity to nodes on an individual basis. By this it is
  >  meant that it is only an explicit goal to have a /128 address
  >  allocated for global connectivity on the tunnel link. As such  
optimal
  >  IPv6 connectivity provisioning in Personal Area Network (PAN)
  >  scenarios is not explicitly within the scope of Zero-Configuration
  >  Tunneling.

What does the phrase "optimal IPv6 connectivity provisioning in PAN"  
means?
The word 'optimal' confuses me...

I find this section a bit restrictive, as it is not difficult to design  
a zeroconf mechanism
that will enable prefix delegation with a simple router advertisement  
sent over the tunnel.
Also, this is a violation of RFC3177 which recommends allocation a /64  
to cell phone
especially in order to support PAN...
I would like to see at least better rationale why PAN support is not  
deemed important
or why it would introduce unjustifiable complexity.

Timing (section 5)
---------
Although I understand very well that time to market is the essence of  
this work
and this is good background information, section 5 should be removed  
from the final
document.

	- Alain.