Re: Teredo vs Silkroad

[JF Tremblay <jean-francois.tremblay@hexago.com>]

--On May 21, 2004 2:31 PM +0800 rengrong wang <rengronw@usc.edu> wrote:

> Hi,
>
> In draft-liumin-v6ops-silkroad-01.txt it is said that Silkroad wants to
> enable nodes located behind one or several IPv4 NATs to obtain IPv6
> connectivity and it seems like a tunnel-broker solution.  It is known
> that Teredo is a automatic tunnel mechanism that figures out the same
> problem.
>
> What's the difference between Silkroad and Teredo?

IMHO, Silkroad is simply another protocol based on tunnel broker/server 
model (RFC3053) with an optimization to make two hosts on the same link 
realize they can talk directly. Teredo on the other hand allows hosts 
implementing a Teredo client to exchange directly through NATs, except 
symmetric ones. However traffic to hosts not implementing a Teredo client 
must go through a relay.

At first sight, Silkroad doesn't seem to offer any significant improvement 
over TSP, except the nodes-on-same-link optimization. Both support NAT 
traversal with any type of NAT, including nested ones. However TSP doesn't 
require the use of a web page, offers prefix delegation, authentication and 
has a solid experimental background since it's been deployed for over 5 
years to more than 100000 users.

The question sparking in my mind from this is whether of not the detection 
of two tunneled hosts on the same link would be a desirable feature to 
include in the tunnel broker model. It involves the broker telling a host 
what is the public IPv4 address and port of another host, which may be a 
security issue. However with Teredo this information is already included in 
the IPv6 address, so I guess it would provide the same level of security.

> Best regards,
>
> Crisy(Rengrong) Wang
> =======================================
> USC,EE-Systems

Jean-Francois Tremblay
Hexago
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