Subject: [Softwires] FW: New Version Notification for draft-lee-softwire-6rd-udp-01

From: "Lee, Yiu" <[email-masked]>
Date: Sat, 29 May 2010 11:18:11 -0400

Hi all,

We posted a updated version of "UDP Encapsulation of 6rd". This version
changed the design significantly. This is the list of changes:

1. Removed the stateful requirement in the 6rd BR.
2. Embedded the UDP port info the v6 address.
3. No control protocol is required.
4. The encapsulation is stateless and very much align with the class 6rd.
5. This requires no change in the home gateway, so the starting cost of 6rd
will be lower.
6. Starting cost is lower so it should speedup the 6rd deployment.
7. Minimal change in the 6rd BR so same 6rd BR can be used for both classic
and udp encap. 
8. Added a new co-author.

However, there are some drawbacks required further discussion in the working
group. Two most important design decisions are:

1. How to discover 6rd parameters? ISP relies on radius can pass the
parameters over the existing infrastructure. However, ISP relies on dhcp may
require some OOB discovery procedure.

2. Since the 6rd udp host is behind NAT, so it won't know the NAT-ed udp
port after NAT-ing. We solve this problem by asking the 6rd BR to fill in
the port information. However, this design virtually creates a NAT66
scenario.

Our goal for this technology is promoting IPv6 even in the situation where
the ISP doesn't manage the home gateway. This is a low cost add-on to the
class 6rd and help the ISP to transition to IPv6 in a faster pace.

Questions and comments are welcome.

Yiu

------ Forwarded Message
From: IETF I-D Submission Tool <[email-masked]>
Date: Thu, 27 May 2010 19:44:15 -0700
To: Yiu Leung Lee <[email-masked]>
Cc: <[email-masked]>
Subject: New Version Notification for draft-lee-softwire-6rd-udp-01

A new version of I-D, draft-lee-softwire-6rd-udp-01.txt has been
successfully submitted by Yiu Lee and posted to the IETF repository.

Filename:  draft-lee-softwire-6rd-udp
Revision:  01
Title:   UDP Encapsulation of 6rd
Creation_date:  2010-05-28
WG ID:   Independent Submission
Number_of_pages: 15

Abstract:
This memo specifies the UDP encapsulation to IPv6 Rapid Deployment
(6rd) protocol which enables hosts behind unmodified Home Gateway
device to access 6rd service.

The IETF Secretariat.

------ End of Forwarded Message

---

From: Timothy Baldwin <[email-masked]>
Date: Mon, 31 May 2010 08:45:19 +0100

, Yiu wrote about draft-lee-softwire-6rd-udp-01:

> parameters over the existing infrastructure. However, ISP relies on dhcp
> may require some OOB discovery procedure.

See my draft:
http://www.ietf.org/id/draft-baldwin-dhc-softwire-anycast-dhcp-00.txt

> the port information. However, this design virtually creates a NAT66

The BR should inform the host what port number is being used.

A potential problem is that it uses a lot of address space, a /48 per IPv4 
address. It also lacks the direct peer to peer communication that is 
possible using 6RD, 6to4 and Teredo.

Would the server model be popular enough to justify the use of large 
amounts of address space? Could not DHCPv6 be used to allocate address to 
the hosts?

Two alternative approaches, use a well known destination port combined port-
forwarding configured using UPnP, NAT-PMP or manually. This has the same 
address efficiency as classical 6RD.

Or use a /64 prefix like Teredo, using 48 bits for the IPv4 address and 
port, leaving 14 bits to address local hosts, but I expect such use to be 
uncommon. There would need to be a protocol to find a shorter route perhaps 
transversing NATs, behind the same NAT, or perhaps native on the same link. 
The border router remains stateless.

> class 6rd and help the ISP to transition to IPv6 in a faster pace.

Potentially too fast, if a large portion of ISPs deploy it then the client 
is deployed by an automatic update. There would need be some rules to make 
the deployment gradual.