Helo all,

Sec 8.4.1 says (asterisks added):
"... thousands or tens of thousands of ports could be use in a peak by any 
single customer browsing a number of AJAX/Web 2.0 sites.  
As such, service providers allocating a fixed number of ports per user should 
dimension the system with a minimum of N = several thousands of ports for every 
user.  This would bring the address space reduction ratio to a single digit.  
Service providers using a smaller number of ports per user (N in the hundreds) 
should expect customers applications to break in a more or less random way over 
time.
In order to achieve higher address space reduction ratios, *it is recommended 
that service provider do not use this cookie-cutter approach, and, on the 
contrary, allocate ports as dynamically as possible, just like on a regular 
NAT*."

This is more biased against fixed number of ports per customer than technically 
appropriate, at least for the three reasons below. (Besides, such a bias isn't 
needed to justify the DS-lite specification): 

1. The text should take into account that "over time" more and more servers 
will have IPv6, and that the full 64K ports are available in IPv6. (The 
mentioned AJAX/Web 2.0 sites would typically enable IPv6 asap, if not done yet. 
This will prevent problems over time.)

2. If the number of assignable IPv4 addresses is for a start multiplied by 10, 
by statically sharing ports of each address among 10 customers, this still 
leaves several thousands of IPv4 ports per customer. (Exactly 6144 ports per 
customer if, as appropriate, the first 4K ports, that include well-known ports 
and have special value are excluded). 

3. Where applicable static sharing is much simpler to operate.

If the principle is agreed, I can propose detailed words myself to improve the 
draft.

Regards,
RD
 

Le 11 août 2010 à 00:30, [email protected] a écrit :

> A New Internet-Draft is available from the on-line Internet-Drafts 
> directories.
> This draft is a work item of the Softwires Working Group of the IETF.
> 
> 
>       Title           : Dual-Stack Lite Broadband Deployments Following IPv4 
> Exhaustion
>       Author(s)       : A. Durand, et al.
>       Filename        : draft-ietf-softwire-dual-stack-lite-06.txt
>       Pages           : 34
>       Date            : 2010-08-10
> 
> This document revisits the dual-stack model and introduces the dual-
> stack lite technology aimed at better aligning the costs and benefits
> of deploying IPv6 in service provider networks.  Dual-stack lite
> enables a broadband service provider to share IPv4 addresses among
> customers by combining two well-known technologies: IP in IP (IPv4-
> in-IPv6) and Network Address Translation (NAT).
> 
> A URL for this Internet-Draft is:
> http://www.ietf.org/internet-drafts/draft-ietf-softwire-dual-stack-lite-06.txt
> 
> Internet-Drafts are also available by anonymous FTP at:
> ftp://ftp.ietf.org/internet-drafts/
> 
> Below is the data which will enable a MIME compliant mail reader
> implementation to automatically retrieve the ASCII version of the
> Internet-Draft.
> <Pièce jointe Mail>_______________________________________________
> Softwires mailing list
> [email protected]
> https://www.ietf.org/mailman/listinfo/softwires


_______________________________________________
Softwires mailing list
[email protected]
https://www.ietf.org/mailman/listinfo/softwires

Reply via email to