Hi Ralph,
More in line.

Le 12 août 2010 à 08:06, Rémi Després a écrit :

> 
> Le 12 août 2010 à 00:00, Ralph Droms a écrit :
> 
>> Rémi - please see responses in line...
>> 
>> - Ralph
>> 
>> On Aug 11, 2010, at 8:38 AM 8/11/10, Rémi Després wrote:
>> 
>>> 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.)
>> 
>> traffic to IPv6 servers just bypasses dual-stack lite altogether, right, so 
>> the limitation doesn't apply to that traffic?

Exactly.
Thus, dual-stack hosts will need time less and less IPv4 ports.
Suggesting in an RFC that they may need over time several thousands IPv4 ports 
would therefore be misleading.

>> 
>>> 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). 
>> 
>> Agreed; one could argue that even sharing an IPv4 address among 5 customers 
>> allows 5x as many customers in the existing IPv4 address assignment, which 
>> should be more than enough to bridge the gap until IPv6 is available.
>> 
>>> 3. Where applicable static sharing is much simpler to operate.
>> 
>> Agreed.
>> 
>>> If the principle is agreed, I can propose detailed words myself to improve 
>>> the draft.

Is it right, then, that you welcome the proposal to revise the text?

Regards,
RD


>>> 
>>> 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
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>>> https://www.ietf.org/mailman/listinfo/softwires
>> 
> 


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