I also agree this is a very nice piece of work. The current title is
"Implementing AplusP in the provider's IPv6-only network". I think this
not only covers "Implementing AplusP in an IPv6-only network", but also
captures very important information about the port usage in various
applications. I would like to see the draft to expand to include more
popular applications and OS, and the radio between port usage and number
of sessions. By reading Fig. 3 and Fig. 4 in
http://opensourcev6transtechnologies.weebly.com/experiments-results.html,
the radio is roughly 1 to 4. These experiments give concrete results to
operators to plan for any port-sharing technology.

Cheers,
Yiu


On 8/10/11 8:38 AM, "Rajiv Asati (rajiva)" <[email protected]> wrote:

>Xiaohong,
>
>Your work is very insightful. Thanks for pointing it out.
>
>In your experimentation, did you use 'consecutive' port-set or
>'scattered' port-set or both? If just the former, then is it possible to
>experiment using 'scattered' port-set?
>
>Cheers,
>Rajiv
>
>
>> -----Original Message-----
>> From: [email protected] [mailto:xiaohong.deng@orange-
>> ftgroup.com]
>> Sent: Wednesday, August 10, 2011 5:35 AM
>> To: [email protected]; Rajiv Asati (rajiva)
>> Cc: [email protected]
>> Subject: RE: [Softwires] Clarification of the stateles/stateful
>>discussion
>> 
>> 
>> 
>> |-----Original Message-----
>> |From: Rémi Després [mailto:[email protected]]
>> |Sent: Wednesday, August 03, 2011 4:02 PM
>> |To: Rajiv Asati (rajiva)
>> |Cc: [email protected]
>> |Subject: Re: [Softwires] Clarification of the
>> |stateles/stateful discussion
>> |
>> |
>> |Le 3 août 2011 à 00:39, Rajiv Asati (rajiva) a écrit :
>> |
>> |> Satoru-san,
>> |>
>> |> This is an important point that most of us forget that
>> |restricting to
>> |> "n" ports doesn't equate to just "n" NAT sessions rather many more
>> |> than n sessions. We must add that to the 4v6 motivation
>> |draft as well
>> |> as to the 4v6 comparison draft.
>> |
>> |+1
>> 
>> +1. Session number are usually many more than ports number.
>> 
>> We tested port and sessions assumptions of applications on the A+P NAT,
>> which has been documented in A+P experiments draft, to investigate how
>> many ports and sessions they are costing on the NAT mapping table
>>dynamically
>> from the first NAT bindings being established to the last one being
>> destroyed.
>> 
>> Some results below:
>> 
>> Usually, apps consume some more sessions than ports, and for the P2P
>>apps,
>> sessions
>> number could even be as a couple of times as ports number.
>> 
>>  For example, BitTorrent established five hundreds of sessions while
>>the port
>> consumption
>>  was under a hundred in the first minute of the communication, because
>>when
>> BitTorrent
>> initiates a downloading, it first uses the same source port to connect
>>to the
>> different destinations
>> (destination IP and port) therefore one source port multiplexing
>>different
>> sessions. Skype is
>>  another example that uses one source port to  multiplex different
>>sessions
>> thereby saving
>> source port consumptions on NAT.
>> 
>>  For exact figures of ports/session number for apps, see my page:
>>  
>>http://opensourcev6transtechnologies.weebly.com/experiments-results.html
>> The session consumption comparison among the same set of applications is
>>  illustrated in Figure 4.
>> 
>> Xiaohong
>> 
>> 
>> |
>> |RD
>> |
>> |>
>> |>> port. There may be multiple session to different destinations using
>> |> the same
>> |>> external port. The 900G figure is valid, as long as internal hosts
>> |> reuse the
>> |>> same source address+port for different destinations.
>> |>
>> |> Cheers,
>> |> Rajiv
>> |>
>> |>
>> |>> -----Original Message-----
>> |>> From: [email protected] [mailto:[email protected]]
>> |> On Behalf
>> |>> Of Simon Perreault
>> |>> Sent: Tuesday, August 02, 2011 9:55 AM
>> |>> To: [email protected]
>> |>> Subject: Re: [Softwires] Clarification of the stateles/stateful
>> |> discussion
>> |>>
>> |>> Simon Perreault wrote, on 08/02/2011 09:24 AM:
>> |>>> Satoru Matsushima wrote, on 08/01/2011 10:41 PM:
>> |>>>> Thanks, a clarification has made to clear a confusion of
>> |restricted
>> |> port
>> |>>>> set/ranges and NAT session table limitation. Even if a CPE is
>> |> allocated 256
>> |>>>> ports, NAT session can be made over 900G sessions in theory.
>> |> ('2^32'<Full
>> |>>>> 32bits v4 address> - '2^29'<class-D/E> - '2^7'<0/8,127/8>) *
>> |> 2^8<256
>> |>> ports>.
>> |>>>
>> |>>> This is only true for endpoint-dependent NATs, which are forbidden
>> |> by the
>> |>> BEHAVE
>> |>>> RFCs (4787 and 5382). According to these RFCs, NATs MUST have
>> |>>> endpoint-independent mapping behaviour. This means that each NAT
>> |> session
>> |>> will
>> |>>> consume one external port.
>> |>>
>> |>> Sorry, I confused the terminology. Each NAT *binding* will consume
>> |>> one external port. There may be multiple session to different
>> |>> destinations using
>> |> the same
>> |>> external port. The 900G figure is valid, as long as internal hosts
>> |> reuse the
>> |>> same source address+port for different destinations.
>> |>>
>> |>> Simon
>> |>> --
>> |>> DTN made easy, lean, and smart --> http://postellation.viagenie.ca
>> |>> NAT64/DNS64 open-source        --> http://ecdysis.viagenie.ca
>> |>> STUN/TURN server               --> http://numb.viagenie.ca
>> |>> _______________________________________________
>> |>> Softwires mailing list
>> |>> [email protected]
>> |>> https://www.ietf.org/mailman/listinfo/softwires
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>> |> Softwires mailing list
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>> |
>> |
>> |
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