Re: [multipathtcp] Two proxy scenario (network proxy off path)

[Christoph Paasch <[e-mail]>]

On 29/03/17 - 15:42:59, Henderickx, Wim (Nokia - BE/Antwerp) wrote:
> Christoph, yes but again it something new and less optimal from the proposed MP_CONVERT IE in the SYN.

No, that's what I wrote below. It's not less optimal. It's exactly the same in
terms of performance as MP_CONVERT IE in the SYN!


Christoph


> 
> On 29/03/2017, 10:39, "[e-mail] on behalf of Christoph Paasch" <[e-mail]> wrote:
> 
>     Hello Wim,
>     
>     inline:
>     
>     On 29/03/17 - 15:29:04, Henderickx, Wim (Nokia - BE/Antwerp) wrote:
>     > Phil, you will be a bit more optimal but not a lot as you can see or you end up changing the SOCKs protocol. Even if you do this MP_CONVERT IE will always be the most optimal and hence this is what we propose for doing this proxy function.
>     > 
>     > On 29/03/2017, 10:12, "multipathtcp on behalf of [e-mail]" <[e-mail] on behalf of [e-mail]> wrote:
>     > 
>     >     By non-chatty, I meant a version that didn't do all the authentication messages. After all, the home gateway and network proxy can be expected to know about each other already - at least don't need to do for every new TCP connection from devices behind home gateway
>     >     
>     >     -----Original Message-----
>     >     From: [e-mail] [mailto:[e-mail]] 
>     >     Sent: 29 March 2017 06:30
>     >     To: Eardley,PL,Philip,TUB8 R <[e-mail]>; [e-mail]
>     >     Subject: RE: Two proxy scenario (network proxy off path)
>     >     
>     >     Hi Phil, 
>     >     
>     >     Can you please clarify what you mean by a "non-chatty version"? version of what?
>     >     
>     >     You can refer to Section 3 of RFC1928 to have an idea about the number of messages that are required before sending actual traffic when SOCKSv5 is used. 
>     >     
>     >     Below an excerpt of signaling messages observed to create an initial subflow using SOCKSv5:
>     >     
>     >     ==============
>     >     (MP Client) ->    TCP SYN    ->  (MCP)
>     >                        <- TCP SYN/ACK <- 
>     >                        ->    TCP ACK    ->
>     >                        -> SOCKS Method Request (1)(a) ->
>     
>     you would of course use TFO with SOCKS, so that you gain one RTT.
>     
>     If then in addition to that you remove the authentication part of SOCKS, and
>     you can even put the payload right after the SOCKS Connection Request inside
>     the SYN-payload, then you are effectively also at a 0-RTT connection
>     establishment.
>     
>     
>     Christoph
>     
>     
>     >                        <-    TCP ACK (b)   <-
>     >                         <- SOCKS Method Response (2)(c) <-
>     >                         ->   TCP ACK (d)   ->
>     >                         -> SOCKS Authentication Request (3)(e) ->
>     >                         <-    TCP ACK (f)    <-
>     >                         <- SOCKS Auth. Response (4)(g) <-
>     >                         ->   TCP ACK (h)   ->
>     >                         -> SOCKS Connection Request (5)(i) -> (MCP)
>     >                         <-   TCP ACK (j)                   <- (MCP)
>     >                                                               (MCP)  -> TCP SYN (k) -> (Server)
>     >                                                               (MCP)  <- SYN/ACK (l) <- (Server)
>     >                         <- SOCKS Connection Response (n) (6) <-(MCP) -> TCP ACK (m) -> (Server)
>     >                         ->   TCP ACK (o)  ->
>     >     =================
>     >     
>     >     I let you compare it with the 0-RTT and 0-extra signaling approach with MP_CONVERT IE. 
>     >     
>     >     Cheers,
>     >     Med
>     >     
>     >     > -----Message d'origine-----
>     >     > De : multipathtcp [mailto:[e-mail]] De la part de 
>     >     > [e-mail] Envoyé : mardi 28 mars 2017 20:24 À : 
>     >     > [e-mail] Objet : [multipathtcp] Two proxy scenario 
>     >     > (network proxy off path)
>     >     > 
>     >     > Hi,
>     >     > 
>     >     > I'm now thinking about the scenario where there are two proxies, one 
>     >     > in the home gateway or Customer Premises Equipment and one in the 
>     >     > network, both under the control of the operator. And looking at the 'explicit mode'
>     >     > scenario, which - if I get it right - means that the network proxy is 
>     >     > not on the default path. (It's safe to assume that the home gateway 
>     >     > proxy is on the default path)
>     >     > 
>     >     > Thinking about the use of SOCKS in this context.
>     >     > 
>     >     > Earlier Olivier said (in the context of the smartphone scenario -  
>     >     > sorry if your comments don't apply to this scenario and I'm just 
>     >     > creating
>     >     > confusion) that there are different variants of SOCKS that can be 
>     >     > used, which mainly depend on the number of messages that are used to 
>     >     > authenticate.
>     >     > In the two proxy scenario, it's probably reasonable to assume that the 
>     >     > home gateway and network proxy are already authenticated. So a 
>     >     > non-chatty version would be ok.
>     >     > 
>     >     > Is that right?
>     >     > 
>     >     > Thanks
>     >     > phil
>     >     > 
>     >     > _______________________________________________
>     >     > multipathtcp mailing list
>     >     > [e-mail]
>     >     > https://www.ietf.org/mailman/listinfo/multipathtcp
>     >     
>     >     _______________________________________________
>     >     multipathtcp mailing list
>     >     [e-mail]
>     >     https://www.ietf.org/mailman/listinfo/multipathtcp
>     >     
>     > 
>     > _______________________________________________
>     > multipathtcp mailing list
>     > [e-mail]
>     > https://www.ietf.org/mailman/listinfo/multipathtcp
>     
>