Subject: Re: comments on protocol draft

From: "Khosravi, Hormuzd M" <[email-masked]>
Date: Fri, 16 Jul 2004 18:38:41 -0700

Great question, Joel!

We tried doing some experiments using DCCP for data and TCP for control,
however we did not find any stable implementation for DCCP in the Linux
Kernel with CCID 2 (TCP like congestion control). The implementation
that we found had problems when we started increasing the data rate. But
I am discussing this with some folks in DCCP WG (copied in this email)
and hopefully with their help, we will be able to work out a robust
solution soon.

Regards
Hormuzd

-----Original Message-----
From: Forwarding and Control Element Separation
[mailto:[email-masked]] On Behalf Of Joel M. Halpern
Sent: Friday, July 16, 2004 5:43 PM
To: [email-masked]
Subject: Re: [FORCES] comments on protocol draft

If we pretend for the moment that it is advanced enough to be
applicable,
do your results tell us anything about what happens if we use TCP for
Control and DCCP for data packets between the FE and the CE?

Thank you,
Joel

At 05:28 PM 7/16/2004 -0700, Khosravi, Hormuzd M wrote:
>Furquan,
>
>Yes, we have done a study using different transport connections as well
>as using prioritization in addition to different transports. A brief
>summary of the results is as follows...
>
>1. Using separate congestion/flow aware transport protocol connections
>for data and control helps significantly in case of DoS attacks (we
used
>TCP for both)
>2. Using prioritization of control messages over data messages, further
>helps improve control connection performance during a DoS attack
>So we would propose using a combination of the two to provide
robustness
>during a DoS attack.
>
>Side Note- Using a combination of congestion aware and unaware
>transports such as TCP and UDP for Control and Data doesn't work very
>well, even with prioritization, cause the TCP traffic is easily
>overwhelmed with UDP during an attack. (This is similar to the results
>shown by Weiming during the last IETF meeting.)
>
>Thanks
>Hormuzd

---

From: "Khosravi, Hormuzd M" <[email-masked]>
Date: Fri, 16 Jul 2004 19:03:53 -0700

Yes we tried this one, there were some problems, I don't exactly
remember...
The one that we finally landed using was
http://www.cs.utexas.edu/~arun/linux-2.4.20.tgz

Thanks for the pointer though,

Regards
Hormuzd

-----Original Message-----
From: Jamal Hadi Salim [mailto:[email-masked]] 
Sent: Friday, July 16, 2004 6:50 PM
To: Khosravi, Hormuzd M
Cc: [email-masked]
Subject: Re: comments on protocol draft

Hormuzd,
did you see this:
http://www1.ietf.org/mail-archive/web/dcp/current/msg00074.html

cheers,
jamal