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Date:      Tue, 12 May 2015 20:13:27 -0400
From:      "George Neville-Neil" <gnn@neville-neil.com>
To:        "Karlis Laivins" <karlis.laivins@gmail.com>
Cc:        "Eggert, Lars" <lars@netapp.com>, "freebsd-net@freebsd.org" <freebsd-net@freebsd.org>, "grenville armitage" <garmitage@swin.edu.au>
Subject:   Re: Congestion Control Modification
Message-ID:  <7B9881D7-F321-48F8-A38A-7B0D0B147F71@neville-neil.com>
In-Reply-To: <CAF4H_7=fG=izGbqBQ8kY95SW1AXtsfE8%2BafxzWyEdCtRiwv_pA@mail.gmail.com>
References:  <CAF4H_7mSGp_GZGaDBx8xq47FY1j85xLHq%2BZY1jMzprbzp%2Bg9zw@mail.gmail.com> <5535945F.90504@swin.edu.au> <CAF4H_7nOJP=Wy7LJSBi2PGupnMMvZu0xYeT2iYjhKDg-DPC6fw@mail.gmail.com> <F572540B-45C8-4EBF-9E18-7CA7E30CFD0C@neville-neil.com> <CAF4H_7=WZTmNUaS9x0DJh1YNRzFCJPbqJ_eFp12=z8snvTpn3g@mail.gmail.com> <98E7D40A-EC37-413D-85CE-2A6012811E08@netapp.com> <CAF4H_7=uV8ng-%2BY93wR88-aeW19HabaqR0iVkDXf6yujE4Wbpw@mail.gmail.com> <8D3AEF2A-1413-4C44-9E5C-66900847F18A@neville-neil.com> <CAF4H_7=fG=izGbqBQ8kY95SW1AXtsfE8%2BafxzWyEdCtRiwv_pA@mail.gmail.com>

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Sounds good.

Best,
George

On 1 May 2015, at 1:21, Karlis Laivins wrote:

> Hello George,
>
> Thank you for the tip! I have set up a virtual test environment with 
> IMUNES
> (interesting tool, by the way) and now I am running validation tests, 
> to
> see, if the results there are at least similar to those that can be
> achieved on a physical testbed.
>
> I will let you know if and when the implementation will be done as I 
> will
> certainly need objective feedback.
>
> BR,
> Karlis
>
> On Fri, May 1, 2015 at 12:06 AM, George Neville-Neil 
> <gnn@neville-neil.com>
> wrote:
>
>> If you want to run some experiments, though, you could look at 
>> running PTPd
>> on 3 servers (master, and two slaves) which will get you decent
>> synchronization
>> among the three.  Where decent is less than the typical RTT of a TCP
>> packet on a
>> 1Gbps LAN.
>>
>> Best,
>> George
>>
>>
>> On 30 Apr 2015, at 14:48, Karlis Laivins wrote:
>>
>> Yes, you are correct, I meant to write "relative OWD". As David Hayes 
>> put
>>> it - "Relative OWD measurements are easier, and clock drift is not 
>>> usually
>>> a problem over the time it takes to send and receive an ACK".
>>>
>>> Thank you for the correction!
>>>
>>> On Thu, Apr 30, 2015 at 4:19 PM, Eggert, Lars <lars@netapp.com> 
>>> wrote:
>>>
>>> On 2015-4-30, at 15:04, Karlis Laivins <karlis.laivins@gmail.com> 
>>> wrote:
>>>>
>>>>> I have yet to solve the issue of
>>>>> how to get the One Way Delay for the ACK message (the time it 
>>>>> takes ACK
>>>>>
>>>> to
>>>>
>>>>> arrive from receiver of the ACK'ed data sender) correctly.
>>>>>
>>>>
>>>> That won't work without synchronized clocks, which you can't really
>>>> assume
>>>> to be present.
>>>>
>>>> Lars
>>>>
>>>



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