Loss measure in Argus

[Carter Bullard]

Hey Can Desem,
If you can, upload to ftp://qosient.com/incoming, that would be  
great!!!!

Carter

On Aug 10, 2009, at 1:48 AM, Desem, Can wrote:

>
> I am using the latest versions; argus-3.0.1.beta.5 and argus- 
> clients-3.0.2.beta.10
>
> Where should I upload the files? The two will come to about 1.1Mbytes.
>
> Regards
> Can Desem
>
> -----Original Message-----
> From: Carter Bullard [mailto:carter at qosient.com]
> Sent: Monday, 10 August 2009 3:38 PM
> To: Desem, Can
> Cc: argus-info at lists.andrew.cmu.edu
> Subject: Re: [ARGUS] Loss measure in Argus
>
> Hey C.Desem,
> Seems that tcptrace() is also giving poor results.  If the transmitter
> retransmits
> 255 packets, then the receiver should be able to report this same
> number or
> at least something very close.  At least that is the goal of Argus's
> loss reporting.
>
> Argus counts loss in a number of ways, including tracking ack sequence
> numbers, but being an order of magnitude off is indeed incorrect.
>
> Can you share the packet files that show this?  I'll use to debug the
> reports.
> What version of argus are you using?
>
> Carter
>
> On Aug 10, 2009, at 1:19 AM, Desem, Can wrote:
>
>> Hi Carter
>>
>> The manual on ra says that the "loss" measure shows "pkts
>> retransmitted or dropped". It should probably also include out of
>> order packets.
>> Here are the results of a simple tcp transmission experiment between
>> a source and destination pc. All the packets are captured at both
>> ends by tcpdump and then used for analysis;
>>
>> Argus/ra shows 255 lost packets (sloss)  at the transmitter end
>> (tcptrace gives 255 retransmitted packets).
>>
>> Argus/ra shows 3016 lost packets (sloss) at the receiver end
>> (tcptrace gives 3016 out of order packets and 1 retransmitted  
>> packet).
>>
>> Clearly, at the receive end one will typically see the retransmitted
>> packets as out of order packets and this number will be much higher
>> than the number of the actual retransmitted packets. Therefore it is
>> important to indicate this in the manual since one may mistakenly
>> assume that the "loss" value is a direct indication of the
>> retransmitted or dropped packets. Alternatively would it be possible
>> to have separate measures for retransmitted and out-of-order packets
>> as is the case in "tcptrace" ?
>>
>> I checked this since I could not believe that the throughput could
>> be so high given the high packet drop rate (initially collecting at
>> the receive end only)
>>
>> Regards,
>>
>> C.Desem
>>
>>
>>
>>
>>
>>
>>
>>
>
>

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