Hi Jerry,

isn't this the problem statement of Conex?

Again, you at the end host would gain little insight with Conex, but every 
intermediate network operator can observe the red/black marked packets, compare 
the ratios and know to what extent (by looking at ingress vs egress into his 
network ) he is contributing...

Best regards,
  Richard

  ----- Original Message ----- 
  From: Jerry Jongerius 
  To: 'Rich Brown' 
  Cc: [email protected] 
  Sent: Thursday, August 28, 2014 6:20 PM
  Subject: Re: [Bloat] The Dark Problem with AQM in the Internet?


  It add accountability.  Everyone in the path right now denies that they could 
possibly be the one dropping the packet.

   

  If I want (or need!) to address the problem, I can't now.  I would have to 
make a change and just hope that it fixed the problem.

   

  With accountability, I can address the problem.  I then have a choice.  If 
the problem is the ISP, I can switch ISP's.  If the problem is the mid-level 
peer or the hosting provider, I can test out new hosting providers.

   

  - Jerry

   

   

   

  From: Rich Brown [mailto:[email protected]] 
  Sent: Thursday, August 28, 2014 10:39 AM
  To: Jerry Jongerius
  Cc: Greg White; Sebastian Moeller; [email protected]
  Subject: Re: [Bloat] The Dark Problem with AQM in the Internet?

   

  Hi Jerry,

   

    AQM is a great solution for bufferbloat.  End of story.  But if you want to 
track down which device in the network intentionally dropped a packet (when 
many devices in the network path will be running AQM), how are you going to do 
that?  Or how do youpropose to do that?

   

  Yes, but... I want to understand why you are looking to know which device 
dropped the packet. What would you do with the information?

   

  The great beauty of fq_codel is that it discards packets that have dwelt too 
long in a queue by actually *measuring* how long they've been in the queue. 

   

  If the drops happen in your local gateway/home router, then it's interesting 
to you as the "operator" of that device. If the drops happen elsewhere (perhaps 
some enlightened ISP has installed fq_codel, PIE, or some other zoomy queue 
discipline) then they're doing the right thing as well - they're managing their 
traffic as well as they can. But once the data leaves your gateway router, you 
can't make any further predictions.

   

  The SQM/AQM efforts of CeroWrt/fq_codel are designed to give near optimal 
performance of the *local* gateway, to make it adapt to the remainder of the 
(black box) network. It might make sense to instrument the CeroWrt/OpenWrt code 
to track the number of fq_codel drops to come up with a sense of what's 
'normal'. And if you need to know exactly what's happening, then 
tcpdump/wireshark are your friends. 

   

  Maybe I'm missing the point of your note, but I'm not sure there's anything 
you can do beyond your gateway. In the broader network, operators are 
continually watching their traffic and drop rates, and adjusting/reconfiguring 
their networks to adapt. But in general, it's impossible for you to have any 
sway/influence on their operations, so I'm not sure what you would do if you 
could know that the third router in traceroute was dropping...

   

  Best regards,

   

  Rich



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