Drops in Core

Tue Aug 18 02:38:47 UTC 2015

On Mon, Aug 17, 2015 at 1:44 PM, Scott Whyte <swhyte at gmail.com> wrote:
>
>
> On 8/15/15 09:47, Glen Kent wrote:
>>
>> Hi,
>>
>> Is it fair to say that most traffic drops happen in the access layers, or
>> the first and the last miles, and the % of packet drops in the core are
>> minimal? So, if the packet has made it past the first mile and has
>> "entered" the core then chances are high that the packet will safely get
>> across till the exit in the core. Sure once it gets off the core, then all
>> bets are off on whether it will get dropped or not. However, the key point
>> is that the core usually does not drop too many packets - the probability
>> of drops are highest in the access side.
>
>
> What do these terms mean in a world where my EC2 VM talks to my GCE VM?  It
> doesn't seem unreasonable that the DC bandwidth on either end dwarfs the
> "core" capacity between the two.

there's some other work going on:
  <http://www.bitag.org/documents/BITAG_Press_Release_-_Announcing_Prioritization_and_Differential_Treatment_Topic.pdf>

which pokes a bit at this idea of packet drops (from the 'what if I
prioritize traffic? or differentiate between traffic types?'
perspective). I imagine that a topic of conversation is that: "hey, do
we get meaningful drop numbers, or does prioritization/differentiation
matter, in the core of a network or only at the network edges?"

mostly bitag is focused on 'consumer' edges, so they may not look at
'inside a a datacenter' problems.