Re: Drops in Core

[William Herrin <bill () herrin us>]

On Sat, Aug 15, 2015 at 1:31 PM, Glen Kent <glen.kent () gmail com> wrote:
> Is there a paper or a presentation that discusses the drops in the core?

Hi Glen,

Probably, but I don't know where to point you.


> If i were to break the total path into three legs -- the first, middle and
> the last, then are you saying that the probability of packet loss is perhaps
> 1/3 in each leg (because the packet passes through different IXes). That
> sounds too aggressive for the middle mile. Dont you think so?

Break it in to five legs:

1. Your immediate last mile
2. The set of networks you directly or indirectly pay to transmit and
receive packets
3. The border link between your networks and the remote user's networks
4. The set of networks the remote user directly or indirectly pays to
transmit and receive packets
5. The remote user's immediate last mile

In some cases, your packets meet on a network which both you and the
remote user pay for. In those cases, leg 3 does not exist. However,
those cases are less common than the one where neither of you pays the
same networks.

Legs 1 and 5 are often over noisy copper wire suspended from a street pole.
Leg 3 is routinely under-provisioned (too little bandwidth for the
traffic demand).
Legs 2 and 4 rarely exhibit loss for long.

Regards,
Bill Herrin


-- 
William Herrin ................ herrin () dirtside com  bill () herrin us
Owner, Dirtside Systems ......... Web: <http://www.dirtside.com/>