Bottlenecks and link upgrades

Thu Aug 13 12:01:34 UTC 2020

On 13/Aug/20 13:44, Olav Kvittem wrote:

> sure, but I guess the loss rate depends of the nature of the traffic. 

Packet loss is packet loss.

Some applications are more sensitive to it (live video, live voice, for
example), while others are less so. However, packet loss always
manifests badly if left unchecked.

>> I guess that having more reports would support the judgements better.

For sure, yes. Any decent NMS can provide a number of data points so you
aren't shooting in the dark.

>>
>> A basic question is : what is the effect on the perceived quality of the
>> customers ?

Depends on the application.

Gamers tend to complain the most, so that's a great indicator.

Some customers that think bandwidth solves all problems will perceive
their inability to attain their advertised contract as a problem, if
packet loss is in the way.

Generally, other bad things, including unruly human beings :-).

>>
>> And the relation between that and /5min load is not known to me.

For troubleshooting, being able to have a tighter resolution is more
important. 5-minute averages are for day-to-day operations, and
long-term planning.

>>
>> Actually one good indicator of the congestion loss rate are of course
>> the SNMP OutputDiscards.
>>
>>
>> Curves for  queueing delay, link load and discard rate are surprisingly
>> different.

Yes, that then gets into the guts of the router hardware, and it's design.

In such cases, that's when your 100Gbps link is peaking and causing
packet loss, not understanding that the forwarding chip on it is only
good for 60Gbps, for example.

Mark.