Link capacity upgrade threshold

Jack Bates jbates at
Wed Sep 2 14:16:10 UTC 2009

Mikael Abrahamsson wrote:
> If you're dropping packets, you're already over the cliff. Our job as 
> ISP is to forward the packets our customers send to us, how is that 
> compatible with upgrading links when they're so full that you're not 
> only buffering but you're actually DROPPING packets?

Many ISPs don't even watch the dropping rate. Packets can easily start 
dropping long before you reach an 80% average mark or may not drop until 
90% utilization. Dropped packets are a safeguard measurement to detect 
data collision that fills the buffers.

One could argue that setting QOS with larger buffers and monitoring the 
buffer usage is better than waiting for the drop.


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