Running Strict QoS Causes Packet Loss Elsewhere

[mhoppes]

So here's a really weird one....

I have a Netonix switch on which I have a customer throttled to 10megabits in and 10megabits out via Strict QoS. (Port A)

I started seeing bizarre packet loss on ANOTHER switch port. ( Port B)

Finally, tracked it down that when the inbound (UDP) traffic to this customer on the Port A port would exceed 10 megabits (20-25 UDP is what I saw) the switch would start dropping packets to Port B.

When the traffic dropped to below 10 megabits the packet loss to Port B would stop. When I dropped the QoS on Port A the issues on Port B all went away.

So it gets even more strange... if I take traffic shaping off of the port, the port runs along around 300kbps (it's a radio station audio feed). The moment I put traffic shaping on (in this case I upped it to 30 megabits) it starts churning along around 10-15 megabits/second. Take QoS off and it drops back down to 300kbps.... something is very weird here.

I even tried moving this one microwave to a different switch port and the issue continued to follow the microwave (Port B)

Additionally, when this fired off it would cause huge amounts of errors on Port Bs interface.



What might be going on here?