PacketShaper causing slowness or performance issues, how to confirm.

Products

• PacketShaper S-Series

Issue/Introduction

When PacketShaper is busy/has high CPU usage or has restrictive policies and partitions or has NIC issues, it could cause slowness on the network communication. For that reason, when there is slowness in network, one may suspect it is due to the PacketShaper. However, the slowness may not always be due to PacketShaper, it may be due to something else. 

Resolution

In order to confirm if the slowness is due to PS or not, here is what you can do:

1. Check CPU usage, 'sys health'. If the PS is very busy then it could introduce latency.

2. You can try 'setup shaping off' - if this helps then either the box is overloaded due to shaping or shaping Policies and Partitions are causing the slowness. Try to check Policies and Partitions are not too restrictive. Check CPU usage with shaping ON vs OFF. If you have too many Rate Policies, Partitions, Dynamic Partitions, then it could add to the CPU load.

3. If the above doesn't help, you can try 'setup shaping passthru'; this will keep the NIC or the link up but all PS functionality will be bypassed (no classification, shaping, reporting). The PS will act as a Switch. This should fix any PacketShaper overload issues.

4. If the above doesn't fix the issue then it could be NIC related. You check 'net nic' output for any NIC related errors (e.g. CRC, frame, etc.). NIC setting/speed/duplex/negotiation and compatibility issues could cause this issue.

5. Please do not do this unless you have Serial Console connection available:

'setup shaping bypass' - PacketShaper will go to bypass mode, NIC will go down. The internal SW will directly talk to the Router (PacketShaper becomes a wire). Once you issue this command, you will lose SSH or WUI access so you will need Serial Console connection to recover. From Serial Console CLI - You can do 'setup shaping off' or 'setup shaping on' to go back to original state.

If none of the above helps, we can confirm that the slowness is not due to PacketShaper.