Maintaining a Healthy Network Infrastructure

Here are some key points to consider when maintaining/designing/upgrading a network infrastructure..

01. All Ethernet segments should be switched (no Hubs)
02. All Ethernet segments utilization should be below 40%
03. Collisions should be less than 0.1% over 5 minute intervals for Ethernet segments
04. Multicast or Broadcast traffic should be less than 20% for any segment
05. Number of output queue drops should not exceed 100 in an hour
06. Number of input queue drops should not exceed 50 in an hour
07. Number of buffer misses should not exceed 25 in an hour
08. Number of ignored packets should not exceed 10 in an hour
09. Cyclic Redundancy Check (CRC) should be less than 1 per million bytes of data for any segment
10. WAN link utilization should be below 70%
11. WAN response time should be less than 100 ms
12. CPU utilization for any device should be below 75%
13. One-way Delay for voice traffic should be less than 150 ms
14. One-way Delay for video traffic should be within 200 ms - 400 ms
15. Jitter for voice traffic should be less than 30 ms
16. Jitter for video traffic should be within 30 ms - 50 ms
17. Loss for both voice and video traffic should be less than 1%