Example: Congested Link
Detecting that a link is congested
- Utilization statistics every five minutes from SNMP
- Active probes suffer degraded performance
- Customers complain
Reasons why the link might be congested
- Increase in demand between some set of source-destination pairs
- Failed router/link in our network causes change in our routes
- Failure or policy change in another ISP changes traffic flow
How to determine why the link is congested?
How to relieve the congestion on the link?