Definition of a “Link”
Definition of a “Link”
- Define a Link as the Flow of Traffic from One End-Point to the Other
- Changes in Intermediate Network Topology Are Ignored (at present)
- This Throws Away Some Information, But Greatly Simplifies Data Collection and Analysis
- Use ICMP Ping Packets to Measure Availability and Delay
- All Internet Nodes Are Required to Respond to ICMP Ping Packets (Although a Few Sites Block Them)
- Extensive experience shows this to be a reliable measure of performance (although there are known to be problems)
- Response time (RTT), Packet loss, Unreachability (no response to all pings),Unpredictability (variability in response & loss prime time to non-prime)