Mobile Measurements Flashcards
1
Q
Why do we want to measure?
A
Operations: Keep internet efficiently running
Research: Understand the internet
Engineering: support protocol design decisions
User: comparing, limited troubleshooting
2
Q
What do we measure?
A
- Network performance (path capacity, latency, loss)
- Network structure (topology, routers, caches, nats)
- Application-specific performance (web, VoIP, p2p)
- Anomalies
- Instant values, trends
3
Q
What are issues with active and passive measurement?
A
Passive:
- collecting data w/ potentially high rate
- does the data reveal right information at right time?
- Repeatability
- Privacy
Active:
- Measuring meaningful metrics
- Impact of measurement
- Impact of the additional measure traffic
- Reresentative?
4
Q
Name 3 active and 3 passive measurement sources
A
Passive: Logs, network management, sniffing traffic
Active: Tool-based traffic generator/measurement: ping, trace route, iperf
5
Q
What is Jitter?
A
It is the variability of one-way delay -> Known delta for regular packet transmissions
