Abilene Network
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Transcript Abilene Network
Internet2 Measurement
Perspective
Guy T. Almes
Matt Zekauskas
SD Measurement Workshop
June, 1999
General Goal of Internet2
Support advanced applications
• High bandwidth flows
• Low latency
• Low loss
Advanced services
• Multicast
• Quality of service guarantees
‘My application has a problem’
Application, End-host, Network?
Passive measurements could help
divide the problem
Consistent measurements
throughout Internet2 infrastructure
could help diagnose network
problems
Backbone ‘A’
Backbone ‘B’
Backbone ‘A’
Backbone ‘B’
Backbone ‘A’
Backbone ‘B’
Other Measurement Goals
(Forward) network engineering
Enable network research
Feedback to applications
Operational data
• performance, flows, anomalies
Network characterization
• how used? load response? SLS?
Measurement Classification
Utilization [usually SNMP]
Active measurements
• ~Performance (one-way delay, loss,
throughput)
Passive measurements
• ~Traffic characterization
Routing [usually BGP/traceroute]
Utilization
Technically “easy”; “boring”
Coordinate type, frequency
… and reporting
A small number of frequency
multiples
• 15 sec, 1 min, 4 min
Utilization II
Standardize file format
Single access mode
• Example: relative URL for routers
• Example: single I2 measurement page
Active measurements
delay
loss
throughput? (don’t want to interfere
with apps)
my point of view: approximately
Surveyor, +(?) throughput
Packet sizes? Distribution?
Passive Measurements
Question: how apply passive
measurements effectively in a
consistent fashion?
Something that is useful to all?
Each additional probe adds value?
Perhaps flow data
What about packet headers? And
security...
Routing
Can’t just measure one point: policy
E-E measurements:
• surveyor
• AMP
• consistency/access problems a-la
utilization
RA? Routing protocol sniffing?
Traceroute observatories?
Examples
Remote microscope
• UDP, blasting packets
• OCxMON shows more packets than
capacity
Videoconference from Lund to
Pittsburgh
• Packet loss… don’t know why
Desires
Want some way to know where loss
occurs when it happens (or delay)
Advanced service debugging
• Multicast
• QoS (QBone designing measurement
in)
• Service level specification conformance
Desires
Application reflectors along with
routers? (Is this measurement?)
Summary
Consistent measurement of
• Utilization
• Performance
• Traffic Characterization
That are made generally available
In support of applications and the
networks themselves
TM
www.internet2.edu