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