Docstoc

Internet2

Document Sample
Internet2 Powered By Docstoc
					Abilene Measurements & Observatory ;
End-to-End Performance Initiative
     Matt Zekauskas, matt@internet2.edu
     Senior Engineer
      Backbone Network Infrastructure
      End-to-end Performance Initiative

Presentation to Comcast
29-September-2003
       Abilene Measurements


Taken for multiple reasons
  • Operations (including support of E2EPI)
  • Engineering
  • Research
Basic assumption: all measurements
available
  • Some restrictions for privacy concerns

               Comcast: Abilene Measurements & End-to-End Performance   29-Sep-2003   2
       Measurement Capabilities

• Four dedicated servers at each node
   – Provision for additional servers in the future
   – Local data collection to capture data at times of network
     instability
   – CDMA device provides GPS-synchronized time signals
• Measurements
   – One way latency, jitter, loss
   – Regular TCP/UDP throughput tests – ~1 Gbps
   – SNMP (NOC) [octets, packets, errors; collected every 3 sec]
   – Netflow (ITEC Ohio) [anonymized by 0-ing last 11 bits]
   – Multicast beacon with historical data
   – Routing data (BGP & IGP) [IGP still under development]
   – Optical splitter taps on backbone links at select location(s)
• Management Platform with extended access
   – Publicly available, including `Router Proxy’: query directly
                    Comcast: Abilene Measurements & End-to-End Performance   29-Sep-2003   3
        Abilene Observatory


A program to provide enhanced support of
computer science research over Abilene
1) Access to network data archive
  • Correlated Database
  • Support from and for graduate programs
2) Provision for direct network measurement
and experimentation
  • Resources reserved for additional servers
     – Power (DC), rack space (2RU), router uplink ports
       (GigE)
  • Initial deployment is PlanetLab
                    Comcast: Abilene Measurements & End-to-End Performance   29-Sep-2003   4
         URLs


http://abilene.internet2.edu/observatory
   • Pointers to all measurements/sites/projects
http://www.abilene.iu.edu/
   • NOC home page. Weathermap, Proxy, SNMP
     measurements
http://netflow.internet2.edu/weekly/
   • Summarized flow data
http://www.itec.oar.net/abilene-netflow/
   • “Raw” -- matricies
                   Comcast: Abilene Measurements & End-to-End Performance   29-Sep-2003   5
      The E2EPI Mission


To enable the researchers, faculty,
students and staff who use high
performance networks to obtain optimal
performance from the current
infrastructure on a consistent basis.

     Raw                                   Applications
  Connectivity                             Performance
              Comcast: Abilene Measurements & End-to-End Performance   29-Sep-2003   6
The “Wizard Gap”




     Comcast: Abilene Measurements & End-to-End Performance   29-Sep-2003   7
        A Broad Problem Space


Application                           Network
                                              • Configuration
Hardware                                              – Duplex mismatch
  • Memory                                            – Asymmetry
  • Bus                                               – Limits
                                                      – Firewalls
  • Network Interface
                                              • Hardware problems
OS                                                    – Electronics
  • IP Stack                                          – Dirty fiber

  • Tuning                                    • Congestion
  • Internal structure                … and others!
                   Comcast: Abilene Measurements & End-to-End Performance   29-Sep-2003   8
        Role of Internet2


Work on holes
Provide central support where it makes sense,
for example
  • Backbone viewpoints, architecture: “piPES”
  • Central knowledge repository
Help with path problems, connection with
University/Gigapop networking personnel



                 Comcast: Abilene Measurements & End-to-End Performance   29-Sep-2003   9
       Host/OS Tuning: Web100
       (member work)

Goal: TCP stack, tuning not bottleneck
Large measurement component
  • TCP performance not what you expect?
    Ask TCP why!
     –Receiver bottleneck (out of receiver window)
     –Sender bottleneck (no data to send)
     –Path bottleneck (out of congestion window)
     –Path anomalies (duplicate, out of order, loss)
www.web100.org, also www.net100.org
                 Comcast: Abilene Measurements & End-to-End Performance   29-Sep-2003   10
        Reference Servers / Beacons


(TCP) Performance debugging
  • Conjecture: 80% of problems related to
     – Host tuning (mostly buffers)
     – Duplex mismatch [path]
     – Other physical connection problem [path]
     – NDT: http://miranda.ctd.anl.gov:7123/
H.323 conferencing
  • Goal: portable machines that tell you if system
    likely to work (and if not, why?)
     – http://e2epi.internet2.edu/Beacon/BeaconOverview.html
     – ViDeNet Scout, http://scout.video.unc.edu/

                    Comcast: Abilene Measurements & End-to-End Performance   29-Sep-2003   11
       Putting It All Together


Imagine three levels of instrumentation
  • The previously described Abilene servers
  • Servers installed by gigaPoPs and
    Campuses, at very well connected points
    in their network
  • Software that can run on users’ machines
    or portable testing machines
Divide and Conquer
               Comcast: Abilene Measurements & End-to-End Performance   29-Sep-2003   12
         Putting It All Together


Tests are made routinely among the Abilene
machines
Tests are made occasionally from Abilene
machines to the well-connected gigaPoP
machines and Campus machines.
To evaluate performance, look at results of
“routine” tests in addition to tests that start at
the users, or the portable machine.

                  Comcast: Abilene Measurements & End-to-End Performance   29-Sep-2003   13
                       Putting It All Together


                                                                                             Wall Jack


                GigaPoP A
                              Backbone 1
                                                                                      Campus
                                                                                                      P
P
      Campus                 Backbone 2
                                                                     GigaPoP B


    Wall Jack


                             Comcast: Abilene Measurements & End-to-End Performance     29-Sep-2003   14
        E2E piPES


• Project: End-to-End Performance Initiative
Performance Environment System (E2E
piPES)
• Goal: To allow end-users and network
operators to determine performance
capabilities, locate problems, and contact the
right person to get a problem resolved.
• Approach: Collaborative project combining
the best work of many organizations, including
DANTE/GEANT, NLANR/DAST, SLAC, UCL,
etc.
                Comcast: Abilene Measurements & End-to-End Performance   29-Sep-2003   15
       E2Epi Work


piPES architecture
One-way measurement tools
For intermediate servers
  • Scheduling
  • Database
  • Authentication
Export data via web service
                Comcast: Abilene Measurements & End-to-End Performance   29-Sep-2003   16
        E2Epi Work


Understand applications and their
performance requirements
   • Technical Advisory Group
Provide best practices/experience for network
operators
   • Collecting Performance Stories
   • Campus Network Infrastructure Guide
   • Pointers to relevant projects

                Comcast: Abilene Measurements & End-to-End Performance   29-Sep-2003   17
       Reference


http://e2epi.internet2.edu




               Comcast: Abilene Measurements & End-to-End Performance   29-Sep-2003   18
www.internet2.edu

				
DOCUMENT INFO