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Virginia Tech Campus Network Overview

Virginia Tech Campus Network Overview. Internet2 Campus Focused Workshop On Advanced Networks Clark Gaylord Virginia Tech cgaylord@cns.vt.edu http://rdweb.cns.vt.edu/ 30 May 2001. Basic Services. Basic Ethernet portal service (~25,000 ports) Switched 10Base-T (10 Mbit/s)

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Virginia Tech Campus Network Overview

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  1. Virginia Tech Campus Network Overview Internet2 Campus Focused Workshop On Advanced Networks Clark Gaylord Virginia Tech cgaylord@cns.vt.edu http://rdweb.cns.vt.edu/ 30 May 2001

  2. Basic Services • Basic Ethernet portal service (~25,000 ports) • Switched 10Base-T (10 Mbit/s) • Some switched 100Base-TX (100 Mbit/s) • Dial-in modem pool with ~1,200 56k modems • Wireless LAN (currently in pilot phase, beginning second round deployment) • ATM portal service (25 or 155 Mbps), mostly for specialized applications (e.g. distance learning programs) • Local network access point provides campus backbone access to local ISPs. Ethernet in apartment complexes • Telephone (~13,000 phones) and cable television (~5,000 connections) Gaylord: Virginia Tech Campus Overview

  3. Some Network Management Tools • Largely home-grown • ARP/Forwarding table/Cable plant databases (HC++ ™) • Device status reports • TACACS+ database query tool • nemisys - Network Engineering Management Information SYStem ™ • Various ad hoc tools • People • Commercial • Smarts InCharge • Concord Network Health • InterMapper, What’s Up “inventory” tools (“Your switch is still alive.”) • Freeware, etc • Usual suspects: MRTG, Big Brother, Netsaint Gaylord: Virginia Tech Campus Overview

  4. ARP/MAC mappings 1 Gaylord: Virginia Tech Campus Overview

  5. ARP/MAC mappings 2 Gaylord: Virginia Tech Campus Overview

  6. Roll your own Gaylord: Virginia Tech Campus Overview

  7. End-to-End Management • Largely ad hoc, informal measurements • ttcp, netperf, treno, Ganymede • nlanr AMP project • How to you obtain measurements from the far end? • Usual SNMP tools cannot/do not address burstiness • Configuration management/production quality Gaylord: Virginia Tech Campus Overview

  8. ISM Gaylord: Virginia Tech Campus Overview

  9. AMP Gaylord: Virginia Tech Campus Overview

  10. Switched 10 Mbps to the desktop. Switched 100 Mbps where desired. Switched 100 Mbps building backbone. N x 100 Mbps scalable building feed. Simple model ISL virtual LAN capability Standard Building Network Catalyst 1900/1924 Catalyst 1900/1924 Catalyst 1900/1924 Catalyst 1900/1924 100Base-FX downlinks Catalyst 1900/1924 10Base-T to wall portal Cisco Catalyst 6500 n x 100Base-FX Cisco Catalyst 5000 Core Gaylord: Virginia Tech Campus Overview

  11. 10/100 available to the desktop Scalable Gigabit Ethernet building backbone and building feed 802.1Q/ISL virtual LAN capability 802.1p packet prioritization capability 802.11b Wireless LAN Deployed in Torgersen Hall Wireless LAN Access point Advanced Building Network Catalyst 3500 Catalyst 3500 1000Base-TX inter-switch links Catalyst 3500 Catalyst 3500 Catalyst 3500 Catalyst 3500 1000Base-SX downlinks Catalyst 3500 Catalyst 3500 10/100Base-TX to wall portal Cisco Catalyst 6500 n x 1000Base-LX Cisco Catalyst 6500 Core Gaylord: Virginia Tech Campus Overview

  12. Current/pilot: Torgersen (ACITC) Information Systems Summer 2001: Library (partial) Student Centers (partial) Randolph (Engineering) Pamplin (Business) 2001-2002: Veterinary Medicine Seitz (Agriculture) McBryde (Math, CS) Wireless LAN Deployment Plan (2001-2002) Gaylord: Virginia Tech Campus Overview

  13. Wireless LAN Deployment • Two-three year deployment schedule • Instructional space • Student centers • Other space as needed • Facilities to support portable computing • Based on 802.11b • Economics of 802.11a dubious • Keep it “standards” based • Large perimeter • WEP/ESSID not supportable, negligible benefit • 802.1X/EAP • a definite maybe • Airspace internal policy • Custom antenna design? Gaylord: Virginia Tech Campus Overview

  14. VT Gigabit Backbone 2 x 1000Base-LX 1 x 1000Base-LX BUR Catalyst 6500 1 x 1000Base-SX 1 x 100Base-FX/TX HIL Catalyst 6500 ATM OC3c Future POS/DPT/ATM OC12c or 1000Base-ZX SHA Catalyst 6500 ISB Catalyst 6500 OWE Catalyst 6500 ISB Catalyst 6000 Modem Pool ISB Cisco 7500 CAS Catalyst 6500 ISB Cisco 7500 MSAP DSL Internet VT ATM Backbone CAS Cisco 7500 T1/FR N.W.V Internet2 LMDS Gaylord: Virginia Tech Campus Overview

  15. ATM Architecture • ATM provides key benefits, not yet feasible or cost-effective using other technologies • Integrated, multi-service WAN access • Voice transport (toll-bypass) • Videoconferencing (distance learning) • IP data transport • Layer 2 virtual private networks with explicit resource provisioning; vital to network layer research. • Also provides last-resort backup for the gigabit backbone. • When all else fails, we haul it over ATM. Gaylord: Virginia Tech Campus Overview

  16. VT ATM Backbone ATM OC3c multi-mode BUR ASX-200BX ATM OC3c single-mode 1000Base-SX HIL ASX-200BX SHA ASX-200WG OWE ASX-200WG ISB ASX-1000 CAS ASX-200BX ISB Cisco 7507 ISB Cisco 7507 VT Gigabit Backbone N.W.V CAS Cisco 7507 Internet Internet2 Gaylord: Virginia Tech Campus Overview

  17. Net.Work.Virginia • Provides ATM services throughout Virginia to K-12 schools, institutions of higher education, and state agencies • Low cost access with level pricing statewide • OC3c (155 Mbit/s), ~ $134,000/annum • DS3 (45 Mbit/s), ~$53,000/annum • DS1 (1.5 Mbit/s), ~$12,000/annum • Provides Internet access services, as well as supporting a wealth of ATM-based services (intranet, videoconferencing, PSTN toll bypass, etc) • Provides access to research backbones (e.g. Abilene) • Currently 595 sites Gaylord: Virginia Tech Campus Overview

  18. Regional LEC ATM Regional LEC ATM Sprint Public ATM ESnet Abilene (Internet2) Net.Work.Virginia OC-12c POS OC-12c POS OC-12c ATM WTN ASX-1000 N x OC-3c/DS-3 ATM SprintLink (Internet) WTNGSR12016 WTNGSR12016 ROAGSR12016 RICGSR12016 Regional LEC ATM Regional LEC ATM ROA ASX-1000 RIC ASX-1000 Regional LEC ATM Regional LEC ATM Regional LEC ATM Regional LEC ATM Gaylord: Virginia Tech Campus Overview

  19. Quality of Service • Traffic Classification • Congestion Avoidance • Policing • WRED • Congestion Management • CBWFQ • Shaping/Conditioning Gaylord: Virginia Tech Campus Overview

  20. Traffic Classification • DSCP/IP Precedence marking • Classify different classes of “Best Effort” to protect each from each other • Classes can be based on users or applications • Use netflow to determine major applications • Use business rules to determine major user bases Gaylord: Virginia Tech Campus Overview

  21. Traffic Classification • Only bits 0-2 are used (DiffServLite?) • Control Plane (DSCP=56(?) set by routers) • IP Telephony (DSCP=40(?) set by end-station) • On-campus any-to-any (DSCP=24) [Following are destined off-campus] • Non-residential (aaanet) TCP (DSCP=16) • Residential (resnet) TCP (DSCP=8) • Other residential and non-residential (notTCP) (DSCP=0) • Should these be xxxx11? • Except for IP Telephony and control plane, classification is done at entry to core (DSCP is only trusted in one edge VLAN, viz. telephony) • No use of 802.1p (outside of telephony LAN) Gaylord: Virginia Tech Campus Overview

  22. Traffic Shaping • Outgoing only (ATM OC-3 … nominally 100Mbps) • aaanet 40Mbps • resnet 40Mbps • notTCP 10Mbps • CBWFQ • No priority queuing (at this time) • No shaping for on-campus traffic Gaylord: Virginia Tech Campus Overview

  23. Traffic Policing • On-campus • No policing • All best-effort • Lots of excess capacity • Incoming to campus • Same as on-campus • Outbound • Police resnet to 60Mbps (nominal 60% of Internet pipe) at entry to border area • Formerly specifically policed “application of special interest” Gaylord: Virginia Tech Campus Overview

  24. Path of a packet Catalyst 1900/1924 Catalyst 1900/1924 Catalyst 1900/1924 Catalyst 1900/1924 100Base-FX downlinks Catalyst 1900/1924 DSCP marking happens here Cisco Catalyst 6500 n x 100Base-FX Cisco Catalyst 5000 Core Gaylord: Virginia Tech Campus Overview

  25. Modem Pool VT ATM Backbone Path of a packet BUR Catalyst 6500 From building network DSCP marking happens here HIL Catalyst 6500 SHA Catalyst 6500 ISB Catalyst 6500 OWE Catalyst 6500 ISB Catalyst 6000 ISB Cisco 7500 CAS Catalyst 6500 MSAP Policing happens here ISB Cisco 7500 DSL Internet N.W.V CAS Cisco 7500 T1/FR Internet2 LMDS Conditioning happens here Gaylord: Virginia Tech Campus Overview

  26. What we have learned • Outbound congestion creates poor inbound TCP performance • Conditioning alone does not work well when offered load is high • Leave room for bursts (set sum of committed traffic to 90% of link?) • Policing alone works for isolated traffic classes • Doing anything is better than doing nothing - even for voice • Divide and conquer Gaylord: Virginia Tech Campus Overview

  27. Futures • Priority queuing for voice • Traffic classes for distance learning (DLoIP ™), Research Computing, et al. • Per-user classification and user-class policing • Netflow data gathering and traffic classification • Remote monitoring of end-to-end performance • How do we measure bursts? Gaylord: Virginia Tech Campus Overview

  28. For More Information • http://rdweb.cns.vt.edu/ • http://www.networkvirginia.net/ Gaylord: Virginia Tech Campus Overview

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