End-to-End Lightpaths ...in the Smallest University of the - - PowerPoint PPT Presentation

▶
end to end lightpaths
SMART_READER_LITE
LIVE PREVIEW

End-to-End Lightpaths ...in the Smallest University of the - - PowerPoint PPT Presentation

Aug 08, 2023 275 likes •508 views

End-to-End Lightpaths ...in the Smallest University of the Netherlands Maurits van der Schee System and Network Engineering University of Amsterdam SURFnet GigaPort Contents Introduction What is the Smallest University? Analysis

slide-1
SLIDE 1

End-to-End Lightpaths

...in the Smallest University of the Netherlands Maurits van der Schee System and Network Engineering University of Amsterdam SURFnet GigaPort

slide-2
SLIDE 2

Dec 02, 2008 End-to-end lightpaths - Maurits van der Schee - University of Amsterdam 2/22

Contents

  • Introduction

– What is the Smallest University?

  • Analysis

– How is path configuring done now? – Is there a human problem?

  • Solutions

– How Policy Based Routing may help – How a generic switch configuration tool may help

  • Conclusion
slide-3
SLIDE 3

Dec 02, 2008 End-to-end lightpaths - Maurits van der Schee - University of Amsterdam 3/22

Smallest University?

  • A customer of a NREN typically is a university
  • The Smallest University of The Netherlands is

the smallest “customer” of SURFnet

  • We set up a path between two computer labs

for System & Network Engineering in Amsterdam and Oslo

  • What problems do you run into?
  • How can we create an end-to-end path?
slide-4
SLIDE 4

Dec 02, 2008 End-to-end lightpaths - Maurits van der Schee - University of Amsterdam 4/22

Ideal solution vs. reality

  • Ideally there would be an Inter Domain

Manager, Domain Manager and technology proxy for the university network, but...

  • In reality there is no domain management

software

  • VLAN's with or without QoS over dedicated

fiber/copper are used

  • There are some SNMP-based configuration

tools created by vendors, but CLI is favorite

slide-5
SLIDE 5

Dec 02, 2008 End-to-end lightpaths - Maurits van der Schee - University of Amsterdam 5/22

Typical university network

  • Not a single (administrative) domain
  • LAN – MAN – NREN - NREN – MAN - LAN
  • Centrally managed MAN between locations
  • This MAN is homogeneous (e.g. Cisco only)
  • Locally managed faculty and lab LAN's
  • LAN's are heterogeneous (mixed brands)
  • The Authentication, Authorization and

Accounting protocol for paths is email

slide-6
SLIDE 6

Dec 02, 2008 End-to-end lightpaths - Maurits van der Schee - University of Amsterdam 6/22

“got root?”: a human problem

  • Network administrators have enable passwords
  • There are a lot of domains in the university

network and a lot of network administrators

  • Network administrators want full control of the

configuration of their network devices

  • Network administrators do not see the need for

a higher complexity of their network

  • Network administration of the LAN's is done

informal, no network maps, no documentation

slide-7
SLIDE 7

Dec 02, 2008 End-to-end lightpaths - Maurits van der Schee - University of Amsterdam 7/22

Lightpaths or light paths?

  • “Stitching” network technologies together
  • Congestion free, low latency, point-to-point
  • Can be on either layer 1, 2 or 3
  • ... or no paths at all: over-provisioning
slide-8
SLIDE 8

Dec 02, 2008 End-to-end lightpaths - Maurits van der Schee - University of Amsterdam 8/22

Solutions in the campus

  • Layer 1: SDH, SONET, optical interconnects

– Not yet widely available in the campus

  • Layer 2: VLAN's and Ethernet bridge routing

– VLAN's and QoS are available – 802.1X may be set up

  • Layer 3: IP source based routing and QoS

– Policy based routing may be available

slide-9
SLIDE 9

Dec 02, 2008 End-to-end lightpaths - Maurits van der Schee - University of Amsterdam 9/22

QoS vs. over-provisioning

  • “It isn't clear to me that it is more expensive to
  • ver-provision bandwidth in a backbone than to

deploy QoS in that backbone. Some folks here seem to be asserting that it is generally cheaper to deploy QoS.” -- RJ Atkinson

  • (April 2001 on the end2end mailing list)
slide-10
SLIDE 10

Dec 02, 2008 End-to-end lightpaths - Maurits van der Schee - University of Amsterdam 10/22

Network topology

  • Arrows are VLAN's

(with enough bandwidth or QoS)

  • Blue scenario

VLAN to the desktop

  • Red scenario

Source based routing combined with VLAN's

slide-11
SLIDE 11

Dec 02, 2008 End-to-end lightpaths - Maurits van der Schee - University of Amsterdam 11/22

Policy based routing

  • Policy based routing can provide QoS
  • Source based routing can blend paths in
  • Source based routing is just policy based

routing with “source” as a policy

  • Traditional routing protocols do not configure

source based routes

  • Label switching may not be available in the

universities LAN's

  • Static source based routing can be improved
slide-12
SLIDE 12

Dec 02, 2008 End-to-end lightpaths - Maurits van der Schee - University of Amsterdam 12/22

Route Selection Algorithm

if packet.routeCacheLookupKey in routeCache : route = routeCache[ packet.routeCacheLookupKey ] else for rule in rpdb : if packet.rpdbLookupKey in rule : routeTable = rule[ lookupTable ] if packet.routeLookupKey in routeTable : route = route_table[ packet.routeLookup_key ] (Example 4.4 - http://linux-ip.net/html/routing-selection.html#id2550232)

slide-13
SLIDE 13

Dec 02, 2008 End-to-end lightpaths - Maurits van der Schee - University of Amsterdam 13/22

Simplify Source Based Routing

  • Default routing table is for all source networks
  • Different routing tables can be defined for more

specific networks

  • Representation is possible in a single table with

an extra column for source network

  • Precedence can be on source, destination

network instead of only destination network

  • Routing cache in Linux (and most routers)

already have source address in their tuple

slide-14
SLIDE 14

Dec 02, 2008 End-to-end lightpaths - Maurits van der Schee - University of Amsterdam 14/22

Source Based Routing

  • Traffic from host

192.168.1.9 for network 192.168.2.0/24 goes over the path

  • Traffic from other

hosts for network 192.168.2.0/24 takes the default route

slide-15
SLIDE 15

Dec 02, 2008 End-to-end lightpaths - Maurits van der Schee - University of Amsterdam 15/22

Single routing table

Destination Gateway Iface 192.168.1.0/24 * eth0 0.0.0.0/0 192.168.1.1 eth0 Source Destination Gateway Iface 192.168.1.9/32 192.168.2.0/24 192.168.1.2 eth0 0.0.0.0/0 192.168.1.0/24 * eth0 0.0.0.0/0 0.0.0.0/0 192.168.1.1 eth0

slide-16
SLIDE 16

Dec 02, 2008 End-to-end lightpaths - Maurits van der Schee - University of Amsterdam 16/22

Generic switch configuration tool

  • Software that runs on a server in the network
  • Requires managed switches that support

SNMP, SSH or Web protocol

  • Requires support of port-based VLAN's, trunks

and bonds; QoS may help to guarantee bandwidth

  • Different brands have different commands for

configuration, it should use an abstract configuration language

slide-17
SLIDE 17

Dec 02, 2008 End-to-end lightpaths - Maurits van der Schee - University of Amsterdam 17/22

Requirements

  • Aware of network layout
  • Can detect network changes
  • Trunk reserved / available bandwidth aware
  • Can create a graphical network map
  • Has a graphical (web) interface to configure it
  • May support bridge routers (ebtables)
  • Manual configuration should be supported
slide-18
SLIDE 18

Dec 02, 2008 End-to-end lightpaths - Maurits van der Schee - University of Amsterdam 18/22

Acceptation requirements

  • Must be able work with every brand of switch
  • No loss of control, should only propose new

configurations, with explanation, and should not execute them by default

  • It should help the network administrator to

document, map and monitor the network

  • It must respect the running configuration,

because network administrators must trust this tool

slide-19
SLIDE 19

Dec 02, 2008 End-to-end lightpaths - Maurits van der Schee - University of Amsterdam 19/22

Tasks

  • Network description and mapping (using NDL)
  • Network connection database (current state)
  • Network monitoring (detect network changes)
  • Path request database (requested paths)
  • Path request server (calculate configuration)
  • Provisioning server (effectuate configuration)
  • Inter domain controller (handling multi domain

requests)

slide-20
SLIDE 20

Dec 02, 2008 End-to-end lightpaths - Maurits van der Schee - University of Amsterdam 20/22

First version

  • The system should be build with it's (future)

tasks in mind

  • Can be released as soon as it complies to all

the acceptation requirements

  • This system is being build with Virtual Square's

VDE: Virtual Distributed Ethernet as a model and test environment (see: virtualsquare.org)

  • Next slide is a screen-shot of the web interface
  • f this system (still in production)
slide-21
SLIDE 21

Dec 02, 2008 End-to-end lightpaths - Maurits van der Schee - University of Amsterdam 21/22

slide-22
SLIDE 22

Dec 02, 2008 End-to-end lightpaths - Maurits van der Schee - University of Amsterdam 22/22

Conclusion

  • Simplifying Source Based Routing may help

administrators to set up end-to-end lightpaths

  • A generic switch configuration tool may help the

network administrator to bring the network administration to an acceptable level. This is necessary before we can start to implement automatic configuration

  • It is important to gain the trust of the network

administrator for automatic configuration to succeed