Internet Exchange Point Design

95 Pages·2015·0.8 MB·English

by  Philip Smith

Internet Exchange Point
Design
ISP/IXP Workshops
1
Last updated 23rd March 2015
IXP Design
Background
p 
Why set up an IXP?
p 
Layer 2 Exchange Point
p 
Design Considerations
p 
Route Collectors & Servers
p 
What can go wrong?
p 
2
A bit of history
Where did the IX concept come
from?
3
A Bit of History…
NSFnet – one major backbone
p 
US “National Science Foundation” funded
n 
Connected academic & research institutions
n 
Also connected “private company” networks, with
n 
acceptable use policy
AUP: No commercial activity
p 
Three Network Access Points (NAPs): Chicago, New
n 
York, San Francisco
Private companies needed to interconnect their
p 
networks
Requirement to send “commercial traffic”
n 
Could not cross NSFnet
n 
Resulted in the early “commercial Internet Exchanges”
n 
4
More History…
Early Internet Exchanges created in early 90s
p 
CIX-West – west coast USA
n 
MAE-East – east coast USA
n 
D-GIX – Stockholm
n 
End of the NSFnet in 1995:
p 
Meant move towards commercial Internet
n 
Private companies selling their bandwidth
n 
ANS (operator of the late NSFnet) had to join IXes
n 
Routing Arbiter project helped with coordination
p 
of routing exchange between providers
Traffic from ISP A needs to get to ISP B
n 
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More History still…
The NAPs established late in NSFnet life were
p 
some of the original “exchange points”
NAP operators supported commercial activities as well
n 
(Sprint: NY, PacBell: SF, Ameritech: Chicago, MFS:
n 
Vienna/VA)
The NAPs replaced by IXPs:
p 
NAPs didn’t succeed (operated by ISPs), replaced by
n 
more neutral IXPs
E.g. Virginia NAP replaced by MAE-East (by MFS)
n 
Mid 90s saw rapid Internet growth, with major
p 
providers connecting…
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Even more History
D-GIX formed in Stockholm in 1992
p 
Three major ISPs interconnected
n 
Latency reduction, performance gains
n 
Local traffic stays local
n 
LINX formed in London in 1994
p 
Five UK operators interconnected
n 
Latency reduction, performance gains
n 
Local traffic stays local
n 
HKIX formed in Hong Kong in 1995
p 
Vibrant Internet community, many small operators
n 
Latency, performance, and local traffic benefits
n 
Also AMS-IX in Amsterdam in 1994
p 
Same reasons as others 7
n
Internet Exchange Point
What:
p 
A neutral location where network operators freely
n 
interconnect their networks to exchange traffic
What is the physical IX:
p 
An ethernet switch in a neutral location
n 
How does it work:
p 
IX Operator provides the switch and rack space
n 
Network Operators bring routers, and interconnect them
n 
via the IX fabric
Very simple concept – any place where providers
p 
meet to exchange traffic
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Internet Exchange Point
Layer 2 exchange point
p 
Ethernet (100Gbps/10Gbps/1Gbps/100Mbps)
n 
Older technologies used in the past included
n 
ATM, Frame Relay, SRP, FDDI and SMDS
Layer 3 exchange point
p 
Has historical status now
n 
Router based
n 
Best known example was CIX-West
p 
Router very quickly overwhelmed by the rapid growth
p 
of the Internet
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Why an Internet
Exchange Point?
Saving money, improving QoS,
Generating a local Internet
economy
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