Transcript TRIAD and Internet Addressing at the Edge Prof. David Cheriton

TRIAD and
Internet Addressing at the
Edge
Prof. David Cheriton
Computer Science Department
Stanford University
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What is TRIAD?

NAT-based Internet Architecture
» end-to-end semantics
» highly scalable
» compatible with IPv4
» extended directory services
DARPA-sponsored project, Aug. 1999
 http://www-dsg.stanford.edu/triad.html

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TRIAD vs current NAT

Name-based E2E identification
» DNS names, not end-to-end addresses
» Reliable, secure router-integrated directories

End-to-end semantics
» name-based pseudo-header for checksum

WRAP shim protocol for extended address
» Intra-realm: normal IPv4 forwarding
» Inter-realm: Translation and relaying
Fixes problems with NAT, fixes the Internet
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Similar to Current NAT
Realms
Realm 1
src
Realm 2
Internet
RA1
RA2
dst2
dst1
Intra-realm: IPv4 operation
 Relay Agent (RA) - extended NAT device

» local name service, private addrs alloc.
Addressing at the edge: private addrs and
locally-managed global names
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Relay Agent Functionality
NAT between local private addresses and
global Internet addresses
 Local addr. alloc. and auto-config, DHCP
 Split DNS:

» internal access to global names
» external access to local names
Firewall protection from Internet
 Monitoring and shaping for ISP SLA
 Multi-home the edge net for availability
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Benefits
Edge: Autonomy, convenience, protection,
control, low-cost IPv4 devices
 ISP: charge per “global” address and peruser specified name suffix

» customer takes responsibility for protection
Apps: app.-independent and soft-state
 Internet: No need to make the transition to
IPv6 routers, protocols, net. man. etc.
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http://wwwdsg.stanford.edu/triad.html

Having a “border” to the edge is established
» NAT, firewall, edge router
» the flat and open Internet is long gone

Leverage the border device to:
» insulate the core from edge naming and
addressing requirements
» support edge autonomy and configuration

TRIAD to regain transparency and
application-independence thru the border.
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