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TRIAD and Internet Addressing at the

EdgeProf. 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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TRIAD at the Edge:Similar to Current NAT

Realms

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

src

dst2RA1 RA2Internet

Realm 1 Realm 2

dst1

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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 per-user 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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Concluding Remarkshttp://www-dsg.stanford.edu/tr

iad.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.