Transcript Rethink the design of the Internet

Rethink the design of the
Internet
CSCI 780, Fall 2005
E2E argument is great
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Complexity of core network is reduced,
easy to upgrade
Generality of network makes new
applications easy to add
Increases applications’ reliability
Moving away from E2E
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Operation in an untrustworthy world
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More demanding applications
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Enhanced service is limited to one ISP
Third-party involvement
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Streaming audio and video
ISP service differentiation
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Enforce ‘good” behavior
Interpose between the two ends
Less sophisticated users
Technical responses
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Different forms of E2E argument
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Modify the end-host
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Core (in the network)
Edge (on or attached to the network)
Sometimes it does not work
More functions to the network
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Firewall, traffic filter
NAT box
Packet labels (marking)
Trends at application layer
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Insert intermediary into data path due
to performance or security reasons
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Anonymizing senders
Content (layer-7) filtering
Content caches (Web proxy, CDN)
Application requirements become more
complex
Current Internet is changing
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Rise of new players
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Commercial ISPs (Internet Service
Providers)
Tussle between ISPs
Erosion of trust
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Security issues (global communication with
local trust)
Two tenets valued but
disobeyed
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Each Internet entity has a global
identifier that allows others to reach it
Network elements should not violate
network layering
Middle-box violates tenets
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Network address translator (NAT)
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Pros:
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expands the IPv4 address space;
address isolation
Cons:
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p2p fails to work;
layer violation;
complicate new protocol or application design;
Private IP address
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IANA (Internet Assigned Numbers Authority)
has reserved three blocks of the IP address
space for private internets:
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10.0.0.0 - 10.255.255.255 (10/8 prefix)
172.16.0.0 - 172.31.255.255 (172.16/12 prefix)
192.168.0.0 - 192.168.255.255 (192.168/16 prefix)
First is a single class A network number, second block is a set of
16 contiguous class B network numbers, third block is a set of
256 contiguous class C network numbers.
Delegation-oriented
architecture (DOA)
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Goal: retain the functionality of middlebox, but eliminate their dangerous sideeffect
Approach:
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Provide a globally unique identifier in a flat
namespace (160-bit EIDs)
Explicit delegation