Transcript FIND experimental requirements

FIND experimental
requirements
David D. Clark
FIND
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Future Internet Design (FIND) is an NSF
program (now folded in to NetSE) to
envision the Internet of 15 years from now.
FIND was one of the early drivers for the
development of GENI.
FIND research spans the layers from
technology through classic Internet
architecture to application design.
The original Science Plan
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As part of the original work on GENI, we
prepared a Science Plan (also called the
Research Plan), which listed various
requirements.
Those requirements have not changed.
The GENI plan, as then proposed, (and
now?) did not fully meet those
requirements.
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Suggests a need to revisit some assumptions
and design approaches.
General requirements
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A real, distributed network.
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Reach to the edge.
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Allow experimental edge equipment direct connection
to the GENI-based experiments.
Access to real users.
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Not a bunch of routers in a rack.
As wide a reach as possible.
Creates a tension with the desire for realistic lower
layer technology, e.g. optical layer.
Long-running experiments.
Background commentary
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There are a wide range of experiments (with a wide
range of requirements) that might be posed for GENI.
It is not realistic to imagine that we can build a single
fully general facility that can support all of these
experiments at reasonable cost.
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The MREFC process distorted the translation of
requirements into facilities
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Implies a need to be creative, make clever choices. Make some
compromises.
E.g. a single unified facility.
All of these assumptions should be reconsidered.
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One or many? Is GENI one thing?
A better set of outcomes?
The excitement is at the edge
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While (some of us) want to mess with the core
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Security, management, etc.
The real action is at the edge.
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New devices (mobile, embedded)
New networks (wireless of all sorts)
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Not all parts of the network will look like ethernet!
Cars and other mobile networks.
To emulate the future, need all this in the
experiment.
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Not so clear how to virtualize. Does this matter?
Remember the goal of reaching real users.
The excitement is at higher layers
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Design patterns for applications.
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New support mechanisms
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Highly distributed, clouds, etc.
Identity frameworks, location frameworks, etc.
Important to ask: to what extent can we
explore these on the existing Internet?
New protocol stacks
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Researchers want to try new protocols at the
network, transport (and higher) layers.
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New means of authentication.
New mechanisms to deal with soft state in the
network.
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Implies the need to replace the protocol stack in
the end node.
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Facilitating this should be part of GENI effort.
Mobile devices, not just PCs.
Remember, we want real users.
A real experimental tension here…
Lower level research?
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Two sorts of reasons.
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We need to do a better job supporting apps.
Security, availability, management, economics, etc.
 (It is not the data plane, except indirectly…)
 What happens there will influence the design of
applications.
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The research is not independent.
We don’t have the lower levels right.
Management, operations, etc.
 Some of this is perhaps more independent.
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Packets
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We want to try out packet formats that are not
IPv4 and IPv6.
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Congestion and its control.
Novel addressing modes
New mechanisms for security.
New concepts in network management.
New schemes for tracking payment.
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This capability must reach all parts of the
experiment.
New functions “in” or “on” the net
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Not all boxes that are topologically “in the network” are
routers.
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Security enforcement devices.
Encryption devices.
Packet inspection devices.
Application support devices.
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Implies different node requirements.
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More storage, processing, etc. Very high performance.
Network devices today are highly purpose-tuned.
How can we provide generality for a range of experiments with
different topological requirements?
Processing nodes should be in the net, not just at the edges.
Emulating a real network
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The core of a big ISP today does not forward
packets, but is built of flows that carry
aggregates of packets.
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Optical lambdas, MPLS circuits, etc.
Not all parts of the network will look like ethernet!
Cost and complexity is a major driver in real
nets.
A future architecture should do a better job of
linking the management of these layers.
How should these capabilities be made
available to experimenters? Should this be a
GENI goal?
Optics in the core
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The original proposal for the GENI platform had
rather sophisticated optical components in the
core.
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This had major cost implications.
This had major “virtualization” implications.
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E.g. ROADMs.
How do you virtualize a ROADM, since it is not a
packet device?
Not well done in original proposal.
The goal was to at least emulate how real
networks look today.
One alternative
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Let the folks who want to play with real
optics build their own environment.
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Smaller scale?
Build the large scale testbed out of
packets (IP, ethernet: does it matter?) and
tunnel our “new packets” inside them.
Is this a better idea? (It has limitations that
should be recognized, as well as benefits.)
Picking compromises
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If we fold optics in…
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More realistic (but for what class of experiments?)
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QoS, non-packet end-to-end services.
Intrinsic availability, security, management, etc.
Cross-layer protocol designs.
If we use packets and tunnel…
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Much easier to achieve scale and reach real users.
Lower layer “technology complexity” will have to be
simulated. Is this an issue?
Another way of saying this
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The independence of the parts of the Internet
(e.g. apps from link technology) is as a result of
the “hourglass” design, the end-to-end design,
etc.
Assuming that experiments can tunnel over
packets risks baking in today’s hour-glass
architecture in tomorrow’s experiments.
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My opinion: the risk of guiding research toward a
presumption of the hourglass has to be mitigated in
some way.
Management
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As the previous slide tried to emphasize, a
lot of future Internet research is about
management, not the data plane.
So GENI is not just virtualized data
planes, but virtualized network
management schemes.
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Fault diagnosis.
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Virtualization messes this up.
Set up and tear down of circuits.
Want to mimic real operators, not just users.
A general challenge for GENI
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Many of the proposed ideas for a future Internet
stress management, security, etc.
It may be less clear how to virtualize the
experimental infrastructure to allow these to be
demonstrated than to virtualize the data plane.
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For example, to demonstrate improved availability,
the GENI platform would ideally mimic the baseline
failure modes of the eventual technology.
What is the best set of compromises?
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Again: one GENI facility or many?
Scale and speed
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Some experiments stress scale
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100’s of routers, 100’s of fixed end-nodes,
N00’s of mobile devices, and rich connectivity.
Others mention “thousands of interconnected
devices”.
Speed was not an issue for this experiment.
These are miniscule experiments!
Real scale
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10K-100K AS regions.
Routers with 500 10 Gb ports.
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100 striped lambdas…
Millions of multi-homed end-nodes.
Highly heterogeneous environment.
How are we going to try (and validate)
ideas at these scales?
Some specific requirements
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Rich connectivity (to experiment with novel
routing.)
Need for multiple regions (emulate different
operators).
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Heavy-duty isolation among slices.
Detecting physical location.
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High bandwidth paths between slices?
All devices should be able to do this.
Universal crypto capability.
Allow experiments in virtualized architectures.
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Recursive virtualization?
Instrumentation
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In some respects, a confused discussion.
Clearly, we need to gather data on how
experiments are going.
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But is this done in the infrastructure, or in the
slice?
A future Internet must include native
capabilities for instrumentation.
Is “data” something generic that is
shared? Wishful thinking?
Non-requirements
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Satellite
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Not a sufficiently distinct challenge.
Residential access networks
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Again, a challenge, but not sufficiently
distinctive.
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If have wireless nets and high-bandwidth links to
end-nodes, good enough.
The experimental landscape
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How many experiment?
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PlanetLab has demonstrated that there can
be 1000’s of experiments.
But how many folks want to try out a new
Internet?
Perhaps we need different sorts of tools for
experimental deployment at different “layers”.
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Again, one GENI or many?