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04/21/23 CS622 - MIRO Presentation 1
Wen Xu and Jennifer RexfordDepartment of Computer Science
Princeton University
Chuck ShortCS622
Dr. C. Edward Chow
Autonomous System (AS) Border Gateway Protocol (BGP) Internet Service Provider (ISP)
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Single route advertisement is not flexible enough
BGP is sufficient for most traffic Control over path properties rather than
complete path is desirable Intermediate router may be willing direct
traffic along another path Current methods for influencing path
choices are limited
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BGP Single best path selection
Source Routing End to end path selection
Overlay Networks Virtual network topology
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Extension of BGP AS-Level path selection Negotiation for alternate routes Policy driven export of alternate routes Tunnels to direct traffic on alternate
routes
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Intra-AS Architecture AS may consist of many internal routers and
paths Data Plane Packet Encapsulation
IP over IP encapsulation Control Plane Tunnel Management
Creation and destruction of tunnels based upon negotiation
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• Simulated operating environment• Infer AS relationships• Assume each AS selects and exports routes
based on business relationships• Each AS treated as one node• GAO Algorithm
– L. Gao, “On inferring Autonomous System relationships in the Internet,” IEEE/ACM Trans. Networking, vol. 9, no. 6, pp. 733–745, 2001.
• Data (October 2000, 2003, 2005)– www.routeviews.org
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Strict Policy Responding AS announces routes with same
local preference as the original default route Respect Export Policy
Responding AS announces alternate routes using an export policy
Most Flexible Policy Responding AS announces all possible routes
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1) 1-hop set AS negotiates with each immediate neighbor
2) Path set AS negotiates with any AS along BGP path
300 million (source,destination) pairs evaluated
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Avoid for security or performance reasons
Calculate triple for every (Source, Destination, AS to avoid)
Don’t avoid immediate neighbors
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Assumptions Each source generates equal traffic
Total traffic estimated by number of sources using link
All traffic sent through an intermediate AS always transits through that AS Total traffic a single AS can move if switched to a
different route
Power node concept Node lies on destination path for many
sources
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10,383 multi-homed AS studied Around 90% can move 10% of traffic 50% can move
40% of traffic under flexible policy 25% of traffic under strict policy
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90% of Power Nodes had 200+ neighbors Most likely Tier 1 AS
Immediate neighbors only constitute 9% of Power Nodes
68% of Power Nodes are 2 hops away
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Need negotiation rules Establish and manages negotiation process
Need route selection rules Filter and rank available alternatives
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Potential for oscillation Solution:
If upstream AS does not advertise the tunnel MIRO is guaranteed to converge whenever BGP converges
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MIRO is backward compatible with BGP MIRO can provide the flexibility to
negotiate alternate routes as needed MIRO can provide transit AS more control
over traffic across their network MIRO is comparable to Source Routing at
avoiding an intermediate AS Most alternate route possibilities are
provided by the most connected nodes (ISP’s)
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Build prototype Explore security via AS trust relationships Devise centralized load balancing scheme
to prevent oscillation Explore the incorporation of price,
performance and load information into the route selection process
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Border Gateway Protocol (BGP) http://www.rfc-editor.org/rfc/rfc4271.txt
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