OSPFN A K M Mahmudul Hoque, Gus Sanders, Lan Wang (University of Memphis), Cheng Yi, Yifeng Li, Beichuan Zhang (University of Arizona)

1. Routing on NDN Testbed
A K M Mahmudul Hoque, Gus Sanders, Lan Wang !
University of Memphis!
!
Cheng Yi, Yifeng Li, Beichuan Zhang !
The University of Arizona!
9/13/2012 CCNx Conference 0

2. Routing Protocol
! Goal: develop a routing protocol for NDN
testbed.!
! What we did: extend OSPF to route on names.!
" Version 0.1: add name prefixes.!
" Version 0.2: configured multiple forwarding faces.!
! What we’re doing: a link-state routing protocol
based on named data.!
9/13/2012 CCNx Conference 1

3. OSPF Extension
! OSPF!
" Nodes advertise their IP prefixes and local links, i.e.,
Link State Advertisement (LSA).!
" Each node has complete topology and compute shortest
paths.!
! OSPFN!
" Nodes also advertise name prefixes in opaque LSAs.!
" Leverage OSPF to get shortest paths to each node and
name prefix.!
" Install name-prefix FIB to CCNx.!
" Developed based on Quagga source code.!
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4. Testbed Deployment
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! OSPFN has been deployed for almost a year. It now runs on 17 sites.!
! Latest topology at http://netlab.cs.memphis.edu/script/htm/topology.htm!
!
3

5. Network monitoring
! Network status is monitored periodically by scripts.!
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6. Problems
! Need GRE tunnels!
" The source of many problems in deployment.!
! Need manage IPs!
" To make sure no conflict in tunnel addresses.!
! Multipath forwarding limited by OSPF.!
! No security for routing messages.!
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7. Named-Data Link State Routing
! Name each router and link, rather than relying
on their IPs for identification.!
" No need to manage extra IP addresses.!
! Disseminate routing information as interest/
data, rather than OSPF messages.!
" No need for extra tunnels.!
" Routing data is signed.!
" Compute multiple forwarding options.!
9/13/2012 CCNx Conference 6

8. Routing exchanges
! OSPF has three types of exchanges!
" HELLO between neighbors!
" Database synchronization between neighbors!
" Flooding LSAs throughout the network!
! Named-Data routing only needs one!
" Sync up LSA database with neighbors!
" Router A sends to router B an interest summarizing
A’s LSDB. B finds out the difference and then sends
interests to A to request missing info.!
9/13/2012 CCNx Conference 7

9. Routing and Forwarding Strategy
! Forwarding strategy handles short-term churns!
" Detect packet delivery problems and try (multiple)
alternative paths.!
" Effective in dealing with link failures, prefix hijacks,
and congestions in simulations.!
! Reduce routing to a content distribution
problem!
" Sync up topology between neighbor routers.!
" Convergence time is no longer critical to packet
delivery.!
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10. Status
! The new protocol is being actively developed.!
! Plan to start deployment in 1-2 months.!
! Source code !
" https://github.com/NDN-Routing!
! CCNd status monitoring: !
" http://www.cs.arizona.edu/people/yifengl/tbs.html!
! OSPFN status monitoring: !
" http://netlab.cs.memphis.edu/cgi-bin/NDNtestbed-ospfstatus!
9/13/2012 CCNx Conference 9