Routing papers in ccn
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Transcript of Routing papers in ccn
INFORM: a dynamic Interest FORwarding for Information Centric Networking
By R. Chiocchetti et al.Presented by: Haroon Rashid
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INFORM design goals
i. To discover paths to temporary copies of a content item
ii. To forward requests for such content items towards the « best » interface
iii. To guarantee data delivery
iv. To limit the network overhead
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INFORM Working
A B
C
Interfaces
D
Producer
Consumer
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Evaluation – Average packet download time
• The download time decreases as the connectivity increases
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Evaluation – Average packet download time (cont'd)
• Delivery time sharply decreases as the cache size until additional storage capacity does not provide any benefits
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Take aways
Efficiency of algorithm depends upon the frequency (Popularity) of requested file. E.g., works well in YouTube, Google News etc.
Accuracy of best interface estimation depends upon Nr.
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NLSR: Named-data Link State Routing ProtocolBY: A K M Hoque et al.
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NLSR
Intra Domain routing protocol Link state Use device names for identification instead of IP
addresses Produces multiple paths to same destination with
relative associated cost(hop count)
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Approach
Each router advertizes LSA. Adjacency LSA -- set of active links at router. Prefix LSA -- name prefix registered with a router.
Each router stores LSA into LSDB.
Different LSA Types
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Route Calculation
At each router (i) through each neighbor (v) for a particular destination (d) Dijkstra’s algorithm is run. This gives a list of next hop ranked neighbors for a particular destination (d).
This fine grained information is inserted into FIB.
i
v
v
V1
V2
V3
d
v
v
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LSDB Synchronization
Router A Router B
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Eval: Convergence with & without Multipath support
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A Two-layer Intra-domain Routing Scheme for Named Data NetworkingBy: H. Dai et al.
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Deals with:
Intra-domain routing. Two layer routing protocol:
Lower layer: Topology Maintaining (TM) Layer Upper layer: Prefix Announcing (PA) Layer
Active Publishing/Passive Serving Trade-offs between active publishing and passive
serving
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TM Layer: Maintains full topology of the entire network i.e.,
connectivity and bandwidth. Provides shortest paths information as a service to
upper layer (PA). PA Layer:
Publishes content (prefix) that a router wants to serve Routers build their FIB on receiving prefixes.
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PA Layer
Com/google/maps/USA/CA/Anaheim
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Scalability
Large Network -> More routers ->More Publishing -> FIB explosion
Active publishing vs. Passive Serving Active publishing -> FIB explosion Passive Serving -> Traffic explosion
Solution lies in content popularity More Popular - Publish otherwise serve passively
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Data popularity based approach
Publish the popular content and serve passively unpopular content.
Popularity property – access frequency Access frequency should be greater than particular
threshold. Large threshold -> massive interest flooding Small threshold -> large sized FIB
FIB suppression: Each announcement have threshold value (a) Each router have its own threshold value (p)
Depends upon memory size and other factors. If a>p, insert into FIB and relay otherwise relay only.
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Cost Ratio Cost Ratio=Ppassive/Cactive
Evaluation: Cost Ratio
Where, In Ppassive: N – is consumer Node1 is producer dN – degree of node In Cactive : E,L - # of edges
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Eval: Active vs. Passive mode comp.
• It is non-trivial to calculate the threshold value• As P increase less content is published and FIB size decreases.
Whereas more traffic gets generated for the content as served passively
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Adaptive Forwarding In Named Data Networking By: C Yi et al.
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Goal: Retrieve data through best performing path Detect packet delivery problems and their recovery.
Problem Identified in current architecture Interest not satisfied by a node -> No feedback to the
requesting node -> only timer helps. Within duration of timer lots of interests get piled up.
AB
E
CD
SInterest Interest
Inte
rest
Interest
Solution:Interest NACK packet
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Interest NACK: Carries same name as Interest packet. Carries an error code explaining NACK generation
Congestion , No path etc.
Interface Ranking Based on Routing preference (neighbor biased) Observed forwarding performance (past history) Forwarding policy set by operators