1. Networking Named Content
Paper by: V. Jacobson et al.
Presented by : Haroon Rashid
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2. Content Centric Networking
 No NAT traversal.
 Address space exhaustion.
 Average latency and total bandwidth is minimized.
 Networking in mobile scenarios is easy.
Content Centric Networking (CCN) removes the concept of
host identities (machine address) required for communication
and considers only named data packets. Some of its benefits:
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3. Different Paradigms
IP Networking CCN Networking
Source: Lecture Notes on Internet 3

4. IP vs. CCN Network stack
IP Network Stack CCN Network Stack
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5. CCN Packet Types
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6. Forwarding Engine
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7. Naming/Hierarchical Addressing
Query Traversal
Address Structure
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8. Routing
 CCN Uses name prefixes instead of IP prefixes.
 Name prefixes are broadcasted via routing protocols.
 Conventional routing protocols like IS-IS and OSPF are
used in CCN by utilizing a general TLV(type label value)
scheme.
 Each node builds its FIB on receiving prefix.
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9. Routing
Steps
1. Local map gets build up by
hello packets – adjacency
matrix.
2. Information of data
availability at a node gets
disseminated via Prefix
announcements (IGP-LSA).
 Prefix based longest
match lookups.
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10. • CCN supports multicasting when more than one
announcer of data is found at a particular node while
as IP supports only uni-casting in such a case.
• For inter domain routing, BGP supports equivalent
of IGP TLV mechanism.
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11. Security
• Security is build within data itself rather than
securing data channel.
• Digital signatures are used for authentication.
• Cryptographic encryption is used for private data
protection.
• Signature in each data packet is over the packet
name, the content, and on signed-info.
• Decryption keys are distributed along content as a
CCN data blocks – no need of trusted servers.
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12. Network Security
• No tampering is possible due to digital signatures.
• Impossible to send the malicious content to a particular
machine as host identities are not revealed.
• Data-based distributed denial of service attacks not possible
as filtering of each data packet takes place at each
aggregation point towards content customer.
• For Interest flooding attack, attacker should be expert in
providing the different combinations of name components
of a prefix served by the target.
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13. • CCN’s semantically selective control also
mitigates different attacks:
• Data packets follow same path as Interest – helps
intermediary routers to have fine grained control of Interests
forwarded under a certain prefix.
• Attacked domain can ask downstream routers to throttle
number of Interest packets for a certain prefix.
• Provides tools to organizations to control their
content travel.
• Policy based routing – requiring content name and signer.
• Interests can be digitally signed to enable the policy routing
by how often and into what namespaces a particular
consumer may query.
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14. Evaluation
• More time to reach to
throughput asymptote in
CCN due to store and
forward stages.
• Un-optimized task level in
CCN vs. optimized kernel
level implementation in
TCP.
• CCN’s lower throughput due
to its encapsulation in
IP/UDP and its own headers.
• But remember CCN’s
implicit data security.
BULK DATA TRANSFER
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15. Performance in secure & insecure
scenarios
• CCN over Jumbo-UDP is twice as efficient as HTTP and
three times more efficient than HTTPS in both overhead
and packets (sent).
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16. Performance in data sharing scen.
• The performance penalty of using CCN vs. TCP is around
20% while the performance gain from sharing is integer
multiples, there is a net performance win from using CCN
even when sharing ratios / hit rates are low.
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17. Architecture Difference
DONA
• Name given to packet is a
cryptographic hash of
publisher’s key and label.
• DNS type table required for
resolution of user familiar
name to digest based.
• Flat Namespace.
• Content must be first
registered with RHs.
CCN
• Name given is not a
cryptographic digest of
anything.
• User friendly, structured,
location independent
names.
• Hierarchical Namespace.
• Content generated
dynamically in response to
queries.
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18. Concerns
• Names based on digest vs. user friendly,
structured names.
• Hierarchical namespace vs. flat namespace.
• Inter-domain routing feasibility.
• Caching level & replacement policy at the
intermediary routers.
• Does it depends on the ISP?
• Can we improve forward strategy?
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