Torsten Braun presented on using content-centric networking (CCN) in opportunistic and mobile networks. CCN is well-suited for these environments as it does not require neighbor discovery and can take advantage of wireless broadcast. However, short encounters require efficient transfer methods like overhearing, pipelining, and resume operations to handle disruptions. CCN also supports receiver mobility but source mobility presents challenges. The EU FP7 mobile cloud networking project is investigating using CCN for caching mobile user cloud data.

1. Alcatel-Lucent Bell Labs Holmdel
Content-Centric Networking in
Opportunistic and Mobile Networks
Torsten Braun, Universität Bern, Switzerland
braun@iam.unibe.ch, cds.unibe.ch
contributions from Carlos Anastasiades, Elham Cheriki,
Tobias Schmid, Vasilios Siris, Alexander Striffeler, Jürg Weber

2. Overview
> Introduction
— Current Research projects
— Content-Centric Networking (CCN)
— Service-Centric Networking (SCN)
> CCN and Opportunistic Networks
— Overhearing
— Resume Operation
— Pipelining
— Multicast
— Delegation Service
> CCN and Network Coding
> CCN and Mobility
> EU FP7 Integrated Project: mobile-cloud-networking.eu
— Mobile Cloud Network (MCN) Architecture
— Micro / Macro Data Centres and Virtual Mobile Networks
— Follow-Me Cloud
> Conclusions
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3. CDS Research Projects
Regensdorf, November 30, 2011
Torsten Braun: Computer Networks and Distributed Systems Research
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Wireless
Networks
Cloud
Computing
Content-Centric
Networks
Service-Centric
Networking
Mobile Cloud Networking
Enhanced Mobile Communication
with Content-Centric Networks
Integral Indoor 3D Guidance and
Access-Control System (In3DGuide)
Swiss Academic
Compute Cloud

4. Content-Centric Networking (CCN)
> Messages
— Interest: content name, selector
— Data: content name, signature (info), data
> Hierarchical content names
— Example: /unibe.ch/braun/lecture/os/20130521
> Related Projects
— NDN = Named Data Networking, www.named-data.net
— CCNx = Open Source Core Software Project for
Content-Centric Networking, www.ccnx.org
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5. Service-Centric Networking (SCN)
> Service-Centric Networking
— Extension of content-centric networking to support services
— Object names for both services (functions) and content (data), e.g.,
– /youtube.com/rendering
– /unibe.ch/braun/lecture/os/20130521
— Service request (response) in Interest (Data) message
> Examples Services
— Cloud computing
– find/call cloud services (computation, storage)
– deploy cloud services
– support caching of data stored in the cloud
— Web services
— Continuous multimedia retrieval and streaming services,
— Event services, e.g., exceeding sensor/stock data thresholds
— In-network services, e.g., aggregation and filtering of (sensor) data
T. Braun, V. Hilt, M. Hofmann, I. Rimac, M. Steiner, M. Varvello: Service-Centric Networking,
IEEE International Conference on Communications Workshops (ICC), pp.1-6, Kyoto, 5-9 June 2011
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6. Service-Centric Network
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Service request/response
SCN router
SCN network

7. SCN Prototype Evaluation
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user1 ccnd1
client1
user2 ccnd2
client2 ccndr
conversion
service &
repository
CCN router
ccndp
publisher
1/8
2/7
11/12
3
5
6
4
13/14
18/19
10
15
9
16
17/20
186 31 4
0
50
100
150
200
1-8 9-16 17-20
time [s]
1-8: Client 1 retrieves bit map image (36 MB)
9-16: Client 2 retrieves JPEG image (6 MB)
17-20: Client 1 retrieves JPEG image
Torsten Braun, Andreas Mauthe, Vasilios Siris:
Service-Centric Networking Extensions,
28th ACM Symposium on Applied Computing,
Coimbra, Portugal, March 18 - 22, 2013

8. CCN and Opportunistic Networks
> CCN and Opportunistic Networks seem to be a good match.
— No beaconing required to learn about neighbor nodes
— No need for neighbour lists
— Exploitation of broadcast property of wireless media:
→ single Interest to many neighbor nodes
> Reduced delay and network load due to possible caching
> Issue: Short node encounters require
— Efficient data transfer
– Overhearing broadcast transmissions
– Pipelining
— Resume operations to handle disruptions
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Encounter

9. Overhearing
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2
1
3
4Interest
Data

10. File Exchange in Opportunistic Networks
> Problems:
— File exchange might not be completed during short encounter.
— Caches do not store data persistently
> Solution:
— Partial file download and resume operation
(supported by meta data per file)
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Name of Content Object
Version of Content Object
Next Segment
File Position
Publisher’s public key digest
Expiration time

11. Resume Operation
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12. Evaluation of Resume Operation
> Scenario:
— 1 source and 1 consumer
— 1 disruption after a certain amount of exchanged data
> Evaluation of transfer time for a 5 MB file with PCEngines
ALIX wireless mesh nodes and different data message sizes
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13. Pipelining
> Pipelining to support fast file exchange
> TCP-like control of pipeline sizes
— Slow start and exponential increase of concurrent Interest messages
> MAC layer unicast:
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14. Multicast
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> Problems by MAC layer multicast
— No MAC layer ACKs / retransmissions
— Interest retransmissions

15. Energy Consumption
> Energy consumption measurements in a 3 wireless mesh node
scenario with multicast using digital multi-meter
> Energy consumption for a 5 MB file transfer
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16. Delegation Service
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17. Network Coding and CCN
> Regular case:
— 4 Interests + 4 Data
messages
> Network Coding:
— 3 Interests + 3 Data
messages
> Problem: Naming
> Proposal: Encapsulation
Alexander Striffeler:
Network Coding in mobile CCN,
Bachelor Thesis at Universität Bern
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Interest A
Interest B
Interest A B
Data A
Data B
Data A B

18. Network Coding of CCN Data Messages
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19. CCN and Mobility
> CCN inherently support receiver mobility !
> Problem: Source Mobility
— Finding a source’s location at the beginning of and when source is moving during
communication.
> Solutions (for general Information-Centric Networking approaches)
— Routing-based approaches
– (Proactive) updating of routing tables in case of moving sources
→ issues on scalability and convergence
— Indirection
– (Home) agent forwards all Content Requests to mobile source, cf. Mobile IP.
→ location-based identifiers, cf. location/identity separation.
— Resolution
– Receiver requests location-based identifier for a content name in a Content Request.
– Approach adds resolution phase and requires resolution entities in visited networks.
> Conclusions and Suggestions
— Both content names and locators might be needed to efficiently support CCN
source mobility.
— Flexible use of content names / locators, possibly using late binding
Vasilios Siris, Torsten Braun et al.: Content-Centric Networking Architectures for Moving Objects, COST Action
IC0906, STSM Report, 2012, http://cost-winemo.org/
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20. EU FP7 Integrated Project:
mobile-cloud-networking.eu
> Integration of
— Radio Access Network
— Mobile Core Network
— Data Centre (computing, storage, applications)
into (decentralized) cloud computing infrastructure (management!)
> Advantages: elasticity, costs, performance, e.g., by
exploitation of user location for service provisioning → Follow Me Cloud
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21. Mobile Cloud Network (MCN) Architecture
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22. Micro / Macro Data Centres and
Virtual Mobile Networks
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23. Follow-Me Cloud
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24. Conclusions and Outlook
> Conclusions
— CCN has benefits in wireless / opportunistic networks
— Services can be supported by CCN
— CCN supports receiver mobility, but source mobility is an issue.
> Outlook
— MCN investigates CCN for caching of mobile users’ cloud data
— SNSF project on SCN: service naming, routing, and management
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25. Thank You for Your Attention !
> braun@iam.unibe.ch
> http://cds.unibe.ch
> http://www.slideshare.net/torstenbraun
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