Multimedia and Mobile communications Laboratory

Publisher Mobility Support

in Content Centric Networks

Dookyoon Han, Munyoung Lee, Kideok Cho, Ted “Taekyoung” Kwon, and Yanghee Choi

(mylee@mmlab.snu.ac.kr)

Seoul National University

2014.02.11

ICOIN 2014@Phuket

Introduction (1/2)

Current Internet architecture

Host-based communication model

Designed to share resources

Considering “where to receive”

Internet traffic is already

content-oriented

Users/applications care

“what to receive”

So, host-based communication

model is outdated

2/18

Introduction (2/2)

Novel Internet architectures were proposed to solve the

cognitive mismatch

Information Centric networking (ICN)

New paradigm

Redesign the Internet in a clean-slate manner

DONA(Data-Oriented Network Architecture)

PSIRP(Publish-subscribe Internet Routing Paradigm)

NetInf(Network of Information)

CCN(Content Centric Networking)

3/18

CCN Overview

A subscriber sends Interest packet to request content and

receives Data packet for the content

Components for communication

Forwarding Information Base (FIB)

Forwarding table

Allows a list of outgoing interfaces

Pending Interest Table (PIT)

Keeps track of Interest forwarded

Content Store (buffer memory)

Caches Data packets

/parc.com/videos/summer.mpg/v1/s0

4/18

Illustration of CCN work

Effect of in-network caching (content store)

A

B

D E

H I

Client 1 Client 2

A

B

D

H G

snu.ac.kr / video1.avi

5/18

Interest

Data

Mobility Support in CCN

Supporting subscriber mobility is relatively easy

Due to CCN’s receiver driven nature, consumers can retransmit

interest after establishing new connectivity

How about publisher mobility?

Need FIB update

Mobile broadcasting

Mobile chatting

Interaction application

6/18

Main Challenges

Maintain a valid path to the mobile publisher

Path towards mobile publisher always needs to be valid

Outdated FIB entry cannot be used

Fast FIB establishment

To forward interest packets correctly, FIB should be updated as

soon as possible

Cannot rely on the routing protocols (e.g., OSPF, RIP) due to longer

convergence time

… while preserving CCN architecture

7/18

Related Work

Mobility support in content centric network (Do-hyung Kim, et al. KAIST, ICN2012)

A content provider mobility solution of named data

networking (Xiaoke Jiang, et al. Tsinggua university, ICNP 2012)

DNS-like control server matches name & location

which may cause…

Scalability issue

• Single point of failure

• Bottleneck problem

Indirection delay

Name / Location coupling

violate the ICN philosophy

When you move,

you change your address

8/18

PMC Overview

Goal: support a Publish Mobility in CCN (PMC)

Design principles

No central entity dealing with mobility

Do not use location information

Do not violate the philosophy of CCN architecture

Our approach

Maintain two types of entries in FIB

Handle mobility event (using Interest / Data packet )

9/18

PMC: FIB maintenance

Original entry and Mobility entry in FIB

Original entry

Ordinary entry for stable and long-lived destination

Maintained by routing protocol

Mobility entry

Special entry for mobile and temporal destination

Maintained by PMC Relatively high priority (with short-timer

value)

Name prefix Original entry Mobility entry

snu.ac.kr interface-A interface-B

… … …

10/18

PMC: mobility handling (1/2)

PMC router

Handles publisher’s mobility event

FIB update

Home router of publisher

PMC router that announces original entry for publisher’s prefix

Mobile publisher

Produce the (real-time) content

Send a special Interest packet to maintain the mobility entry

Publisher URL/mobilityReport/Home

Publisher URL/mobilityReport/PrevPoA

11/18

* PoA: point of attachment

PMC: mobility handling (2/2)

12/18

PMC operation (Home New PoA)

• Mobile publisher reports mobility

event to the previous PoA (home

router) with Interest packet

• Data packets are sent back &

inter-nodes updates FIB

(mobility entries)

• Home router forwards stored

Interests to the publisher

• Following Interest packets are

forwarded along the new path

(1) Mobility event

(2) Mobility

report

(4) Content

download

(3) Data &

FIB

update

(/AliceNews.kr)

snu.ac.kr/AliceNews/MobilityReport/Prev

PoA

13/18

PMC operation (PoA New PoA)

• Mobile publisher reports his

mobility to Home router &

previous PoA

• Data packets are sent back &

inter-nodes updates FIB

(mobility entries)

• Home router and PoA forwards

stored Interests to publisher

• Following Interest packets are

forwarded along the new path

(/AliceNews.kr)

(1) Mobility

event

(2) Mobility

report

(3) Data &

FIB update

(4) Content

download

snu.ac.kr/AliceNews/MobilityReport/Home

snu.ac.kr/AliceNews/MobilityReport/Prev

PoA

14/18

Simulation Environment

Topology

Home router exists in ISP

hand-off occurs in single ISP

Comparison schemes

PMC

Indirection

Uses a DNS-like mobility

management server

Event-driven simulator

Parameters

CS size: 10 GB

FIB size: 10,000 entries

PIT timer: 3,000 ms

Interest packet size:

125 byte

Chunk(content) size:

2500 kbyte

Request term: 3,000 ms

Reference for parameters setting: - An effective hop-by-hop Interest shaping mechanism

for CCN communications, NOMEN 2012

- CCNx project ( www.ccnx.org )

Alice

Bob

HR

HR

ISP2

ISP1

Pure-CCN

15/18

Evaluation Result (1/2)

Chunk delivery delay

delivery delay =

retrieval time of the data packet - issuing time of the initial interest packet

PMC shows shorter handover delay than Pure-CCN

Indirection is stable. But, overall delay is longer than PMC Handover

delay

16/18

Chunk retrieval rate

Sequence number of received data packet

PMC can meet delay-critical QoE service

i.e., voice in a wireless context has one way delay requirement

of 200~250ms

Evaluation Result (2/2)

- Publisher mobility decreases the

retrieval rate of Pure-CCN

- Indirection shows low retrieval rate

due to the indirection delay

(bypassing)

- PMC shows stable retrieval rate

since it handles mobility event quickly

17/18

Conclusion & Future work

Supporting publisher mobility is one of key challenge to

adapt CCN into real world application these days

PMC suggests fast FIB update method to support

publisher’s mobility in CCN

Future work

Fast flooding scheme to support mobility event

Managing mobility between different ISPs

18/18

Thank you

19/18