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Experimental Evaluation ofContent Distribution with NDN

and HTTPAuthors: Haowei Yuan and Patrick CrowleyPublisher: 2013 Proceedings IEEE INFOCOMPresenter: Chia-Yi Chu

Date: 2013/08/14

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Introduction Experimental Setup File Distribution Performance Improving CCNx Performance

Outline

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Name-centric network architectures◦Data requests need to have unique names◦ In-network storage elements that can cache the data and

respond to matching requests. Named-Data Networking (NDN)◦ Interest packets

containing the name of the requested content

◦Data packets containing both the name and its associated data

◦NDN routers cache Data packets Entries in a cache indexed by their names.

Introduction (1/2)

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HTTP infrastructure◦URLs are the names that matter most in today’s Internet.◦ The requested URL in the HTTP header is the content name.

Including both web servers and caching proxies, can be viewed as providing in-network storage for named HTTP data.

Evaluate the effectiveness of NDN and HTTP as content distribution systems over a range of experimental scenarios.

Introduction (2/2)

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Test bed◦Open Network Laboratory (ONL)◦ 48 single-core machines

AMD 2.0GHz Operon Processor, with 512MB memory and 1Gbps network interface

◦Connected via virtual switches Network Processor-based Routers (NPRs)

Experimental Setup (1/3)

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CCNx Software Tools◦ ccnx-0.4.0, release on Sep. 15, 2011.◦ ccnd daemon

Configured with default underlying transportation protocol is TCP

◦Built-in ccncatchunks2 Generate a sequence of Interest packets

◦ ccnfileserver Generate Data packets with content fetched from files on server

Experimental Setup (2/3)

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HTTP and Web-Caching Software Tools◦ Lighttpd-1.4.28◦ Squid-3.41.11

Both using default configurations

◦wget For downloading files

Experimental Setup (3/3)

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The metric◦Download Time (DT)◦ the time from when a client application sends a request for a

file until the file is downloaded completely.

File Distribution Performance (1/11)

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Experimental Configuration◦ 40 client hosts, 1 server, and 2 levels of intermediate nodes◦ 8 clients form a cluster, and shared a common second level

intermediate node◦Connected via 1Gbps links◦ 100MB file is stored in server, clients try to fetch file

simultaneously

File Distribution Performance (2/11)

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File Distribution Performance (3/11)

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CCNx vs. Lighttpd◦ downloading 100MB file◦without a caching proxy◦ Start with 1 client in each cluster◦Active 1 clients each round until all clients are active

File Distribution Performance (4/11)

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File Distribution Performance (5/11)

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CCNx vs. Squid◦ Single level case

all the clients connect to the server through the top level CCNx router or Squid proxy

◦ Two level case clients are connected via a second level cache

File Distribution Performance (6/11)

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File Distribution Performance (7/11)

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Lossy Network Condition◦Emulate a lossy link

Rand drop plugin, which probabilistically selects and drops packets on the NPRs.

◦Emulate delay Delay plugin to an NPR connected with the link.

◦ 1 MB file

File Distribution Performance (8/11)

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File Distribution Performance (9/11)

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File Distribution Performance (10/11)

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File Distribution Performance (11/11)

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CCNx employs an XML encoding scheme to encode packets to wire format.

The original CCNx implementation ◦ stores content with their names encoded in the Content Store

(CS)◦when the CS is queried, several content names might need

to be decoded A simple change ◦ decoded content names are stored in the CS.

Improving CCNx Performance (1/2)

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Improving CCNx Performance (2/2)