Authors: Haowei Yuan and Patrick Crowley Publisher: 2013 Proceedings IEEE INFOCOM Presenter: Chia-Yi Chu Date: 2013/08/14 1

 Introduction  Experimental Setup  File Distribution Performance  Improving CCNx Performance 2

 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. 3

 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. 4

 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) 5

 CCNx Software Tools ◦ ccnx-0.4.0, release on Sep. 15, ◦ 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 6

 HTTP and Web-Caching Software Tools ◦ Lighttpd ◦ Squid  Both using default configurations ◦ wget  For downloading files 7

 The metric ◦ Download Time (DT) ◦ the time from when a client application sends a request for a file until the file is downloaded completely. 8

 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 9

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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 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 13

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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 15

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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. 19

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