A content delivery network or content distribution network (CDN) is a large distributed system of servers deployed in multiple data centers across the Internet. The goal of a CDN is to serve content to end-users with high availability and high performance. CDNs serve a large fraction of the Internet content today, including web objects (text, graphics, URLs and scripts), downloadable objects (media files, software, documents), applications (e-commerce, portals), live streaming media, on-demand streaming media, and social networks.
In this research we are evaluating Performance Analysis of content delivery network with non-content delivery network. We will analyze the behavior and characteristics of content delivery network (CDN) with non-content delivery network (non-CDN) on the basis of these parameters. All the simulations are performed on network simulator 2 (ns2).
- Round Trip Time (RTT) for TCP based traffic
- Congestion Window behavior (cwnd) Analysis for TCP Traffic
- End to End Delay for TCP based traffic
- End to End Delay for UDP based traffic
- End to End Bandwidth Usage Analysis
Simulation Model for Non Content Delivery Network (Non-CDN)
We created the following simulation model with eight network (routing) nodes, one server and ten users connecting to the server. Users are connected to SW1 with 10Mb of link capacity (bandwidth) and 10ms of delay. While routing nodes bandwidth and delay are mentioned in the model. Server has 10Mbit of link bandwidth with 50ms of delay.
In this simulation all the 10 users are trying to connect to their target server (in this model which is located at the right). All users using TCP (FTP) and UDP (CBR) traffic type.
Some of the TCP and UDP protocols details are below.
- TCP Window Size: 8000 Bytes
- TCP Packet Size: 1000 Bytes
- UDP Packet Size: 500 Bytes
- UDP Packet Interval: 0.01 sec
Network with CDN Nodes
For the purpose of comparative analysis of Network with CDN enabled network. We introduce one more server which is actually our CDN node located nearby users proximity. In the first scenario let say users reside in Karachi (Pakistan) and they are hitting youtube server located somewhere in USA. While with CDN capabilities one of the CDN enabled youtube server must be residing in Pakistan or Asia.In this simulation now users requests will be directed to CDN server irrespective of original Server which is located 8 hops distance.
Comparison of Round Trip Time Analysis for TCP Connections
Comparison of Congestion Window (cwnd) Behavior CDN and Non-CDN
Comparison of End to End Delay for TCP Based Traffic (CDN/Non-CDN)
Comparison of End to End Delay for UDP Based Traffic (CDN/Non-CDN)
Comparison of Total Bandwidth Usage Analysis for CDN/Non-CDN
The simulation and corresponding data analysis has proved that deploy Content Delivery Network (CDN) is much beneficial for End users and the Organization itself.
- End User observes quicker and faster response to its requests
- Less delay and jitter in real Time video and voice streaming
- Better response of TCP round trip time
- Less Congestion in the network thus increases Quality of Service (QOS)
- Network bandwidth wastage can be reduced with the help of CDN
- Reduced end to end delay thus better throughput
About the Researcher:
Engr. Anjum Nazir is an independent researcher and Linux Enthusiast, member and pioneer of LDS (Linux Development Society). He received his engineering degree from Sir Syed University of Engineering and Technology and Masters from Muhammad Ali Jinnah University Karachi. By profession he is Information Security Consultant, trainer and blogger. You can reach him through his blog site www.geeks-hub.com or hit him on anjum at geeks-hub dot comPerformance Analysis of Content Delivery Network (CDN),