RApid Model Parameterization (RAMP)

Issue

The utility of simulations and analysis heavily relies on good models of network traffic. However, the constantly-changing and decentralized nature of the Internet makes it difficult to model and simulate the Internet traffic.

What is RAMP

RAMP is a tool that allows people to quickly parameterize traffic models from measurements. Currently RAMP supports Web and FTP.

Input of RAMP

A libpcap-format trace file.

Output of RAMP

A set of CDF (Cumulative Distribution Function) files that model the traffic. Specifically, the CDF files consist of two types of data. One set of CDF files model application-level statistics of the traffic. Currently RAMP supports Web and FTP traffic. Each CDF file characterizes the probability distribution of one particular parameter in Web and FTP model. The other set of CDF files model path characteristics of the network. In particular, we focus on characterizing RTT and bottleneck bandwidth of the measured traffic since they are important parameters for driving network simulation.

Parameters of Web traffic model includes:

(a) user session inter-arrival time
(b) number of pages per user session
(c) page inter-arrival time
(d) page size
(e) object inter-arrival time
(f) object size
(g) client request size
(h) ratio between persistent and non-persistent connection
(i) server popularity          
(j) TCP window size

Parameters of FTP traffic model includes:
(a) user session inter-arrival time
(b) number of files per user session
(c) file inter-arrival time
(d) file size
(e) server popularity          
(f) TCP window size

Usage of RAMP

./RAMP [tcpdump trace] [threshold] [network prefix]

                 [tcpdump trace] : tcpdump trace file generated using tcpdump -w option
                 [threshold]     : the threshold time value (in millisecond) in Web traffic,
                                   that distinguishes idle periods in order to infer
				   user "think time" between requests for new top-level pages.
                 [network prefix]: network prefix used to distinguish inbound vs. outbound traffic

example: ./RAMP tracefile 1000 128.9.0.0/255.255.0.0

The tool is available here. It is also included in current ns release.