Network Performance Measurement Introduction Classification of Measurement. Tools and Techniques. Examples. Conclusion.

Introduction. Parameters which measured are: High Bandwidth. Bandwidth – Data transferred / time Delay - Time taken for data to transfer (App level) Packet Loss – Affects Throughput and Apps. High Bandwidth. Small Delay Low Packet loss

Classification of Measurement LAN , Backbone , End-to-End, Application Network Measurements. Backbone MRTG End-To-End (Machine to Machine) Tcpdump Ping / Traceroute

Tools Multi Router Traffic Grapher. Measures… load on network links (Edge-Routers). Network Traffic. System Load, Login Sessions, Modem availability Output…. HTML, LIVE presentation. Graphical Images.

Tools.. (MRTG) Internal Design.. Portability… Perl – Reads Traffic Counters of Router. C – Logs Traffic Data and Creates Output. SNMP – Perl Scripts reads SNMP variables. Portability… Unix (any) & Windows NT. Default Sample Time : 5 mins.

Techniques Tcpdump/Windump Packet Capture. Supported by PCAP / JPCAP APIs. Explained in Java Program. Filters….. Protocol – TCP/UDP, 802.3, ICMP etc. Count Boolean Expressions. – Examples. Interface. – eth0, hme0 etc.

TCPDUMP… Examples: tcpdump host host1 To print all packets arriving at or departing from host1: tcpdump host host1 and \( host2 or host3 \) To print traffic between host1 and either host2 or host3: tcpdump ip host host1 and not host2 To print all IP packets between host1 and any host except host2: More examples @: http://www.tcpdump.org/tcpdump_man.html

Java Program - Windump by Hung Application Architecture Hierarchies Application Java program which uses JPCAP methods and captures packets. Performs Analysis on the captured packets. Uses JDBC and stores results in mySQL database.

Java program …2 Java Package: JPCAP methods used. Provides an Interface and system for network packet capture. JPCAP uses windump utility. Constructor: Jpcap(String device, int snaplen, Boolean promisc, int to_ms); “device” : interface for capturing data “snaplen” : Maximum # of bytes captured per packet. “promisc” : Allows network device to intercept and capture packet. “to_ms” : Time out limit

Java program –(Methods)…3 getDeviceList() Returns Name of Device (Interface). setFilter(String condition,Boolean optimize) Setting protocol/Expression for capturing packet. getPacket() Captures ONE packet at a time from Interface. loopPacket(int count, JpcapHandler handler) Count times capturing packet.

Java program ….4 Utility: Windump. Library: Winpcap Tcpdump equivalent utility for Windows. Uses a low-level library “winpcap” for packet capture. Library: Winpcap It is an architecture for packet capture and network analysis for Win32 platforms. It includes Kernel-Level packet filter, a Low-level DLL and High-level and system-Independent library (wpcap.dll). Kernel: Windows Operating system.

Java program….5 1 Begin Connect to mysql database Select database use check data tables. 1 create packet data table if needed

Insert packet data into Database Java Program…6 1 Get “number” of Packets. Connect to database End Insert packet data into Database Get packet Data

Java program….7 Analysis… TTL – Values must be equal for packets with same S/D. Flow - # of S/D pair of packets per unit time. Delay – Time stamps of consecutive packets.

Java program….8 Limitations… Improvements…. Passive Monitoring. Non Client-Server Architecture. Improvements…. User Given parameters – More Flexible. Client-Server based – “network-as-a-whole” TCPDUMP – platform independent. GUI

Conclusion… Network Performance can be measured at various levels. Net. Performance can be implemented in various ways..using various tools.