Network Performance Measurement 1 2 3 4 5

Network Performance Measurement 1. 2. 3. 4. 5. Introduction Classification of Measurement. Tools and Techniques. Examples. Conclusion.

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

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

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

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

Techniques n Tcpdump/Windump Packet Capture. n Supported by PCAP / JPCAP APIs. n n Explained in Java Program. n Filters…. . n Protocol – TCP/UDP, 802. 3, ICMP etc. n Count n Boolean Expressions. – Examples. n Interface. – eth 0, hme 0 etc.

TCPDUMP… n Examples: n tcpdump host 1 n To print all packets arriving at or departing from host 1: n tcpdump host 1 and ( host 2 or host 3 ) print traffic between host 1 and either host 2 or host 3: n To n tcpdump ip host 1 and not host 2 n To print all IP packets between host 1 and any host except host 2: n More examples @: http: //www. tcpdump. org/tcpdump_man. html

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

Java program … 2 n Java Package: JPCAP methods used. n Provides an Interface and system for network packet capture. n JPCAP uses windump utility. n Constructor: n n n 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 n get. Device. List() n n set. Filter(String condition, Boolean optimize) n n Setting protocol/Expression for capturing packet. get. Packet() n n Returns Name of Device (Interface). Captures ONE packet at a time from Interface. loop. Packet(int count, Jpcap. Handler handler) n Count times capturing packet.

Java program …. 4 n Utility: Windump. n Tcpdump equivalent utility for Windows. n Uses a low-level library “winpcap” for packet capture. n Library: Winpcap n It is an architecture for packet capture and network analysis for Win 32 platforms. n It includes Kernel-Level packet filter, a Low-level DLL and High-level and system-Independent library (wpcap. dll). n Kernel: Windows Operating system.

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

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

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

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

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