Protocol Analyser basics | RS232,RS485,I2C,HTTP protocol sniffer

This page covers protocol analyzer basics and applications of protocol analyzer used for protocol analysis of various interfaces such as RS232, RS485, I2C, HTTP etc. It is also referred as protocol sniffer.

Protocol Analyzer Basics

Protocol Analyzer is the equipment used to perform protocol analysis. It is not limited to one particular standard or technology or interface type. It is applied to multiple standards/technologies and used for multiple interfaces viz. RS232, RS485, I2C etc.

Protocol Analyzer
Figure-1: Protocol analyzer

For example in GSM system, protocol analysers are connected with BTSs, MSCs and BSCs which will capture the traces in the case of failures at these sub systems for debugging and troubleshooting. The logs captured are provided to central office locations which will be used by software and or hardware team for further analysis. The log analysis is done either manually or using software tools.

Logs captured using protocol analyzer will help in offline analysis of the system. It is not feasible to have it placed at all the network interfaces to capture the logs due to higher cost.

Protocol Analyzer Features

•   Does measurements from lower to higher level and hence help analyze complete traces of the call.
•   Additional software applications help analyze the captured logs quickly.
•   can be customized easily for any standards/technologies with modifications in the protocol stack.

Models 4951C & 4952A from Hewlett Packard are popular protocol analyzers for analysis of Async, SDLC or NRZI, BSC, HDLC, SNA, X.25, DDCMP and other user defined protocols. It will allow user to monitor and to decode data transmission locally as well as remotely using LAN interface. It supports 19.2kbps asynchronous and 64kbps synchronous interfaces.

Modern day wireless systems are composed RF, layer-1 (physical layer), MAC layer and Upper layers (TCP/IP or UDP/IP) and application layer protocols. It is not easy to trace out the problems so easily using RF test and measurement tools and hence low level protocol analysis using protocol analyzer is a must. Figure depicts RS232 based protocol analyzer.

Protocol Analyzer Applications

Protocol Analyzer is used in many systems for protocol analysis and troubleshooting while implementing protocol stack. Systems having RS232, RS485, I2C interfaces are among them.

Test and Measurement Equipments

This section covers test and measurement equipments for WLAN, WiMAX, zigbee, Bluetooth, GSM, UMTS, LTE and more standard based device testing. It covers spectrum analyzer, VSG, VSA, frequency counter, protocol analyzer, AWG, digitizer, function generator, pulse generator, RF network analyzer, power meter, logic analyzer and more.

Test and Measurement Equipments
BER Testing equipments
Agilent T & M Solutions
Anritsu T & M Solutions
Rohde & Schwarz T & M solutions
wireless channel emulator
Vector signal generator
Vector signal analyzer
Power Analyzer Equipments
Protocol Analyzer

RF and Wireless Terminologies