Modern protocol analysers are packed with new functions, capabilities and easy-to-use features

These protocol analysers help in speedy analysis and troubleshooting. They can also provide statistics on the traffic, which helps to identify trends that may lead to problems with the network in the future

By Richa Chakravarty

Tuesday, September 16, 2014: Protocol analysers are primarily used for troubleshooting and debugging on networks—to figure out the cause of performance issues in communication or data transfer in wired or wireless modes. By combining hardware and software, protocol analysers capture and analyse signals and data traffic.

What’s new in the market

With the advances in the networking and communication segment, protocol analysers are also evolving fast and going beyond just their packet-capture capabilities. Modern protocol analysers are packed with new functions, capabilities and easy-to-use features that help in speedy analysis and troubleshooting. The advanced protocol analysers can also provide statistics on the traffic, which helps to identify trends that could cause problems with the network in the future.

Protocol analysers integrated with multiple instruments: Most manufacturers today offer instruments that have inbuilt protocol analysers. These are widely used in different segments, right from packet analysers to IP load testers. Scientech Technologies has recently launched a compact mixed signal oscilloscope (MSO), the 700 series, which has an inbuilt protocol analyser, logic analyser and real time spectrum analyser. “The MSO 700 series is only as big as a match box. It is a complete test and measurement (T&M) package without any compromises on quality or features. It is supported with SPI, UART, I2C and CanBus software and is compatible with TTL and CMOS. It provides a sampling rate of about 40 Msps for accuracy,” informs Vivek Mantri, country manager, industrial segment, Scientech Technologies Pvt Ltd.

Protocal analysers integrated with network monitoring systems: A protocol analyser today has to enable service providers to monitor their networks from end to end, which means support for 2G, 3G and 4G applications. “The most advanced protocol analysers must also have tight integration with other network monitoring products such as an assurance tool,” says Silvia Wessels, strategic marketing manager, network and service enablement business segment, JDSU.

In March 2014, JDSU launched its xSIGHT assurance solution, which in combination with signaling analyser real time (SART) a classic product analyser for 2G, 3G and 4G evolution, addresses the modern line laboratory requirements. This solution addresses the modern live, laboratory requirements for comprehensive, real-time end-to-end troubleshooting. “xSIGHT maximises the return on investment by making the analyser a part of a larger and more comprehensive workflow, which pinpoints the source of the problem and the multiple places in the network where the problem is occurring, prior to having to use the protocol analyser,” says Silvia Wessels.

Integrating a large number of protocols: Protocol analysers today have the ability to keep up with the ever-increasing number of protocols and technologies, with features such as hierarchical displays, real-time statistics, protocol traffic summaries, detailed error reports, powerful test scripting and the ability to create user-defined test reports. One such product is the TLA7SA00 series launched by Tektronix, which is a logic protocol analyser module that provides an innovative approach to PCI express validation, which spans all layers of the protocol—from the physical layer to the transaction layer. Its powerful trigger and filtering capabilities provide the ability to quickly focus on the data of interest. It is a complete package of probing solutions targeted at various form factors and applications.

Portable protocol analysers: While enabling developers to monitor, capture and decode communication data, manufacturers are also offering them flexibility. Teledyne Lecroy’s new portable protocol analyser—Eclipse X34 MIPI M-PHY—is used for testing mobile computing products. Launched in March 2014, Eclipse X34 can monitor, capture, decode and analyse multiple transmission modes with different bit-signalling, clocking schemes and rates that support bandwidth ranges. The application display of this protocol analyser is highly configurable and can be modified to fit most users’ debugging styles. Eclipse can time-correlate its traces to other Teledyne Lecroy supported protocols and buses. Hence, this multi-protocol support makes it useful to help debug DDR memory and other serial protocols on low power devices.

Hardware-based protocol analysers: Instead of just software-based analysers, hardware-based protocol analysers with sophisticated PC user interfaces are becoming popular. Hardware analysers help in getting the real-time stamp for frames and, hence, provide a very realistic picture of what is happening on the bus and at what time. With increasing buffer space on hardware and fast communication interfaces with PC software, these tools can capture a good amount of traffic continuously even with a loaded bus. Hardware-based decoding features are also available on scopes based on protocol analysers and help overcome speed limitations.

Protocol analysers as a single-box tester: To keep pace with advanced communication and radio technology, protocol analysers are becoming more powerful so as to analyse and test complex network scenarios. These analysers can handle any application test, ranging from module tests to systems integration, regression, conformance, radio frequency and network operator specific tests. Hence, depending on the integration of the protocol layers, various approaches can be used for performing protocol tests. “While the focus of LTE chipset and wireless device manufacturers is on the basic functioning of the protocols on the air interface, and ensuring they comply with 3GPP specifications, engineers look at the performance aspects, e.g., the data throughput of LTE wireless devices that is measured under various propagation conditions. To meet these demands, the protocol analysers are configured dynamically to meet 3GPP test specifications or user definable test scenarios,” shares Balasekar Karthik, assistant manager, business development, Rohde and Schwarz India Pvt Ltd.

The R&S CMW500 protocol analyser by Rohde and Schwarz offers complete reference implementation of the protocol layers that are required for analysing the air interface of wireless devices. It supports both LTE and WLAN users as it can also do LTE-Wi-Fi offloading and co-existence tests. The box also has the in-built fading functionality, which helps in testing the fading scenarios without any additional instrumentation. “Being a single-box tester, it saves space and reduces investment costs. To simplify the generation of signalling scenarios even more, we offer ready-to-run scenarios derived from the collaboration with wireless device developers. These scenarios can be used as they are or as templates for expansions or changes. They are continuously being enhanced and adapted to the current features,” informs Balasekar Karthik.

How to choose the right product

When evaluating a protocol analyser, the user should decide whether to go for a portable or a distributed solution. A portable protocol analyser is suitable for bench testing. Portable solutions usually include the appropriate software installed on a laptop or PC. These solutions can only be run from stations that the licence permits. However, a distributed protocol analyser is designed to deploy solutions at strategic locations on the network and enable remote access to them.

One should also consider the speed of the data for which the protocol analyser will be used. The protocol analyser must keep up with the data speeds on the network to be analysed; otherwise the user will not be able to fully analyse and capture the information necessary to solve the designated problems.

Suggests Vivek Mantri, “The most important criterion for selecting a protocol analyser is to understand which protocols are supported, based on the end user requirements. Our analysers cover SPI, UART, I2C and CAN, which are standard protocols used in any industry. Software upgradation from time to time is also equally important, so that the user does not face problems related to product upgrades.”

While making a purchase decision, users generally go for high speed protocol analysers. These use special hardware and software to keep up with the data stream at Gigabit Ethernet and higher speeds. These advanced technologies add to the price of the protocol analyser but provide a powerful tool to investigate even the most annoying issues. Hence, users can ensure that the protocol analyser gives the best return on investment by making the device fit into the user’s network environment with a simple and easy-to-use workflow.

Protocol analysers are largely used to verify protocol compliance. So compliance to various standards is an important feature desired by engineers. Also, protocol analysers that can show the data just as it appears in the specifications will be of great help to engineers working on those protocols.