Load Testing. Nexus8610 Traffic Simulation System. How to ensure the Performance of the Network Element?

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1 Load Testing network element performance verification under stress conditions Nexus8610 Traffic Simulation System Load Testing How to ensure the Performance of the Network Element?

2 The Challenge A thorough assessment of the load handling capabilities of a network element is paramount for careful network planning. Verification of the proper behavior of the switching equipment before field deployment will ensure that no undesired reaction to heavy operating conditions will take place. Reactions include resetting of interfaces, rebooting of the system or dropping established connections. Such events dramatically affect the service, undermining customer satisfaction and often leading to a loss of image. Testing the capacity of a network element to endure heavy load conditions is therefore an obligation for manufacturers, prior to the commercial release of the product. Operators will also have to go through sessions of load testing, for instance before a new software release, as this will form part of the guarantee of the quality of the service to their end users. The Approach to Competitiveness New communication technologies have brought in a new level of competition among telecom service providers and equipment manufacturers. Short time-to-market has become a key success factor. An optimal test solution is therefore necessary to guarantee a high degree of quality from the deployment of a service. To meet stringent quality and performance requirements, while ensuring even shorter time-to-market, testing has to become more efficient and reliable. New quality management systems also require testing as an integral part of the defined processes, to be implemented in a systematic and reproducible manner. Load tests by nature put both network elements and test equipment under strain and must run for prolonged periods of time, including night time and weekends. Load tests are normally executed in specialized laboratories, employing highly skilled personnel, with long established procedures and an impressive installed base. All this calls for an adaptable and reliable test system that can easily be integrated in an existing environment and that offers high performance, remote control and 24x7 type of availability. Application note Page 2

3 Figure 1 Nexus8610 Test Editor How the Nexus8610 Supports You The Nexus8610 Traffic Simulation System, one of the best performing and most versatile call simulators available today, is the answer to all these needs. As core network tester, the Nexus8610 is flexible, modular, scalable and, of course, reliable. Its flexibility allows the user to implement new tests speedily and easily. Nexus8610's modularity lets the user optimally configure the test system according to his needs without effort. Thanks to its scalability, the Nexus8610 can be expanded when the need arises with no limitations due to the system's architecture. Implementing a networked structure, the Neuxs8610 employs distributed Test Units, networked and controlled via one or more Nexus8610 Test Control Units. The Test Control Unit (TCU) is connected to the individual Test Units and HTM's via a LAN connection using Ethernet technology. This enables any number of 8610 Test Units (TU) and HTM's and their corresponding TCU's to be included in existing data networks. This is of particular importance in case of remote operation and when integrating the test platform into an existing automated infrastructure. Its multi-tasking operating system running on each board guarantees high performance benchmarks and no computing power shortage. Application note Page 3

4 Figure 2 Nexus8610 Test Monitor The Nexus8610 Traffic Simulation System uses OPTEC (OPtimized TEstcase Composer). This is the system language to create new test cases, to modify existing ones and to link them into test loops in an easy and efficient way. OPTEC provides a protocol library for every application. This library contains the full functionality of each specific protocol. OPTEC serves the purpose of abstracting the user from the details of the protocols, allowing the user to concentrate on the test's concepts. A wide protocol library underpins the OPTEC test composition and implementation, making it a powerful and flexible tool. Furthermore, the high level of detail provided in the fault reports makes it easy to detect any malfunction and then to proceed to resolve the problem. Figure 3: Nexus8610 OPTEC test case editor Application note Page 4

5 Nexus8610 Use Case The Nexus8610 is capable of performing load tests, functionality tests and Interworking tests simultaneously. These features enable the user to reproduce real life load conditions. Nexus8610 users have been able to reach a 95% degree of correlation between their test suite and real network behavior. Combining data traffic and signaling traffic in the right proportions and selecting the required interfaces from the wide range of protocols available, the network element can be subjected to the same operating conditions that will be later faced in the field. This effectively minimizes the risks of service failure. Needless to say, a bulk call generator is just not capable of the same functionality and will give no information as to where the faults occur. In the use case shown in Figure 4, the Nexus8610 simulates to behavior of all involved parties in order to verify whether the System Under Test (SGSN GGSN) is capable to manage 3G and 2G mobile subscribers moving from one technology area to the other. Simulating thousands of mobile subscribers simultaneously on the GPRS Gb and the UMTS IuPS interfaces allows putting the System Under Test under heavy load and verifies its behavior under load. Nexus8610TU3 SGSN GGSN IuPS 2G - 3G Ho 3G -2G Ho Gb Gf Gd Gc Gi Nexus8610TU Figure 4: Nexus8610 to verify 3G 2G / 2G 3G Handovers under various load conditions The Test Automation suite allows simultaneous control of the equipment under test and the test suite, allowing the user to reach a 24X7º use of the test resources. Maximizing utilization of these resources leads to a better use of skilled manpower, a short investment payback period and shorter time to market. Application note Page 5

6 Summary The Nexus8610 Traffic Simulation System is truly the comprehensive solution to the problem of load testing. And not only load testing, it also provides for feature testing and interworking testing at the same time. Its architecture guarantees the capability to grow according to the user's requirements. Its modularity enables it to be tailored to meet those requirements. Within the Nexus8610 programming environment, ease of use is guaranteed by OPTEC. Test cases for performance, load and functional features can be written, executed and verified within minutes, allowing a considerable increase in the productivity on the test floor. OPTEC test cases use the familiar notation of the technical specifications, and are thus easy to read and write. An impressive range of applications and protocols, spanning from wireline telephony, Intelligent Network and Voice over IP up to third generation mobile communications, is available for the Nexus8610 Traffic Simulation System. Furthermore, supported by the open platform, the modular approach of the system and OPTEC, Nexus can implement new applications within a very short period of time. Use of the Test Automation application, which efficiently coordinates the system under test and the Nexus8610, boosts resource utilization, minimizing costs and improving test schedules and planning. Application note Page 6

7 Notice Every effort was made to ensure that the information in this document was accurate at the time of printing. However, information is subject to change without notice, and Nexus Telecom reserves the right to provide an addendum to this document with information not available at the time that this document was created. Copyright Copyright 2005 Nexus Telecom. All rights reserved. No part of this guide may be reproduced or transmitted electronically or otherwise without written permission of the publisher. Trademarks Nexus Telecom and its logo are trademarks of Nexus Telecom AG. All other trademarks and registered trademarks are the property of their respective owners. Revision History Version Date Author 2.0 May 2005 Franz Neeser All General Inquiries: Nexus Telecom AG System Solutions Feldbachstrasse 80 P.O. Box 215 CH-8634 Hombrechtikon Switzerland Tel Fax Nexus Telecom AG Wireless Network Systems Muertschenstrasse 27 P.O. Box 1413 CH-8048 Zürich Switzerland Tel Fax Nexus Telecom (Americas) Inc. (NA and CALA) Suite Prince of Wales Drive Ottawa, Ontario Canada K2C 3W7 Tel Fax Application note Page 7