The Most Sophisticated And Versatile Interworking Test Solution

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The most sophisticated and versatile Interworking Test Solution for Converged Networks and appropriate Network Elements Nexus8610 Traffic Simulation System “ and Convergence becomes true ” Nexus8610 The telecommunications industry is undergoing a fundamental shift in technology. Service providers continue to build global networks based on IP. There are different drivers for this movement such as lower capital expenditures, reduced operational costs and opportunities to generate new revenues. The carriers are upgrading their voice circuit networks to open, distributed, and highly scalable packet telephony networks. Figure 1: Convergence – from 3G Mobile to Analog POTS Developing, operating and maintaining converged networks in order to provide new services such as requests to take care about the following aspects: New types of network elements are required in order to merge different technologies (see Figure 1): Media Gateway Controller (MGC) Media Gateway (MGW) Circuit Switched and Packet Switched technologies need to interwork on control-plane and user-plane level. The service quality offered to the end-user must not be affected by operating a converged network. These aspects require for suited test tools that support Manufacturers of network elements: to carefully test their network elements in different phases of the product life cycle (Development, System Integration Nexus8610 Page 2 Nexus8610 and Acceptance) prior the delivery to their customers. Operators of converged networks: to carefully test new SW releases and new services prior their deployment into the life network in order to avoid disruptions and malfunctions of the real network. There are three groups of test methods that are widely used within the communication industry: Functional tests verify whether a network element can perform such basic functions as message forwarding and error detection correctly. Functional tests also examine interworking issues, such as appropriate responses to a network problem or the proper implementation of a new service. Acceptance and Regression tests verify that the original functionality continues to be maintained when new functionality or patches have been implemented. These tests can be executed more efficiently using test automation that can be utilized 24 x 7 to produce dramatic cost savings and accelerate time-to-market. Load tests investigate the behavior of the network element under different traffic load conditions. Nexus8610 Traffic Simulation System offers all the features and testing capabilities needed to support all three types of tests. It has especially been designed for testing of core network elements as well as an End-toEnd test solution in a lab environment. Highlights Nexus8610 performs powerful testing capability of the control-plane and user-plane. Nexus8610 performs user-plane tests such as Sending / receiving Single Tones Tone cadence detection Sending / receiving bit patterns Sending / receiving voice prompts available as *.wav file Measuring of Speech Quality with PAMS, PSQM / PSQM+ and PESQ algorithm on all interfaces Measuring of QoS parameters on Ethernet based application. Speech recognition allows verification of voice prompts sent by the SUT. Nexus8610 Page 3 Nexus8610 Nexus8610 performs functional, load, acceptance and regression tests. Test Automation application automated 24x7 testing. optional for fully The Nexus8610 performs the principal testing methods needed to verify that features and functionalities in any SUT are implemented correctly. The behavior of the SUT can be tested with only a few subscribers, or under real traffic conditions by simulating thousands of subscribers in parallel. Nexus8610 offers multi-user capability in a networked system. Different users can test multiple interfaces and protocols simultaneously to optimize the use of the Nexus8610, resulting in dramatic cost savings and accelerated time-to-market. Unique user-plane testing and connection verification capabilities Unique load generation and load handling capabilities Fully scalable platform with multi-interface and multiprotocol testing capability. Independent processing resources in each hardware test module for scalability. Flexibility of the OPTEC method for writing test cases. OPTEC supports fast and efficient test case generation without requiring programming skills. The versatility of the Nexus8610 allows testing of the control-plane and user-plane of media gateways and media gateways controllers, as well as the testing of any interworking behavior with other technologies such as UMTS, GPRS, GSM, SS7, CAS, ISDN, and Analogue POTS. On the user-plane the speech quality of individual connections can be analyzed using standardized algorithm such as PAMS, PSQM (ITU-T P.861) or PESQ (ITU-T P.862). Nexus8610 Page 4 Nexus8610 Nexus8610 - System Features and Functionality Test Monitor The Test Monitor (see Figure 2) of the Nexus8610 is used to control the execution of tests. • Load - loads a previously created executable test scenario. • Start - starts test execution, various modes are provided such as Single test execution, all test cases of the test scenario are executed in accordance with the user defined sequence once Non-stop, repeated test execution, all test cases of the test scenario are executed in accordance with the user defined sequence until execution is stopped by the user Manual execution of singe test cases in accordance with the user defined sequence. • Stop - terminates test execution when the currently running test case has been terminated • Release - terminates test execution with immediate effect without finishing the currently running test case. Figure 2: Nexus8610 - Test Monitor window Beside test control functionality, there functionality provided by the Test Monitor. is further • Emulator - supports manual testing of one or more simulated subscribers without interrupting the execution of the reminder of the test. • On-Line results – report of various user definable counters while test execution. Nexus8610 Page 5 Nexus8610 • Audio Monitor - allows audio access to any established speech path in order to listen to a specific call. The audio signal is played by the loudspeaker of the Nexus8610 TCU (Test Control Unit). Wavetool The Wavetool allows generating any kind of tones (singe tones, DTMF tones, multi frequency tones etc) to be used in OPTEC test cases for inband signaling or speech path verification. The tone is defined by the level and frequency. Once a tone is generated it is stored as *.wav files in the Nexis8610 database and can be re-used later on again. In addition to the tone generation, the Wavetool also supports recording of any kind of voice prompts via the microphone that can be connected to the Nexus8610 TCU. Figure 3: Wavetool – to generate any kind of tones Interworking Testing The Nexus8610 system architecture supports simultaneous testing of different OPTEC applications. The SUT can therefore be tested without having to include real network elements in the test what results in heavy cost savings. This unique capability makes the Nexus8610 the most versatile test solution for Functional, Interworking and Load testing on the market. Nexus8610 Page 6 Nexus8610 Nexus8610 User-plane testing capabilities Nexus8610 is well recognized for its strong user-plane testing capability. Nexus8610 supports different methods for testing the user-plane. Speech path verification Nexus8610 tests any speech path, established between any of type of interfaces by sending and receiving single tones, DTMF or other tones from calling side to called side and vice versa. The user can define the cadence (on-time and off-time) in steps of 10ms. The level and frequency / frequencies of a test tone is defined when the test tone is generated with the Wavetool. (see Figure 4). • Example: The user writes an OPTEC test case for the following tone sequence that shall be send on the “calling” party side and received at the “called” party side Tone-on with frequency f1 [Hz] for the duration Ontime 1 [ms] with level 1 [dBm] Tone-off for the duration Off-time 1[ms] Tone-on with frequency f1 [Hz] for the duration Ontime 2 [ms] and level 2 [dBm] Tone-off: for the duration Off-time 2 [ms Tone-on with frequency f2 for On-time 3 [ms] and level 3 [dBm] level [dBm] the duration f2 level 3 level 2 f1 f1 level 1 Off-time2 Off-time1 On-time1 On-time2 On-time3 Figure 4: Test tones – Level, Frequency, Cadence and Tolerance Nexus8610 Page 7 Nexus8610 Sending / Receiving *.wav files Nexus8610 performs one process per HW test module to send (encode) – receive (decode) any kind of voice prompts that is available as *.wav file. The number of processes that is performed sequentially per HW test module is not limited. Channels not used for sending – receiving *.wav files can be tested with tones or bit patterns in parallel. Sending / Receiving *.wav files is supported on Ethernet, TDM, ISDN BA and POTS based OPTEC applications. The capability to handle *.wav files The different types of codecs (G.711, G.726, G.729 etc) that are used in converged networks are optimized for encoding / decoding of human voice pattern but not for single or MF tones. Providing the capability to handle *.wav files in addition to test tones for speech path verification is an essential feature. With the Audio Monitor the user can directly verify the sound of a voice prompt by accessing the related voice channel. Speech Recognition The importance for the recognition of voice prompts as part of a test procedure becomes more and more important: • There are more and more voice services deployed in communication networks. • Manufacturers of Network Elements supply their network elements to customers allover the world. As a matter of fact, these Network Elements have therefore to provide announcements in various languages. Having a test tool capable to recognize spoken prompts reduces the effort to test this functionality on the SUT dramatically. On the Nexus8610, the principle of the Speech Recognition is based on the approach to compare voice prompts (e.g. “The mobile subscriber can not be reached at the moment”) as part of an OPTEC test case. Nexus8610 Page 8 Nexus8610 For recording the voice patterns, two different methods are supported: • Method 1: The reference pattern is recorded from the SUT. The Wavetool supports recording of voice prompts. For recording, the appropriate test case must be executed manually and the voice pattern can be recorded using the Wavetool. The recorded voice pattern is converted then into a signature file, a sequence of 20ms in length. This signature file can be integrated in any OPTEC test case. • Method 2: If the file format of the voice pattern used in the SUT is available as a *.wav file it can directly be imported into Nexus8610 using the Wavetool. The signature file then is calculated equally to method 1. Nexus8610 is capable to learn up to 64 different voice prompts per test, each of up to 120 seconds in length. Per HW test module processing of up to 8 parallel operations is supported. Speech Recognition is supported on 3G/2G Mobile, VoIP and PSTN applications. Speech Quality Analysis The principle of Speech Quality Analysis is based on the comparison of a reference ASTS (Artificial Speech Test Sample) file with an ASTS file that has been send through the SUT. An ASTS is a mixture of male, female and infantile utterances used to simulate the real voices of a phone call. On its way through the SUT the content of the ASTS file might get degraded due to technical influences caused by the SUT such as Encoding – decoding according different coding rules Conversion from circuit switched technology (e.g. 64kbps bearer channel) to packet switched technology (e.g. RTP packets) and vice versa As a result of the comparison of the two ASTS files, beside many other parameters, there is the MOS (Mean Opinion Score) score. This value gives an indication about the quality of a single connection. ITU-T P.800 defines the MOS score range as following: 5 excellent 4 good 3 fair 2 poor 1 bad Nexus8610 Page 9 Nexus8610 The following list shows some typical MOS score rates for different codecs. Codec Bit rate (kbps) MOS score G.711 64 4.3 G.723 6.3 3.8 G.726 32 4.0 G.728 16 3.9 G.729 8 4.0 GSM FR 13 3.7 Depending on the chosen algorithm the following parameters are calculated as results PSQM score [5..0] PSQM+ score [5..0] PESQ Score [5..0] and many more (see also Figure 6) Nexus8610 performs one Speech Quality Analysis measurement (see Figure 5) at the time per HW test module. The number of Speech Quality Analysis that is performed sequentially per HW test module is not limited. Channels not used for Speech Quality Analysis can be tested with tones or bit patterns in parallel. Speech Quality Analysis is supported on 3G/2G Mobile, VoIP and PSTN applications. The following algorithm are supported • PAMS • PSQM / PSQM+ according to ITU-T P.861 • PESQ according to ITU-T P.862 The implementation of the Speech Quality Analysis in the Nexus8610 is shown in Figure 5. The ASTS is stored in the Nexus8610 and becomes part of the appropriate OPTEC test case when the speech quality shall be analyzed. The reference ASTS file is encoded according to the chosen codec and sent through the SUT. At the receiving side, the degraded ASTS is decoded according the chosen codec into the same format as the reference ASTS file. Both files are compared than using one of the algorithms PAMS, PSQM or PESQ. Nexus8610 performs speech quality analysis on all supported interfaces. Nexus8610 Page 10 Nexus8610 - MOS rate - SQA val ASTS ASTS Degraded file is decoded and compared with Reference file Nexus8610TU3 ASTS reference file is sent as payload GMM RANAP AAL2 SIG SCCP Payload TC Payload TC MTP-3B MTP-3B SSCF-NNI SSCF-NNI AMR codec SSCOP SSCOP IuUPP AAL5 AAL5 AAL2 RTCP RTP Signaling TC SIP UDP SDP TCP IPv4 / IPv6 ATM Ethernet STM-1 IuCS SUT RTP Figure 5: Nexus8610 - Speech Quality Analysis of a 3G – RTP voice call For the Nexus8610, ASTS (Artificial Speech Test Samples) are available for British and American English. The results of the speech quality are presented on two levels (see Figure 6) An overview showing the total number of performed measurements and the number of measurements per chosen algorithm. To provide overall test results at a glance, the measured MOS rates are displayed in groups representing the MOS ranges 5-4, 4-3, 3-2 and 2-1. Detailed information as per speech quality analysis measurement showing all parameters. Figure 6: Nexus8610 Speech Quality Analysis – result presentation Nexus8610 Page 11 Nexus8610 Convergence Testing – Nexus8610 Use Cases Testing a MGW with Nexus8610 Testing a Media Gateway requires for a test tool that is capable to simulate different interfaces and protocols in parallel in order to replace the real network where a MGW normally is embedded. Figure 7 shows a test setup using Nexus8610 to simulate the complete environment around a MGW (Media Gateway). On the control-plane Nexus8610 acts as a MGC (Media Gateway Controller). On the user-plane, it provides the interfaces simulating different kind of networks such as PSTN (SS7, CAS), PLMN (UMTS, GSM) and PDN. With its strong user-plane testing capabilities Nexus8610 fits perfectly to tests the interworking functionality of the MGW. Nexus8610TU3 Nexus8610TU H.248 AAL2 RTP TDM AAL2 RTP TDM MGW Figure 7: Nexus8610 – testing a MGW Test issues Does the MGW properly convert encoded payload transported from CS (Circuit Switched) - to PS (Packet Switched) and vice versa? Do the different interfaces of the MGW correctly interwork? Does the MGW properly encode – decode payload using different kind of codecs? Does the Speech Quality of user-plane connections Nexus8610 Page 12 Nexus8610 vary when the different load profiles are applied to the MGW? Do the protection mechanism of the MGW work correctly if there are overload conditions on its control interface (H.248)? This test setup allows the following to be tested: The correctness of the H.248 / MEGACO implementation in the media gateway under different load conditions. The interworking of the CS and PS user-plane on different interfaces such as AAL2 channels (e.g. IuCS), RTP sessions and 64kbps bearer channels. Conversion of encoded payload according various types of codecs Any functionality implemented in the media gateway under varying load conditions Speech Quality Analysis on all simulated user-plane interfaces Verification of the correctness of announcements sent by the SUT. QoS Parameter verification on RTP and SIP While test execution, Nexus8610 provides audio access; the user therefore can directly listen into any call. With the optional application Test Automation, testing can be performed 24x7, enabling an optimized utilization of the test tool. Testing the combination MGC - MGW with Nexus8610 The Nexus8610 is not only strong in testing the userplane testing but also in testing the control-plane. These strengths make the Nexus8610 to the perfectly matching tool for testing a combination of MGW – MGC as shown in Figure 8. The Nexus8610 simulates the complete environment where the MGC – MGW is embedded in a life network. On the control-plane Nexus8610 simulates various types of signaling traffic (e.g. SS7, SIP/SIP-T), on the userplane the related payload is simulated using different kind of interfaces. Nexus8610 therefore acts as control-plane and user-plane simulator for various interfaces, protocols and technologies such as PSTN (SS7, CAS), PLMN (UMTS, GSM) and PDN. Nexus8610 Page 13 Nexus8610 With its strong user-plane testing capabilities Nexus8610 tests the interworking capability of the MGW. Test issues Does the MGW properly convert payload from - to CS to PS and vice versa? Does the MGW properly encode – decode payload using different kind of codecs? Does the Speech conditions? Quality dependent on load Does the MGC manage heavy load on the controlplane correctly? Do the protection mechanism of the MGW / MGC work as specified under overload conditions? SIP SS7 / SIGTRAN MGC Nc BICC-CS2 SIP-T Mc H.248 RTP IuCS GSM-A MGW Nb - RTP PSTN Figure 8: Nexus8610 – testing MGW – MGC This test setup allows the following to be tested: The correctness of the implementations of all interfaces and applications of the MGC-MGW under varying load conditions. The circuit switched (CS) interworking of the userplane on various interfaces such as AAL2 channels (e.g. IuCS), RTP sessions and 64kbps bearer channels (TDM). Conversion of encoded payload Any functionality implemented in the media gateway Nexus8610 Page 14 Nexus8610 and in the media gateway controller. Speech Quality Analysis on all simulated user-plane interfaces Verification of the correctness of voice prompts sent by the SUT. QoS Parameter verification on RTP and SIP Various types of data calls (transparent, nontransparent) with different sampling rates 64 / 56 kbps, 32 kbps etc. While test execution, Nexus8610 provides audio access to the payload channels. The user therefore can directly listen into any call. With the optional application Test Automation, testing can be performed 24x7, enabling an optimized utilization of the test tool. End-to End testing of a Converged Network in a test lab environment with Nexus8610 With its variety of supported interfaces and the wide range of protocols from Analogue, ISDN, CAS, SS7, VoIP, GSM, GPRS and UMTS, the Nexus8610 is the most versatile test tool to perform interworking and Endto-End tests as shown in Test issues Does the network correctly manage technologies that need to interwork? different How is the behavior of the entire network under varying load conditions on all its interfaces? Do the protection conditions correctly? mechanism mange overload Is the Speech Quality of individual connections depending on varying load conditions? Nexus8610 Page 15 Nexus8610 SIP SS7 / SIGTRAN MGC Nc BICC-CS2 SIP-T Nc BICC-CS2 SIP-T Mc H.248 MGC Mc H.248 RTP IuCS GSM-A PSTN MGW RTP PSTN IP backbone Nb RTP Nb RTP Figure 9: Nexus8610 – End-to-End testing in lab environment This test setup allows the following to be tested: The correctness of the implementations of all interfaces and applications of the under any load conditions. The circuit switched (CS) and packet switched (PS) interworking of the user-plane on various interfaces such as AAL2 channels (e.g. IuCS), RTP sessions and 64kbps bearer channels. Conversion of encoded payload Any functionality implemented in the network elements Speech Quality Analysis on all simulated user-plane interfaces Verification of the correctness of announcements sent by the SUT on all simulated interfaces. QoS Parameter verification on RTP and SIP Various types of data calls (transparent, nontransparent) with different sampling rates such as 64 kbps / 56 kbps, 32kbps etc. While test execution, Nexus8610 provides audio access; the user therefore can directly listen into any call. With the optional application Test Automation, testing can be performed 24x7, enabling an optimized utilization of the test tool. Nexus8610 SIP SS7 / SIGTRAN Page 16 MGW GSM-A IuCS Nexus8610 Technical Specifications Protocols Nexus8610 supports the following protocols: • SIP / SDP • RTP / RTCP • H.248 / Megaco • MGCP • SS7 ISUP, TUP • ISDN PRA / BRI • BICC CS-1 • UNI 4.0 • B-ISUP • CAS • Analogue • GSM • GPRS • UMTS Please request the latest Protocol List of the Nexus8610 Traffic Simulation System for detailed information about protocol variants and specifications implemented. Codecs Nexus8610 supports the following codecs: • G.711 • G.723 • G.726 • G.729 • GSM-EFR • GSM-FR • WB-AMR • AMR Nexus8610 Page 17 Nexus8610 HW test modules • STM-1/OC-3 HTM with 2 optical STM-1 port(s), single mode or multi mode, G.957, G.707 • Ethernet 10/100BT / Gigabit Ethernet • E1 2.048 kbps – 1 signaling channel for 48/56/64 kbps, termination 75/120, G.711 A-/u law codec for bearer channels, line code AMI/HDB3 • T1 1544 kbps – 1 signaling channel for 48/56/64 kbps, termination 75/100, A/u law codec for bearer channels, line code AMI/B8ZS • ISDN BA So/To – 8 or 16 subscriber lines, A-/u law codec for bearer channels • ISDN BA Uk0 (2B1Q coding) – 8 or 16 subscriber lines. • POTS 16 subscriber lines, A-/u law codec for bearer channels, line termination 600 or 900, Signaling DTMF Decadic, Metering 50/60 Hz – 12/16 kHz, Loop - Ground start, Flashing, ab wire polarity detection. Optional HW modules • SLE Signaling Link Extension, extends the number of HDLC links of an E1 or T1 HW test module in steps of 8 links. • DFB Digital Filter Board, performs accurate measurements of levels and frequencies of tones received in bearer channels or used for MFC signaling. DFB can be put to all Nexus8610HW test modules, except Ethernet (10/100BT) and STM-1. Per DFB up to 30 bearer channels (Analogue or 64kbps) can simultaneously be measured Nexus8610 Page 18 Nexus8610 Performance All figures are as per HW test module • SIP / SDP up to 250 simultaneous SIP sessions up to 400’00 BHCA (signaling only) • RTP / RTCP up to 60 simultaneous RTP sessions one Speech Quality Analysis of a connection at the time. • STM-1/OC3 up to 2000 subscribers per STM-1 for user and control -plane simulation. up to 20’000 subscribers for controlplane simulation (signaling only). • H.248/MEGACO up to 700’000 message transactions / hour. • MGCP up to 700’000 message transactions / hour. • GSM-A up to 24'000 BHCA with speech path verification (call duration 1 sec) • SS7 ISUP up to 380,000 BHCA (8 HDLC links) without speech path verification. up to 20,000 BHCA with speech path verification (call duration 1 sec). • ISDN PRA Up to 160,000 BHCA without speech path verification. up to 13,000 BHCA with speech path verification (call duration 1 sec). • ISDN BA up to 135,000 BHCA without speech path verification. up to 11,500 BHCA with speech path verification (call duration 1 sec). • Analogue POTS up to 8,000 BHCA with speech path verification (call duration 1 sec). Nexus8610 Page 19 Nexus8610 Abbreviations CAS Channel Associated Signaling CS Circuit Switched GPRS General Packet Radio Service GSM Global System for Mobile communications ISDN Integrated Services Digital Network MGC Media Gateway Controller MGW Media Gateway MOS Mean Opinion Score OPTEC Optimized Testcase Composer PAMS Perceptual Analysis Measurement System PDN Public Data Network PESQ Perceptual Evaluation of Speech Quality PLMN Public Land Mobile Network POTS Plain Old Telephone Service PS Packet Switched PSQM Perceptual Speech Quality Measure PSTN Public Switched Telephone Network QoS Quality of Service SS7 Signaling System #7 SUT System Under Test UMTS Universal Mobile Telecommunications System TCU Test Control Unit Nexus8610 Page 20 Nexus8610 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 3.0 Date May 2005 Author Franz Neeser All General Inquiries: [email protected] Nexus Telecom AG System Solutions Feldbachstrasse 80 P.O. Box 215 CH-8634 Hombrechtikon Switzerland Nexus8610 Tel. +41 55 254 5111 Fax +41 55 254 5112 [email protected] [email protected] Nexus Telecom AG Wireless Network Systems Muertschenstrasse 27 P.O. Box 1413 CH-8048 Zurich Switzerland Tel. +41 44 355 6611 Fax +41 44 355 6612 [email protected] [email protected] Page 21 Nexus Telecom (Americas) Inc. (NA and CALA) Suite 100 1101 Prince of Wales Drive Ottawa, Ontario Canada K2C 3W7 Tel. +1 613 224 2637 Fax +1 613 224 2761 [email protected] [email protected]