Ready for VoIP: Network Management Architectures: JDSU
An industry heavyweight—formed from mergers of other heavyweights—JDSU's equipment is robust enough to test any communications network.
JDSU's Communications Test and Measurement business provides the instruments, systems, software, and services that enable IP/broadband communications from the headend to the home, with an established presence worldwide supporting deployments of VoIP, IPTV, and a variety of triple- and quad-play service offerings, big and small, ensuring reliability, efficiency and lowering operational costs.
JDSU's Communication Test and Measurement business is built on its acquisition of Acterna, which led several communications test markets in consecutive years and was home of the industry-standard T-BERD optical network test system. Acterna, in turn, was formed when Telecommunication Techniques Corporation (TTC)-then the world's third largest communications test and measurement company-merged with Wavetek Wandel Golterman, then the world's second largest test and measurement company.
JDSU has continued to market the Acterna line of stand-alone protocol analyzers, which are named the DA-3400 and DA-360A products.
The DA-3400 system supports a number of network topologies, including 10/100/1000 Ethernet, WAN, ATM, Mobile, and VoIP, with the capacity for multiple interfaces within the unit. The DA-3600A system supports speeds from 56 Kbps to 2.4 Gbps, including WAN analysis up to the DS-3 rate, and real-time VoIP and VoATM call quality analysis.
The systems have the ability to decode over 450 different protocols and to identity over 1,000 more. VoIP protocols supported include RTP, RTCP, SIP, H.323, SCCP, MEGACO/H.248, MGCP, and SIGTRAN. Both units have available a specific VoIP Analysis Option, which enables the DA-3400 to perform real-time analysis of 8,000 simultaneous calls, the DA-3600A 64,000 simultaneous calls. These large capacities are the result of custom hardware implementations that ensure that all call statistics and quality measurements are accurate, regardless of the network utilization or the presence of non-VoIP traffic.
The systems include the abilities to provide standard Mean Opinion Score (MOS) and R-factor calculations for both directions of every call, with sorting, filtering, and display customization that can focus on specific areas of concern.
Each call is also monitored for packet transport quality. The systems generate 'expert events' when defined thresholds are exceeded and sends Simple Network Management Protocol (SNMP) and e-mail alerts to the administrators when the call quality falls below pre-configured thresholds.
The complex call signaling messages can be illustrated graphically-including the timing and response codes during call setup and call disconnect procedures-with a multi-station display that can illustrate all the connections for a conference bridge. Another interesting feature is the extensive display filtering of the VoIP calls, which allow a subset of the calls to be analyzed. For example, if poor quality calls occur on only one specific subnet, those calls can be viewed based upon a specific phone number, or unique VLAN or MPLS label.
A second product line, the PVA-1000 Analysis Software, is a system that runs on Windows 2000, XP, and Vista PCs to support VoIP network implementations. The PVA-1000 performs full analysis of VoIP calls with jitter, packet loss, and audio playback test capabilities for enterprises, call centers, and carriers delivering service in VoIP, IMS, and fixed-mobile converged environments. It is compatible with a variety of network service and infrastructure types, including softphones, wireless IMS networks, wireline networks, VPN, and enterprise.
The software can identify individual calls and evaluate their quality (Figure 1), and provides jitter (Figure 2) and packet loss (Figure 3) graphs that show the distribution of impairments throughout the call. It can also display call signaling trace diagrams to illustrate the details of the message exchange timing and result codes (Figure 4).
Among its strongest features, the PVA-1000's new Capture Agent lets the system monitor multiple calls and generate individual packet capture files for each call that falls below a predetermined MOS threshold, automatically transferring the resulting capture file to a pre-selected server. These Capture Agents can be placed on Ethernet Switch SPAN ports, PCs with softphones, or desktop PCs connected to IP phones, making them ideal for network turn-up, acceptance, and troubleshooting applications.
In addition, the PVA-1000 can perform signaling trace, audio playback, and full decodes of signaling and media packets, improving the ability of operators to quickly and proactively troubleshoot common errors in VoIP performance such as delay and echo.
Further details on the JDSU architecture and products can be found at www.jdsu.com. Our next tutorial will continue our examination of vendors' network management architectures.
Mark A. Miller, P.E., is President of DigiNet Corporation, a Denver-based consulting engineering firm. He is the author of many books on networking technologies, including Voice over IP Technologies, and Internet Technologies Handbook, both published by John Wiley & Sons.
Article courtesy of Enterprise VoIP Planet, © 2008 DigiNet Corporation, All Rights Reserved