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As more companies switch over to VoIP solutions as their primary means of voice communication, data network testing options are becoming increasingly popular. NetIQ created Chariot VoIP Assessor
as a tool for a company�s IT department or a Systems Integrator to help determine whether or not a network is capable of handling specific types of VoIP traffic. TMC Labs acquired the software for the Chariot VoIP Assessor from NetIQ, installed it, and then assessed our own WAN and LAN using the product.
INSTALLATION
Running this product requires two separate applications: the administration software and the endpoint software. The endpoint software is free, and so is the evaluation version of the administration software for that matter, with imposed limitations of course. In any event, the endpoint software can be loaded from
NetIQ's site directly to machines running Windows 98, Me, NT, 2000, and XP in addition to various SUN and Linux platforms. When installing endpoints, the administrator may want to consider typical voice traffic within the company, and use this model as a prototype for conceptualizing how to route VoIP traffic. To accurately assess the network, you�ll need to install at least one endpoint in each area of the WAN; NetIQ defines them as Call Groups. The documentation does a wonderful job of both articulating and illustrating this point. The endpoint software doesn�t save any files or write anything to the computer�s registry. It runs as a service, and if a company chooses
not to buy the software to test its own network, it�s very simple to uninstall.
Installing the administration product wasn�t really any more difficult than installing a typical end-user software program. Insert the CD, follow the wizard, and you�re pretty much finished. The PC running the software must be a least a Pentium with a minimum of 64 MB of RAM (128 is recommended), 150 MB of free disk space, and I.E. 5.0 is also required. Additionally, Microsoft Word 97 and Excel 97 (or higher) are required to generate the reports. The software runs on the 98, Me, NT 4.0 (with Service Pack 3.0 or higher), 2000, and XP operating systems.
OPERATIONAL TESTING
Design An Assessment
After installing the software, some tweaking is necessary to customize the assessor for a particular network. Planning the assessment is the largest consideration before actually moving forward with the logistics. For example, our company CTO is at our branch office, while his support staff is at the corporate headquarters. Because we�re utilizing a leased line to connect both offices, this will be a key avenue to test, given that it�s a high traffic area. Once some thought is given as to how an assessment should be performed to render itself effective, endpoints must be chosen.
Endpoints are nothing more than several PCs chosen in respect to their physical location, which are running
NetIQ's endpoint software. We chose five computers for our endpoints, including the 2000 machine running the Chariot VoIP Assessor software. NetIQ advises that installing the software on the computer performing the assessment is fine for becoming familiar with the program, however does not recommend including the machine in the network assessment. Taking that advice, we moved to the Design portion of the GUI.
NetIQ has fashioned a super-simple GUI that makes the program very easy to configure. Assign the computer a name, type in its IP address, and you�re done. Though assigning each endpoint�s addressing information manually isn�t a problem for an administrator, it would have been nice if the Chariot VoIP Assessor detected each PC running the endpoint software on the network and plugged in the respective IP address, so we didn�t have to. After all the endpoints have been defined, Chariot VoIP Assessor requires designing the call flow. Using the VoIP Connector tool, simply draw a line using the pen-shaped pointer. In choosing a connection, some parameters need to be defined in addition to the choice of linking two PCs. A call script must be chosen (the program defaults to the G.711u codec call script however, the administrator can choose between G.711a, G.723.1 ACELP, G.723.1
MPMLQ, G.726, and G.729 depending upon what codecs a prospective solution may be using. Those choices will probably suffice for many applications, however, since the call scripts loaded with the program are read only, Chariot VoIP Assessor gives you the option to redefine a codec if the default options don�t have some of the same measurements you require, such as enough jitter buffer, additional fixed delay, silence suppression or PLC (Packet Loss Concealment). For our testing purposes, the stock call scripts were fine, but it�s nice to know those features are available if you should require them. We used a few different codecs on the same call path by connecting the same PCs several times with varying parameters.
Run An Assessment
Before running an actual assessment of the network, NetIQ provides a tool within their program to test the design of your configuration � helping to ensure that an eight-hour test assessment will work, and not take an administrator eight hours to run it, only to deem it a failure. The verification process actually contacts each of the endpoints and sends them the call scripts. NetIQ refers to verification as a �mini-assessment� informing you
up front whether or not changes need to be made to the configuration before running a much more extensive assessment. An error log can be viewed to help make corrections; our verification went well.
The Schedule tool is used to begin an assessment requiring the days or hours to run the test, the duration of each call and the interval between each call. Our test (we ran several shorter tests before this one) was scheduled for eight hours, with calls lasting for two minutes at 15-minute intervals. After this information is input, the assessment can be started at any time. We thought this feature could have been expanded upon somewhat to include some sort of automated scheduling. This we thought would allow administrators to schedule assessments during third shift or on a weekend for example, when they are either out of the office, or perhaps on holiday.
Generate A Report
Reports were far and away the best we�ve seen in a long time. By provisioning some very granular information in the Complete report, it was very professional and seemingly ideal for a systems integrator. Requiring Word and Excel to install the program, VoIP Assessor uses Excel to create charts and graphs based on the assessment results, and imports them into a Word template, which
includes both a table of contents and appendices. The report scores call quality and parses attenuation such as packet-loss, jitter, and delay; and
then displays the results for all of the Call Groups (overall results for the network), by the day, by the hour, and by the script to name a few. Additionally, the report then breaks down the network and parses the data to provide an assessment for each VoIP connection,
i.e,. endpoint-to-endpoint. Our eight-hour assessment generated a 60-plus-page report.
CONCLUSION
Based on the assessment we ran with the specified VoIP traffic simulation, our network was deemed favorable for a VoIP solution using the G.711u and G.723.1-MPMLQ codecs on our LAN and WAN. NetIQ considers delay, jitter, and lost data when calculating their MOS (Mean Opinion Score) estimates, therefore altering slightly the ITU G.107 standard. Each of our call groups scored from 4.38 to 4.36 when assessing the
network's capacity to handle the G.711u simulated traffic, and 3.81 when assessing the G.723.1-MPMLQ traffic. In the most general assessment of our network, the quality degradation was said to be mainly from the Codec Delay (67 percent), followed by (network) Delay (28 percent), with the remainder of the pie chart attributing the balance of percent points to Jitter and Lost Data.
Overall, NetIQ�s Chariot VoIP Assessor appears to provide an option to investing in a VoIP solution and
hoping that it performs well on your network. It seems to be an easy-to-use and respectively inexpensive
alternative to assessing the quality of VoIP on your data network, before you invest in a solution. Its intuitive
and user-friendly GUI, excellent documentation, in-depth network information gathering, and
professional, thorough reports have earned it a TMC Lab�s Editors� Choice Award.
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