Performing a Network Assessment involves a few steps to insure that network problems are easily identified and resolved. The following procedure is recommended:
- Deploy PathSolutions software in the environment to be assessed. Follow the license instructions to download and install the software. At the end of the installation, the Quick Config Wizard will run and will set up the license and scan the network looking for devices to monitor.
a. It is strongly suggested that the error rate threshold be set to 5% in the Configuration Tool to insure that interfaces anywhere in the network that have errors are caught. When the wizard is finished, it will present you with the Device List.
b. After installing the solution, verify that all involved switches, routers, servers, and gateways are monitored. If the deployment is not monitoring all of the devices in the environment, then the assessment may provide incomplete or inaccurate results and you may be blind to any issues that may be occurring in your Network.
c. Let the solution monitor the network for 24 hours. Problems that occur in the environment during that period will be identified.
- Review the Assessment Report: View the “Assessment” tab and click on the “Download Assessment Report” link in the upper right corner to view the assessment of the network in its current condition. This report will disclose the inventory of devices on the network, OS versions, MOS scores, Issues, half-duplex interfaces, and 10meg interfaces in the network.
Review each section of the Assessment Report:
a. Insure that the inventory of identified network devices are capable of handling VoIP traffic. Issues should be evaluated to determine if they would affect VoIP, and/or get them resolved.
b. The Half-duplex and 10meg interfaces should be eliminated.
c. Insure that WAN bandwidth is adequate for both data and VoIP needs
d. Insure that QoS settings on WAN links are properly configured.
e. Equipment identified with out-dated OS’s or older equipment that does not support VoIP should be upgraded.
f. MOS scores that are poor should be investigated (determine if the cause is due to loss, latency, or jitter).
g. Remedy diagnosed problems in section IV “Work to be done”.
- Simulate VoIP Calls: Once the identified problems have been resolved and verified via the assessment report, simulated calls should be produced to further validate that the network can handle VoIP traffic at expected volumes. The Call Simulator is located on the “Tools” tab under the “VoIP Tools” sub-tab. The Call Simulator can be run from any computer in the networked environment. Tests should be performed from site to site across the WAN to validate different segments of the network. The simulated phone calls can be run for up to 24 hours. The results of each test should be saved for future dissemination & diagnosis. If any call quality problems are identified, the results should be correlated with network conditions.
- Power Over Ethernet review – Evaluate the PoE powered switches (Device tab, PoE tab) to make sure they have enough power for the deployment.
- Spanning Tree Protocol review – Evaluate the STP environment (Device tab, STP tab) to make sure that the topology is stable (“Last Change” field is at least a week old), and the Root Bridge is the correct device for that broadcast domain.
Call simulations should be run across WAN links to test for QoS
a. Run one call simulator across the WAN link with QoS enabled
b. Run a second call simulator across the WAN link with QoS disabled, and set for the codec “Bulk Data”.
This will simulate an FTP transfer. During the testing, the QoS enabled simulation should not show any degradation during the bulk data testing. If problems are detected, QoS configurations should be investigated.
- Utilize the Assessment report and monitor the Issues tab for network faults and anomalies that may crop up as a result of the new load that VoIP is adding to the network. Resolve identified problems as they become apparent.
Note: In certain cases, a longer-term assessment period is warranted to avoid lengthy troubleshooting of VoIP problems that may occur post deployment.
With all of the above covered, you should end up with a very stable VoIP environment.