AoIP Testing & Troubleshooting

AoIP Testing & Troubleshooting

PaulPicardBy Paul Picard, Wheatstone Systems Engineer

In the analog days, you could easily track down most problems with just a pair of headphones and some clip leads.

 

While you will not be able to signal trace your AoIP network the same way, a different set of procedures and tools does allow you to probe and poke the infrastructure to eliminate network segments and devices. The testing methods and tools are different, but the old divide and conquer approach still applies.

There are three levels of testing in the professional data communications cable installation world: verification, qualification, and certification. Each level provides a higher degree of parameter testing. At Wheatstone, we use some combination of these test methods and tools to commission and install WheatNet-IP AoIP systems in order to get the job done quickly and correctly.

Verification testing is essential for pre-testing all wall outlets, patch cables, and horizontal runs between patch panels and equipment racks. The goal is to verify that basic wire maps are correct. Other tests may include checking for shorts, opens and correct wire length. An integral tone generator is useful in tracing lost cables a la the "fox and hound" method. This type of tester is used for routine testing during the initial termination phase of the build-out but by no means should this be the end of testing for plant wiring. Remember, the network you are building is the backbone of the entire IP audio system, which is why we like to move on to qualification testing once we've verified the above is working correctly.

Qualification testing is a relatively new class of testing brought on by the availability of an innovative series of lower-cost but powerful test tools. Qualification can be used on new or existing installations to see if certain classes or types of services will run on the installed cabling and Ethernet switches. Qualification analyzers bring testing for bandwidth, port configuration cable faults, cable length and wiremap together but do not run the full series of crosstalk tests as is done in certification testing. Qualification testers can be purchased for about $1,000.

Certification testing guarantees that the cabling system is in compliance with the TIA/EIA 568x and other industry standards. Any broadcast engineer who installs an Ethernet audio network should plan on certifying the network infrastructure prior to bringing the hardware online. Certification testing erases a huge unknown: Does the network I just installed meet the 1000BaseT specifications? You simply don't know until it is certified. We work with several professional organizations that certify networks, and we highly recommend that broadcasters get their infrastructure certified before running audio through the network.

For further information and a lot more detail on these topics, read my full white paper on the subject, available via this link on the Wheatstone web site: 

pdf The Role of Wiring Integrity on AoIP Network Reliability

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