A SMPTE ST 2110-networked environment must deliver all of the benefits of an IP infrastructure – with the predictability of SDI – in order for it to be useful. This challenge can be met only when the infrastructure is well-managed and edge devices respect specifications. A rogue ST 2110 device may not deliver as expected, which would be bad enough. More importantly, it could adversely affect other functioning devices and lead to unpredictable general failure, which could be catastrophic.
With this in mind, the first step to take after acquiring a new ST 2110 device for a broadcast network is to make sure that it is a good “network citizen.” A good network citizen will not affect the network or disrupt operations when it is directly connected to an on-air production environment. The second step is to actually test the promised functionality and its compliance to SMPTE standards and industry norms. For example, a production environment that is architected around ST 2022-7 redundancy would be very poorly-served if devices do not actually support the ST 2022-7 specification properly – which could ultimately lead to disruptions.
It is important to understand that some devices might actually work well in a small synthetic setup, but fail when put into a real working environment. Due to a number of unaccounted variables, a simple pass-fail test may not be sufficient to make informed decisions on choice of equipment. For example, network packet timing is very different when several transmitters are sending to one receiver compared to a single transmitter sending to a receiver. The timing of a sender is also different if it sends a single ST 2110 flow vs. several flows. Another typical testing pitfall is the dependence on one kind of transmitter. A receiver might work great with a narrow gapped transmitter – like an SDIto-IP gateway – but not work well with a wide linear transmitter.
At first glance, issues like these may not appear to be a problem if the environment may only contain narrow gapped devices. However, knowing the functional boundaries of a working environment is critical to maintaining future expansion. Misinformed decisions taken today may limit future capability and possibilities, (e.g. supporting wide senders). To pre-empt this, it is advisable to build up a test suite that pushes the test boundaries for imperfect, but sufficiently good cases. It is only with these types of tests that informed decisions could be made, eventually leading to judicious ST 2110 device purchases, safe device firmware/software updates, and beneficial service agreements.
