If you’re getting ready to jump into AoIP networking – whether it’s building a whole new physical plant, retrofitting existing studios or constructing a distribution network for otherwise analog facilities – there is one thing you can do to simplify your life immensely: forget what you know about wiring an analog facility.
Many engineers, when they first begin planning a networked installation, still think in Analog mode. What I mean is, they develop the wiring plan for their IP-networked plant while still thinking in terms of discrete audio pairs, home runs, and centralized switching. We’ve actually seen new studios, with IP-Audio routing, wired the old-fashioned way – using punch blocks and shielded-pair cable to feed signals to a central core switch.
This actually negates one of networking’s biggest advantages: the de-centralization of audio routing. In the old days, the “big iron” resided in your TOC. If you wanted to send audio from one studio to another, you had to run cables from the local studio to the rack room, where it was switched back along another set of cables to the place you wanted it to be.
But with AoIP audio, the network is the router. That is, the data routing capabilities built into the network’s Ethernet switches take the place of the centralized routing switcher. Instead of sending audio back to a central core, adapters that convert audio signals to Ethernet data are placed at the edges of the network, close to the devices that supply that audio. The network is then configured in a star-of-stars or ring topology, or uses Spanning Tree Protocol to ensure complete audio data redundancy.
As a result, you can eliminate somewhere around two-thirds of the cost that discrete cabling added to your build, replacing all that multi-pair with CAT-5 and CAT-6 runs. A single 100Base-T link can carry as much audio as a 100-pair cable – accompanied by machine control logic as well.
So, by forgetting some of those analog habits, you save time and money in installation, eliminate the tedium of circuit documentation, and kiss goodbye the rat's nest of barrier strips and punch blocks in your comm room. And those are some memories we can all feel good about losing.