When shopping for a switch, the two most important things to find amid all of the acronyms on the spec sheet are "IGMP Snooping" and "IGMP Querier." If after reading the data sheet you're still not sure that the features are supported, find the manual for that model online and look up how to set up both features. If it's in the manual, the feature had better be there.
A capable switch for an AoIP system can range in cost anywhere from $600 to over $1,000. Not every switch will be recommended by every AoIP manufacturer and not every switch will be the right tool for the job.
Start with a plan
Map out the network infrastructure before you make a purchase. The first thing to take into account is whether or not you already have suitable Ethernet cable in the walls and/or where you have available conduit or cable trays in place to get to the studios. The second thing to take into account is that unlike a network switch that you can buy at the office supply store, a switch capable of handling AoIP will have to crunch a lot of numbers, generate a lot of heat, and have a small noisy fan inside to keep itself happy. Therefore, while the AoIP appliances are fanless and suitable to mount inside a studio, the network switch is not and should be mounted in a rack somewhere else.
Most radio stations have set up their IT infrastructure with all cable runs terminating in an equipment rack locked away in engineering. This is ideal for AoIP: It's simply a matter of making room in the rack for your AoIP network switch and connecting the studio runs to the switch.
Some facilities may elect to use multiple switches due to the layout of the building or available conduit. In this event, set up the querier switch as the core of the network and have snooping capable switches on the edges talk to the querier at the core.
Which model do I buy?
Like most computer equipment, the moment that this goes to press, any model numbers listed would be already out of date.
Generally speaking, the top end of Netgear's professional series represents the entry level in IGMP capable switches. HP's ProCurve series is the midrange tier, and Cisco represents the high end.
The support department will be able to recommend a current switch that fits a station's needs and budget.
Davis works in tech support for Logitek Electronic Systems, Houston.