Hand it Over, Internet

WheatTie CLOUDS_2560If you’re thinking about handing over program distribution to the public internet, Brian Kerkan of Crawford Broadcasting has some advice for you.

Do yourself a favor and oversubscribe on bandwidth if you’re not able to set up a guaranteed QoS network, he says. His group in Detroit is paying around $100 a month for 20 megabits/second upstream. That’s easily four times the bandwidth needed for sending audio programming over the internet. “It’s overkill but whenever there’s congestion we have enough actually subscribed in the network to make up for any network issues, and everything has been fine,” he comments.

Brian also suggests using SNMP to get in front of any packet problems you might have, and to use a good codec; he’s using the new Opus. Oh, and to grow a backbone – you’re going to need it.

“Was a I nervous about using the Internet? Oh, yes,” relates Brian, who is the engineer for Crawford’s WMUZ-FM, WEXL-AM and WRDT-AM in Detroit where the Bob Dutko show is syndicated. “Not too many are doing this because they’re afraid of doing it. I mean, there’s a lot of risk when you put your traffic out on a network that’s not guaranteed. But the internet has become so much better that it’s worth it, and besides, Cris Alexander (Crawford’s Director of Engineering) had tested a similar system in Denver prior to our deployment here in Detroit.”

Plus, he adds, the old way of getting Crawford’s Bob Dutko show across country from Detroit to Albany and Portland isn’t getting any easier. Satellite delivery is becoming obsolete, he says, and vendors aren’t supporting the equipment anymore. It helps, too, that internet delivery is at least a third the cost of satellite.

Crawford Broadcasting started with a test feed at the beginning of the year. For a period of time they ran distribution in parallel on both satellite and the internet to fully evaluate the system prior to the cut over from the CBC satellite up/downlink to internet program distribution using the Tieline Genie, which is available with WheatNet-IP inside.

The Bob Dutko show is originated in the Detroit Wheatstone studio. Programming is fed directly from the audio network into the Genie distribution system and sent across – or more like bounced around – the public circuits, finally arriving in Albany, Portland and other syndicated markets.

Short of running a costly VPN, or setting up a RSVP drop or other guaranteed QoS network between locations, Kerkan says there’s plenty a broadcaster can do to circumvent some of the packet issues and congestion typical of the circuit-switched public network.

There are settings on the Genie that allow him to differentiate traffic for better QoS, for example by tagging audio bits for priority delivery or setting priority status by port.

And there is the bandwidth overkill mentioned earlier, now that bandwidth is cheap compared to satellite distribution costs. The Opus bit-reduced talk programming runs well within the 20 mbps stream subscribed, so programming is all but ensured to get through with few errors. “As long as the jitter buffering (in the Genie) has enough information in it, you have some degree of error correction within that (20 megs) window,” he explains.

Because the program is pushed live with no interaction between each end of the feed, there’s no issue with delay. In any case, Internet delay is considerably less than satellite delay.

Brian is using the Wheatstone Scheduler software to make and break the connections on the Genie, so that when the time comes, the show is automatically shuttled across the country. With four mics open on the show at all times, he recently added an M4-IP mic processor to the audio network, the controls and presets of which the talent will be able to access from afar.

SNMP used in the network gives Brian a great deal of information on packet loss and traffic stats, and so far, so good, he says.

Editor’s note: Genie with WheatNet-IP inside is an all-inclusive distribution codec unit that interfaces with the WheatNet-IP environment and distributes over the internet or other external IP network up to 3 stereo (6 mono) audio channels between WheatNet-IP studios. Inside the Genie distribution unit is a WheatNet-IP audio card that’s compatible with the AES67 standard for AoIP interoperability. The rear panel of the Genie provides a WheatNet-IP LAN interface for connecting directly into the WheatNet-IP network.

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