So some radio station is transporting audio over IP from studio to
tower. A few weeks ago they started getting skips in the audio, and
they're finger pointing at me. At first I couldn't even see a problem.
Eventually I find that every so often there's a 1/10th second event with
packet loss. Seven seconds after the event you hear a little blip on
the radio. You could go a few hours between events, or only a few minutes.
I said yeah I'll try to track down what's causing that, but if you have
a 7 second delay on this one-way transmission, isn't there plenty of
time to resend 1/10th second of missing audio?
*grumble grumble*, finger point, it worked before, etc
So I've been trying to narrow down where this is happening and swap
interfaces and such. And keep in mind anything I do interrupts the
radio so I have to do it at odd hours. Periodically during the process I
re-ask why does this even happen? This amount of loss shouldn't hurt you.
*grumble grumble*, finger point, it worked before, etc
So today they let me take a look at their Comrex audio streaming
thing-a-ma-bobbers, and I looked in the manual. Turns out the error
correction features don't work on lossless audio codecs unless your
firmware version is above a certain revision. Theirs isn't above that
revision, and they're using a lossless audio codec. So now I'm like,
yeah I'll keep looking for that little blip, but in the meantime you
don't have to hear it if you'll upgrade your firmware and enable FEC.
They've had a number of people looking at this, including their
engineer. Their equipment has robust enough error correction that they
could run that stuff on satellite or 4G if they wanted to. It's just not
configured right!
You'd have fixed this in half an hour if you'd have RTFM'd you frickin
noobs.
--
AF mailing list
AF@af.afmug.com
http://af.afmug.com/mailman/listinfo/af_af.afmug.com
