Computers on an Axia Livewire can send and receive audio to/from other Livewire-enabled hardware via the Axia IP Audio Driver. This is fairly easy to setup. However, it is not obvious how to setup backfeeds within the setup utility.

Thankfully it is possible, albeit with a little messing around.

Why would you want to have a backfeed on a PC? Typically an audio playout computer wouldn’t need a backfeed. The most obvious reason I can think of is to run VoIP applications such as Skype.

Step 1: Find the Multicast IP Address

All Axia audio is transported around your LAN as multicast packets. Each “stream” gets it’s own Multicast IP Address, in the format 239.192.XXX.YYY (regular streams) or 239.193.XXX.YYY (backfeed streams). You can see here that backfeed streams are differentiated by the number in the second octet (192 and 193).

To work out which stream IP Address you need, you can either do the maths or use the SDP generator to work it out for you. Fill in your stream number, and then look for the line “c=IN IP4 239.192.0.101“. This IP address is what you are after.

Step 2: Telnet into your IP Driver

The configuration of the IP driver needs to be done via TCP connection (Telnet is the easiest way to connect). Windows 7 and upwards doesn’t have a built-in Telnet client, so you can try PuTTY. Mac OS X still has one built-in.

Open a connection to 127.0.0.1, port 93 and then run these commands:

DST 2 ADDR:”239.193.XXX.YYY”
SAVE

Substitute “2” for the destination channel on your driver, and XXX.YYY for the IP address you found in step 1.

After running these commands you should now be able to stream a backfeed in via your Axia IP Driver.