What multicast addresses are used by Livewire

Updated 2 months ago by Bryan Jones

Scope

Livewire operates using a standard set of multcast addresses. The Livewire channels are simply an alias to a real multicast address. This document defines what addresses are used by Livewire so that if you are doing other, non-Livewire multicast (like AES67 or SMPTE2110) you can stay clear of these addresses.


Technical details

Livewire was made simple by using the channel number as an "alias" for the real IPv4 multicast address. It's important to know these addresses so that you can keep clear of these ranges when doing other multicast on the same network. A real-world example of this would be using Dante devices in AES67 mode in conjunction with your Livewire devices. It's critical to keep all multicast unique.

Address assignments from within this range are specified in RFC 5771. The entire multicast range is from 224.0.0.0 to 239.255.255.255.

Livewire uses the "Administratively Scoped" range of addresses as further defined in RFC 2365. These addresses are thought to be for private use by an organization. These are locally assigned and are not required to be globally unique. Administratively scoped addresses are in the range of 239.0.0.0 to 239.255.255.255


Specific Livewire addresses

The entire Livewire spec includes many more ranges than were ever implemented (or have yet to be implemented). In a practical sense, the ranges you need to stay clear of today, are;

  • 239.192.255.1 - Livewire high rate clock
  • 239.192.255.2 - Livewire slow rate clock (used for Standard Stereo streams only)
  • 239.192.255.3 - Livewire advertisement and source allocation
  • 239.192.255.4 - Livewire GPIO
  • 239.192.0.0 to 239.192.127.255 - Livewire audio channel 0 to 32767
  • 239.193.0.0. to 239.193.127.255 - Livewire backfeed audio for channels 0 to 32767
As mentioned, Livewire channel numbers are simply an alias to a multicast address. For example;
Channel 1 is 239.192.0.1
Channel 255 is 239.192.0.255
Channel 256 is 239.192.1.0
The automatic backfeed for Channel 1 would be 239.193.0.1 (note that it's 193, not 192)
For a document on how to calculate addresses and Livewire channels, check out this document


Is it safe to use Livewire multicast ranges for other things?

Yes; however, it's important to be able to keep them straight. AES67 and SMPTE2110 multicast will not "advertise." This means that you could have a Livewire device using channel 12345 (that's the multicast address 239.192.48.57) and also configure a Dante device using the same multicast address. This would create a duplicate address on your network and cause audio problems. While you CAN use these Livewire ranges, you probably should try to keep them separate.


More info

We have a number of other documents covering the topics of multicast. Some are more general. Some are specific to a particular product. You can search our support site for the term multicast, or click this link.


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