Joined: 25 May 2007
Location: San Luis Obispo, CA
An Axia node is an i/o device to the IP world of audio routing. The node, being it an Analog node, a Digital node, or Microphone node does the same thing. It takes audio and converts the audio into a 48Khz - 24bit audio stream and delivers this data to a multicast group. Each node has 8 inputs and thus has the ability to deliver this audio to a multicast address. Which Multicast address? Based on the channel number (Livewire Channel Number) that is entered into the Sources page of a node, the Node will create a Multicast address. For example,
if the number 1 is entered, the multicast address will equal 18.104.22.168 (this is where the 48KHz-24bit stream goes)
if the number 100 is entered, the multicast address will equal 22.214.171.124
if the number 256 is entered, the multicast address will equal 126.96.36.199
if the number 1101 is entered, the multicast address will equal 188.8.131.52
typically, you do not need to concern yourself with these Multicast address numbers, all you need to concern yourself with is the number that is entered into the Channel field. As long as each channel field is given a unique number, you will not have duplicate multicast streams.
So the question that comes up is how does one best maintain the system to insure that no device will create a duplication of Multicast data.
In the day of analog facilities, a well built plant would have each cable numbered. The number of cables was astronomical. A good practice of the time was to create a wire book. This book was a list of each wire, its number, and what was connected to each end of the wire. The amount of information could be very extensive depending on how complicated the wire job was. The same practice could be applied to the Livewire-Axia domain, and the end result again is a massive book that one must refer to any time they wish to make a change or find something. I personally believe this is a poor practice and better options are available today with the Axia-Livewire system. For example...
Each device connected to the network requires an IP address. Depending on the Class of network, the amount of available network devices can vary - for simplicity, I will discuss a class-C network. A vanilla flavor Class-C provides 254 unique addresses. This is plenty. If we imagine a facility with 6 physical studios, we can divide the available quantity of unique addresses into 6 or more groups. I also believe that their is room to divide this into logical, easy to remember groups. For example,
Studio 1 is given IP addresses X.Y.Z.110 - X.Y.Z.119
Studio 2 is given IP addresses X.Y.Z.120 - 129
Studio 3 is given ip addresses X.Y.Z.130 - 139
So you can see that the last octet of the IP address will define its location. 110-119 = Studio 1 and 160-169 = Studio 6. This equates to 10 devices per studio. This is plenty for any studio.
Now providing a unique IP address to every device in your network is fairly easy and spelled out above. Now we need to address Livewire Channel numbers. Again, each Livewire Channel source needs to be given a unique "identifier" (Livewire Channel Number). Livewire Channel Numbers can be anything from the number 1 to the number 32767. So how should one organize this? Use the methods of wire books or use a logical numbering method? I've explained how one might design an IP numbering plan, why can't we spawn off of that same design? For example,
St1_Analog-Node = X.Y.Z.111
Input.1 = 11101
Input.2 = 11102
Input.3 = 11103
Input.8 = 11108
As can be observed, the first three numbers of the Channel have a relation to the last octet of the IP address of the device. If we consider the possibility that we would never introduce two devices with the same IP address, we could conclude that no Livewire Channel numbers would be the same.
Device A (X.Y.Z.121) Ch#12101-12108
Device B (X.Y.Z.122) Ch#12201-12208
This is a typical method in which I personally would number a facility.
Random numbering of Sources provides almost no protection against duplicate Multicast data streams.
Creating a sequential numbering plan leads to the need of the "wire book" and the perpetual need to always reference to the book for what has been used and what hasn't been used.
Creating a logical number plan which referenced to previously established numbers can help isolate the possibilities of duplicate numbers and also leads to a better organized system that can easily be maintained.
I hope this information is helpful to you and if you have any questions in any manner related to Axia or Livewire, feel free to ask us and one of our fine Technical staff members will assist you.