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Topic: Cobranet Bandwidth Calculation

Hi,

I'm working on a project with 30 NIONs and a lots of amplifiers, close to 300. I doing the study of the bandwidth usage and network (switchs) design.
I searched the web, the docs and I can't find a magic formula to calculate the bandwidth. I collected some data but I'm confused if that is good:
   - on 100 Mbps network you can use (max. recommended) 8 Bundles (64 channels of 48 kHz, 20 bits)
   - Aprox. 1 Bundle = 1.3 Mbps of network usage
   - No difference in Unicast and Multicast.

Another question is that N6 Spec Sheet says on "cobranet performarnce" paragraph that cobranet supports 32x32 channels at 48kHz:
   - that means that 32 input and 32 output ? any other combination ?
   - that means that cobranet rj45 is only 100 Mbps network ?

I hope someone can help me and I think that this info can be important for many people.

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Re: Cobranet Bandwidth Calculation

driera,

8 FULL Bundles (64 channels of 48 kHz, 20 bits) is the recommended maximum a 100BT link.

Your number on bandwidth consumed per bundle is incorrect.

Each CHANNEL at 48 kHz, 20 bits takes about 1 MBit so that would be 8 MBit per each full bundle, not 1.3 MBit
The bandwidth is the same for multicast and unicast but where the bandwidth is consumned changes.
Remember that for Unicast the bandwidth is used only on the links between the source and destination.
Multicast bundles consume bandwidth on every link in the network.

Nihilism is best done by professionals

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Re: Cobranet Bandwidth Calculation

Hi driera,

To answer the rest of your questions about the implementation of CobraNet in the NIONs:

The CobraNet configuration in the NIONs is configurable to up to 32 inputs by 32 outputs. The maximum number of inputs is 32 and the maximum number of outputs is 32. You can use all 32x32 channels at the same time or in any combination equal to or less than 32 channels per input or output. So, if you needed 24 inputs by 16 outputs, that would be fine. Likewise, 8 inputs by 28 outputs, you can do that, too. You essentially have up to 32 inputs and 32 outputs available and you can use anything less than that.  You can NOT do something like 48x16 with one NION, you would need to use two NIONs and XDAB them together.

Yes, you are correct that the CobraNet Ethernet network interface on the NION is a full duplex 100Mb/s Ethernet connection. This connection should be allowed to auto-negotiate its speed with the network switch, even though it should settle on 100Mb full duplex.

Josh Millward
Burnt Orange Studios

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Re: Cobranet Bandwidth Calculation

Great. Thanks all for this info and your help. I found some pieces, but not enough to be sure what I am doing. I hope that this answers can be used by other users.
Thanks again.