Knowledgebase: iDR Series > iDR-4
iDR-8 / iDR-4. Network Trafic
Posted by Chris Panks, Last modified by on 28 March 2011 12:24 PM
Each iDR on a network will send a broadcast once per second.
Each iDR that “hears” this broadcast will reply with a directed UDP message.

The data payload of the broadcast packet is 12 Bytes, which gives a total Ethernet packet size of 60 Bytes
(8 for the UDP header, plus 40 for the IP header, plus 14 for the Ethernet header, plus 6 padding at the end of the message).

The Ethernet packet size of the reply is also 60 bytes (though, remember this is a directed, not a broadcast packet).
Therefore two iDRs on a network would send 120bytes of broadcast messages, and 120bytes of directed replies to each other.

This would be approx 0.024% of the maximum bandwidth of 10baseT Ethernet.
This should be next to no load on any network.


Each iDR on the network sends a broadcast message with a total frame length of 60 Bytes once per second.

For each iDR System Manager that is connected to a unit the unit will send metering information.
This is done in 3 messages…

First with a total frame length of 322 Bytes 

Second with a total frame length of 130 Bytes

Third with a total frame length of 162 Bytes


These are sent every 40ms.


Other messages are done when required, at a 40ms frame rate - the most significant of these would be metering LEDs on the simulations,
which send a message each time they change colour - therefore depend on the dynamic qualities of the audio signal they represent.

The TCP stack may coalesce some of the messages reducing the overhead so these frame sizes are worst case.

In terms of percentage of 10baseT Ethernet bandwidth this relates to approximately…

iDR with no connections to it - 0.006%

For each iDR system manager connected - 1.5%


For 100baseTx these can be divided by 10, and for Giga bit networks routes this can be divided by 100.
No allowance has been made for network collisions & retransmits due to them - this depends on the number of network nodes,
the network topography (repeater hub verses switched, subnets etc), and the other network traffic.

This is a simplification of the system (for instance any iDR on the same subnet as another will reply to the others' broadcast and visa-versa,
so 2 iDRs with no connections will take 4 * 0.006% of a 10BaseT bandwidth, and 3 on the same subnet would take 9 * 0.006%, etc).