Bandwidth calculation for network project (example with IEC61850 Drivers).
the packet size depends on various parameters (communication protocol, lower communication layers, single or bulk transfers, network quality,...) and therefore no generic statements can be made.
We strongly recommend to do your own tests with reference parameters based on a specific project scope in order to receive valid assumptions.
IEC 61850, for example, offers either polling or spontaneous communication through reports.
If polling communication is used, it depends on the polling rate how often data is requested which leads to X byte per Y seconds network traffic.
The number of X can be read out of the standards (IEC 61850, MMS) and Y is then an application specific setting.
But the X bytes only referrer to the packet size of the actual message. The lower network layers (TCP, IP, …) add additional data overhead and this overhead is also influenced by network quality and other parameters.
So there is no linear function to exactly calculate the packet size for one signal and then scale it up to higher numbers.