I would like to know how many throughput we lost when we activate AES encryption (128 or 256) in a PTP670 radio link.
I can´t find in the manual any information about that. It is not take in consideration to calculate the throughput of a PTP670 link:
To calculate the data rate capacity of a PTP 670 link, proceed as follows: 1 Use the tables in Data capacity in PTP topology on page 3-80 to look up the data throughput capacity rates (Tx, Rx and Both) for the required combination of: • Link Symmetry • Link Mode Optimization • Modulation Mode • Channel Bandwidth 2 The tables contain data rates for links of zero range. Use the range adjustment graphs to look up the Throughput Factor that must be applied to adjust the data rates for the actual range of the link. 3 Multiply the data rates by the Throughput Factor to give the throughput capacity of the link.
You don't lose any data capacity through use of AES encryption in PTP 650/670/700. That is why there is no mention in the User Guide. Perhaps we should add a note to make this clearer.
The procedure you describe above is accurate, but a little bit tedious. Another way to find link capacity is to use LINKPlanner.
The data path in PTP 650/670/700 is in hardware, and there is no limit on frame processing rate, except for the inherent limit set by the link capacity and the smallest Ethernet frame size (64 bytes).
There is a small reduction in data link capacity for smaller Ethernet frame size, because the PTP 670 wireless MAC layer adds a two-byte overhead. For example, PTP 670 sends 66 bytes over the radio for a 64 byte Ethernet frame. The capacity lost to this overhead is slightly greater for small frames than for large frames.