How to Calculate the Actual Available Bandwidth at the Data Link Layer?

Hi friend.

According to the T-CONT principle in the DBA, 8000 frames are transmitted per second. If the uplink bandwidth is fixed at 1 m, the number of bytes in a GEM frame = Assigned bandwidth (mbps)/Sampling rate = 1mbps/8000 = 125kbps = 16 bytes

Each GEM has five bytes of overhead. That is, the efficiency is as follows:

Frame length – Frame header/frame length = 16 - 5 / 16 = 68.75%;

When the bandwidth exceeds 5 m, the GEM frame adaptive slicing function needs to be considered. Currently, the chip adaptive slicing length is 80 bytes. When the bandwidth exceeds 5 m, the actual bandwidth efficiency is calculated as follows:

Frame Length – Frame Header/Frame Length = 80 - 5 / 80 = 93.75%

Therefore, the theoretical calculation results for different bandwidths are as follows:

Thanks.