DOCSIS 3.0 throughput calculation
What is the actual DOCSIS 3.0 throughput you can get out of your cable connection at home? 42 Mbps? 38 Mbps? 35 Mbps? 32 Mbps? If you try to find the answer to this question using Google, you will find that there are multiple answers to this question, and although they are telling a different value, they are actually not all wrong.
A DOCSIS 3.0 Cable Modem can actually in theory provide download speeds up to 1 Gbps and upload speeds close to 250 Mbps and if it uses Channel Bonding (maximum bonding are usually 24×8 or 32×8), however MSOs will typically migrate their users to DOCSIS 3.1 for high speeds above 200-300 Mbps as it provides a higher efficiency.
The DOCSIS 3.0 Throughput Excel file provided here shows the calculation of the attainable throughput on a DOCSIS connection, in Downstream and Upstream, depending on several factors: the allocated bandwidth, the modulation order, the channel bonding. The calculation steps are shown per layer from Physical up to Layer 7, using exact calculations or estimations of the encapsulation effect on the actual throughput.
Let me know if you have any question or comment on this file (and especially if you find mistakes!).