Quickest way is to go into
http://192.168.0.1/cgi-bin/VmRouterS...perationCfgCgi and if your downstream rate is 220000000 bits then you have 200. It's set at 220 I think but you actually can get a max of 209 throughput due to the overheads.
I am pretty sure that symbol rate is 20Mbps but I might, and probably am wrong. I was just working on 2048 being 2MB etc.