what is upstream and downstream router
Downstream or download speed is the term given to the data that your computer receives from the Internet. Whenever you download music, pictures, webpages and other documents, you are using your computer's downstream bandwidth. Cable modems are typically rated at 1 to 2 megabits per second (Mbps).
With 16 downstream channels, the maximum raw throughput is 16 times that (608 Mbit/sec). Upstream channels use narrower channels of bandwidth between 200kHz and 6.4 MHz, but typically 3.2MHz with a typical throughput (in modern systems) of 27 Mbit/sec. 4 channels is 4 times that (108 Mbit/sec).