No "rwnd" option to "ip route" for managing the receive window?

**Context:** I'm doing some self-guided studying on TCP Window shaping. The scenario I'm trying to control for are clients which will be pulling down large amounts of data in addition to their normal workload. I can't really use tc since I'm on the receiving end on most of the data so packet classifying/scheduling/shaping is a moot point. trickle doesn't work like how I would want it to (added abstraction layer and there are multiple types of programs that just won't work with it). I was also unable to find a way to do this using iptables even though several modules looked like they were close to what I was wanting to achieve. **Question:** I'm looking at the man page for the ip route add command which has options for controlling the TCP window size. The relevant options are: window NUMBER the maximal window for TCP to advertise to these destinations, measured in bytes. It limits maximal data bursts that our TCP peers are allowed to send to us. cwnd NUMBER (2.3.15+ only) the clamp for congestion window. It is ignored if the lock flag is not used. initcwnd NUMBER the maximum initial congestion window (cwnd) size in MSS of a TCP connection. initrwnd NUMBER (2.6.33+ only) the initial receive window size for connections to this destination. Actual window size is this value multiplied by the MSS of the connection. The default value is zero, meaning to use Slow Start value. My questions are: 1. Why is there an option for explicitly setting the clamp on the congestion window (i.e cwnd) but not on the receive window (such as rwnd)? 2. Is the idea that I will set window (whose description reads like it affects congestion and receive windows equally) if I want to control the receive window?