When a connection is established, the two ends agree to use the smaller of each end's value. The default is 8192. A too large RWIN will result in greater loss of data if a packet is lost or damaged. A too small RWIN will be very slow, as each packet will have to be acknowledged before the next packet is sent. According to Microsoft, enabling these options may improve network performance in certain situations, such as communicating over a satellite link.
Satellites links are high bandwidth, but also very high latency, unlike cable.
Most useful when employed with TCP large windows. This mechanism is useful when the network is intermittently congested. The default is 128. To Live value set in the header of outgoing IP packets. The TTL determines the maximum amount of time an IP packet can live in the network without reaching its destination.