Question: In the discussion of node-by-node window flow control, it was assumed that node i can send a permit back to its predecessor (i - 1) once it releases a packet to the DLC of link (i, i + 1). The alternative is for node i to send the permit when it receives the DLC acknowledgment that the packet has been received correctly at node i + 1. Discuss the relative merits of the two schemes. Which scheme requires more memory? What happens when link (i, i + 1) is a satellite link?