Final answer:
In TCP, if incoming packets arrive faster than they can be transmitted, flow control mechanisms like windowing prevent packet loss by instructing the sender to slow down, thereby ensuring the network buffer is not overwhelmed.
Step-by-step explanation:
When the network cannot transmit data as fast as incoming packets arrive in TCP (Transmission Control Protocol), the protocol's flow control mechanisms are engaged to prevent packet loss. TCP uses a mechanism known as "windowing" where the receiver specifies how much data it can process at a time (the window size). If incoming packets exceed this limit, the sender is instructed to pause or slow down sending more data. This helps manage the data flow to match the receiver's processing ability, thereby preventing the network buffer from becoming overloaded. If the buffer is filled and new data arrives before space is freed up, the excess packets could be dropped, leading to retransmissions that affect the network's performance.