Enterprise Integration Patterns: Designing, Building, and Deploying Messaging Solutions (Addison-Wesley Signature Series (Fowler))

by Hohpe Gregor

One of the key features of the TCP protocol is to ensure in-sequence delivery of packets over the network. In reality, each packet may be routed through a different network path, so out-of-sequence packets occur quite frequently. The receiver maintains a circular buffer that is used as a sliding window. Receiver and sender negotiate on the number of packets to send before each acknowledgment. Because the sender waits for an acknowledgment from the receiver, a fast sender cannot outpace the receiver or cause the buffer to overflow. Specific rules also prevent the so-called Silly Window Syndrome, where sender and receiver could fall into a very inefficient, one-packet-at-a-time mode