So far, we have covered networking activities at the physical, link, and network layers of the Internet Protocol stack. This chapter focuses on foundations of layer 4, the transport layer. We study several techniques for Transmission Control Protocol (TCP) congestion control. These techniques use a form of end-to-end congestion control in a TCP session when a sender sends a packet (segment) and a receiver acknowledges receipt of the packet. This chapter covers the following topics:
• Overview of the transport layer
• User Datagram Protocol (UDP)
• Transmission Control Protocol (TCP)
• Mobile transport protocols
• TCP congestion control
We first take a close look at layer 4, the transport layer, and ...