TCP/IP: Advantages and Disadvantages

This page explores the benefits and drawbacks of TCP/IP (Transmission Control Protocol/Internet Protocol).

What is TCP/IP? (Introduction)

• It establishes a connection-oriented service.
• It is defined in RFC793.
• It’s considered a highly reliable connection due to the presence of SYN/ACK fields.
• The TCP header, containing the protocol field with a value of “0x06” in the IP header, is detailed below.

The TCP header includes: source port, destination port, sequence number, acknowledgment number, header length, flags (U, A, P, R, S, F), window, checksum, pointer, and some padding bits.

• TCP/IP uses a continuous stream of ordered data, fed from the upper layer and segmented before transmission. It utilizes a window size to protect buffer space and manage packet routing. This flow control mechanism is crucial in TCP/IP.
• It performs multiplexing and demultiplexing of applications based on unique port address fields.
• It’s a reliable in-order byte-stream protocol.
• As depicted in Figure 1, TCP is used at the 4th layer (Transport Layer) and IP is used at the 3rd layer (Network Layer) of the OSI model.

Figure 1: TCP/IP stack compared to OSI stack

Figure 2: TCP Header

Figure 3: IPV4 header

Figures 2 and 3 illustrate the fields within the TCP and IP headers, respectively.

Figure 4: TCP Connection Establishment and Termination

Figure 4 outlines the TCP connection establishment and termination procedures. It employs a 3-way handshake (SYN, SYN-ACK, ACK) for connection establishment and the “FIN” flag for termination.

Benefits or Advantages of TCP/IP

Here are the benefits and advantages of TCP/IP:

• It’s an industry-standard and open protocol with a scalable architecture.
• TCP protocol is connection-oriented and utilizes sequence numbers unique to each packet. This ensures data delivery in the correct order without duplication.
• It incorporates flow control, error control, and congestion control mechanisms.
• Since the stack is embedded within the Operating System (OS), the kernel handles reassembly, acknowledgments, flow control, etc. This simplifies the tasks usually managed by the programmer.
• Routers can read TCP packets and prioritize them accordingly.
• TCP provides relatively better throughput, especially on modem or LAN connections.

Drawbacks or Disadvantages of TCP/IP

The following are the drawbacks or disadvantages of TCP/IP:

• It can be more complex to set up and maintain compared to NetBEUI or IPX/SPX.
• It can be slower than IPX/SPX and NetBEUI on networks with light to medium traffic.
• Handoff overhead can be significant.
• Centralized TCP/IP domain assignment requires registration and associated costs.
• TCP/IP cannot conclude transmission until all data in transit has been explicitly acknowledged.
• TCP doesn’t inherently define block boundaries; the programmer needs to implement their own.