Difference between IEEE 802.3, 802.4 and 802.5

IEEE 802 specifies to a group of IEEE standards. IEEE standards 802 are used for controlling the Local Area Network and Metropolitan Area Network. The user layer in IEEE 802 is serviced by the two layers- the data link layer and the physical layer. The generally uses specifications of IEEE 802 are:

• IEEE 802.3 The IEEE 802.3 standard determines the CSMA/CD access control protocol. The best known scheme for controlling a local area network on a bus structure is carrier sense multiple action with collision detection(CSMA/CD).
• IEEE 802.4 IEEE 802.4 describes a token bus LAN standards.In token passing methods, stations connected on a bus are arranged in a logical ring. In this method only the station having token(token holder)is being permitted to transmit frames.
• IEEE 802.5 IEEE 802.5 describes the token ring standards. In a token ring a special bit pattern, called the token, circulates around the ring whenever all stations are idle.The sequence of token is determined by the physical locations of the stations on the ring.

Let’s see the difference between IEEE 802.3, 802.4 and 802.5 :-

S.No.	IEEE 802.3	IEEE 802.4	IEEE 802.5
1.	Topology used in IEEE 802.3 is Bus Topology.	Topology used in IEEE 802.4 is Bus or Tree Topology.	Topology used in IEEE 802.5 is Ring Topology.
2.	Size of the frame format in IEEE 802.3 standard is 1572 bytes.	Size of the frame format in IEEE 802.4 standard is 8202 bytes.	Frame format in IEEE 802.5 standard is of the variable size.
3.	There is no priority given in this standard.	It supports priorities to stations.	In IEEE 802.5 priorities are possible
4.	Size of the data field is 0 to 1500 bytes.	Size of the data field is 0 to 8182 bytes.	No limit is on the size of the data field.
5.	Minimum frame required is 64 bytes.	It can handle short minimum frames.	It supports both short and large frames.
6.	Efficiency decreases when speed increases and throughput is affected by the collision.	Throughput & efficiency at very high loads are outstanding.	Throughput & efficiency at very high loads are outstanding.
7.	Modems are not required.	Modems are required in this standard.	Like IEEE 802.4, modems are also required in it.
8.	Protocol is very simple.	Protocol is extremely complex.	Protocol is moderately complex.
9.	It is not applicable on Real time applications, interactive Applications and Client-Server applications.	It is applicable to Real time traffic.	It can be applied for Real time applications and interactive applications because there is no limitation on the size of data.