Topology
Topology defines the structure of the network of how all the components are interconnected to each
other. There are two types of topology: physical and logical topology.
Types of Network Topology
Physical topology is the geometric representation of all the nodes in a network. There are six types of
network topology which are Bus Topology, Ring Topology, Tree Topology, Star Topology, Mesh
Topology, and Hybrid Topology.
1) Bus Topology
1. The bus topology is designed in such a way that all the stations are connected through a
single cable known as a backbone cable.
2. Each node is either connected to the backbone cable by drop cable or directly connected to
the backbone cable.
3. When a node wants to send a message over the network, it puts a message over the
network. All the stations available in the network will receive the message whether it has
been addressed or not.
4. The bus topology is mainly used in 802.3 (ethernet) and 802.4 standard networks.
5. The configuration of a bus topology is quite simpler as compared to other topologies.
6. The backbone cable is considered as a "single lane" through which the message is broadcast
to all the stations.
Advantages of Bus topology:
1. Low-cost cable: In bus topology, nodes are directly connected to the cable without passing
through a hub. Therefore, the initial cost of installation is low.
2. Moderate data speeds: Coaxial or twisted pair cables are mainly used in bus-based networks
that support upto 10 Mbps.
3. Familiar technology: Bus topology is a familiar technology as the installation and
troubleshooting techniques are well known, and hardware components are easily available.
4. Limited failure: A failure in one node will not have any effect on other nodes.
Disadvantages of Bus topology:
1. Extensive cabling: A bus topology is quite simpler, but still it requires a lot of cabling.
, 2. Difficult troubleshooting: It requires specialized test equipment to determine the cable
faults. If any fault occurs in the cable, then it would disrupt the communication for all the
nodes.
3. Signal interference: If two nodes send the messages simultaneously, then the signals of both
the nodes collide with each other.
4. Reconfiguration difficult: Adding new devices to the network would slow down the network.
5. Attenuation: Attenuation is a loss of signal leads to communication issues. Repeaters are
used to regenerate the signal.
2) Ring Topology
1. Ring topology is like a bus topology, but with connected ends.
2. The node that receives the message from the previous computer will retransmit to the next
node.
3. The data flows in one direction, i.e., it is unidirectional.
4. The data flows in a single loop continuously known as an endless loop.
5. It has no terminated ends, i.e., each node is connected to other node and having no
termination point.
6. The data in a ring topology flow in a clockwise direction.
7. The most common access method of the ring topology is token passing.
a. Token passing: It is a network access method in which token is passed from one node
to another node.
b. Token: It is a frame that circulates around the network.
Working of Token passing
1. A token moves around the network, and it is passed from computer to computer until it
reaches the destination.
2. The sender modifies the token by putting the address along with the data.
3. The data is passed from one device to another device until the destination address matches.
Once the token received by the destination device, then it sends the acknowledgment to the
sender.
4. In a ring topology, a token is used as a carrier.
Advantages of Ring topology:
1. Network Management: Faulty devices can be removed from the network without bringing
the network down.
Topology defines the structure of the network of how all the components are interconnected to each
other. There are two types of topology: physical and logical topology.
Types of Network Topology
Physical topology is the geometric representation of all the nodes in a network. There are six types of
network topology which are Bus Topology, Ring Topology, Tree Topology, Star Topology, Mesh
Topology, and Hybrid Topology.
1) Bus Topology
1. The bus topology is designed in such a way that all the stations are connected through a
single cable known as a backbone cable.
2. Each node is either connected to the backbone cable by drop cable or directly connected to
the backbone cable.
3. When a node wants to send a message over the network, it puts a message over the
network. All the stations available in the network will receive the message whether it has
been addressed or not.
4. The bus topology is mainly used in 802.3 (ethernet) and 802.4 standard networks.
5. The configuration of a bus topology is quite simpler as compared to other topologies.
6. The backbone cable is considered as a "single lane" through which the message is broadcast
to all the stations.
Advantages of Bus topology:
1. Low-cost cable: In bus topology, nodes are directly connected to the cable without passing
through a hub. Therefore, the initial cost of installation is low.
2. Moderate data speeds: Coaxial or twisted pair cables are mainly used in bus-based networks
that support upto 10 Mbps.
3. Familiar technology: Bus topology is a familiar technology as the installation and
troubleshooting techniques are well known, and hardware components are easily available.
4. Limited failure: A failure in one node will not have any effect on other nodes.
Disadvantages of Bus topology:
1. Extensive cabling: A bus topology is quite simpler, but still it requires a lot of cabling.
, 2. Difficult troubleshooting: It requires specialized test equipment to determine the cable
faults. If any fault occurs in the cable, then it would disrupt the communication for all the
nodes.
3. Signal interference: If two nodes send the messages simultaneously, then the signals of both
the nodes collide with each other.
4. Reconfiguration difficult: Adding new devices to the network would slow down the network.
5. Attenuation: Attenuation is a loss of signal leads to communication issues. Repeaters are
used to regenerate the signal.
2) Ring Topology
1. Ring topology is like a bus topology, but with connected ends.
2. The node that receives the message from the previous computer will retransmit to the next
node.
3. The data flows in one direction, i.e., it is unidirectional.
4. The data flows in a single loop continuously known as an endless loop.
5. It has no terminated ends, i.e., each node is connected to other node and having no
termination point.
6. The data in a ring topology flow in a clockwise direction.
7. The most common access method of the ring topology is token passing.
a. Token passing: It is a network access method in which token is passed from one node
to another node.
b. Token: It is a frame that circulates around the network.
Working of Token passing
1. A token moves around the network, and it is passed from computer to computer until it
reaches the destination.
2. The sender modifies the token by putting the address along with the data.
3. The data is passed from one device to another device until the destination address matches.
Once the token received by the destination device, then it sends the acknowledgment to the
sender.
4. In a ring topology, a token is used as a carrier.
Advantages of Ring topology:
1. Network Management: Faulty devices can be removed from the network without bringing
the network down.
