Analysis of Ring Topology: Data Transfer, Advantages, and Applications

This report provides a comprehensive introduction to ring topology, explaining its fundamental characteristics as a network configuration where devices are connected in a circular data path. It details the data transfer protocols used, including token passing and Time Division Multiplexing (TDM), and highlights how these mechanisms prevent data collisions and manage data flow. The report discusses the advantages of ring topology, such as reduced risk of packet collisions, faster data transfer speeds, robustness, and the elimination of the need for a central server. It also explains key concepts like ring latency, cycle time, and token holding time, along with different token reinsertion methods. The report notes that ring topologies are used in LANs and WANs.

Ring Topology

Introduction
The ring topology is described as the network configuration which connects the devices creating
circular data path. The devices in the network are connected to two other devices forming a
circle. All the devices connected in this way create the ring network. In this network, the data
packet travels from one device to the other until the destination is reached. Typically, the
networks of this topology allows the data to travel in one direction only. Such networks are
called as unidirectional network. Other networks facilitate the data for moving in both direction.
The connection in ring topology is dependent on the every individual connection. The network
operates only when all other connections are working. Such topology is used in LANs (local area
networks) and WANs (wide area networks). Based on the network type, the devices are
connected using an RJ-45 network cable and a coaxial cable. Previously, the networks in this
topology were used in offices, schools and buildings where the size of network is smaller.
Nowadays, the networks of this topology are used for stability, support and improved
performance. In the case of ring topology, every node functions as a repeater, when the node
receives the signal from another node, it regenerates the bits.
Data Transfer Protocol
In ring topology, the network defines the order of data sent by the stations. The stations are
connected with one another. The data is transferred in form of a three byte token. It travels
through the entire ring before reaching the destination. The networks of this topology also use
the Token Passing controlled access mechanism. The frames also travel in the direction of the
token and circulate the entire ring before reaching the destination.

In controlled access mechanisms, every station send data at different times. In other words, the
data transfer process is controlled by the Time Division Multiplexing (TDM). In TDM
communication process, the same channel transmits two or more digital signals. The incoming
signals in this case are divided into time slots of fixed length. The efficiency of the
communication process is directly proportional to the time-slot selection. Before initiating the
transfer process, the stations in a network seek information from others to know the right. In this
topology, only one station has the right to send the data. Therefore, the risk of collision can be
avoided.
In the token passing scheme of the ring topology, the token govern the data transfer scheme
between the logically connected stations. During the data transfer process, at first the token
travels from one station to check whether any node is transferring data. The token transfer is
done using the tokenbus. Each station is uses the bus for sending data to the next station. If a
station has a frame in queue for transmission while it receives the token, the frame is passed
before the token. If there is no frame, only the token is passed. After the frame is sent, the
stations wait for all other stations for sending the token. However, in this scheme, the problems
such as duplication or loss of token occur. The operation is also interrupted when a station is
removed or a new one is inserted.
The ring latency is the time required by a single bit for travelling around the ring. The latency
depends on a number of factors including the length and speed of data. The latency also depends
on the number of stations present in the ring. Finally, the latency is also dependent on the bit
delay or the time required by every station before transmission. The time required by a token for
completion of a revolution across the ring is described as the cycle time.

The token holding time (THT) is another concept associated n with the token ring passing
mechanism. THT is described as the optimum time during which the token is held by a frame.
The token reinsertion in the ring occurs in two ways. In case of delayed token reinsertion, the
sender transmits the data and waits until the packet returns after travelling through the ring.
When the sender receives the entire data packet again, the token is released. In this case, only
one packet travels through the ring at a time. On the contrary, in case of early reinsertion, the
sender releases the token after transmitting the data. In this case, it does not wait for the packet to
return. In this case, several packets remain present in the ring.
Advantages
The ring topology is advantageous in several ways. The benefits of this topology are as follow—
Lower Risk of Packet Collision: The data collision occurs when the data packets are being
transmitted simultaneously between the nodes in a network. Due to collision, the data packets get
fragmented and they are retransmitted. The data loss takes place due to the collision. Therefore,
the data collision reduces overall efficiency of the network. As an effect, the networks need to be
designed in such way so that the risk of data collusion reduces. In case of ring topology, the data
flows in circular direction. So, the risk of packet collision reduces.
Speed: The network speed is crucial for faster data transfer. The unidirectional ring topologies
ensure faster data transfer. However, the speed of data depends on the number of nodes. It is
more advantageous than bus topology even when the number of nodes is used.

Robust: The network topologies require being robust to deal with insertion or deletion of the
nodes. The ring topology is highly robust as the nodes can be inserted and deleted easily in this
type of network.
No Need of Server: The networks in the ring topology do not need any server. So, these
networks are simpler. The troubleshooting is also simpler in this network. The reduced need of
server has reduced the cost.