What Is Connection-Oriented Service?
Connection-oriented is a means of transmitting data in which the devices at the end points use a preliminary protocol to establish an end-to-end connection before any data is sent. In telecommunication, the connection-oriented services is most often described as ‘’reliable network service’’ because the data streams/packets are delivered to the receiver in the same order in which they have been sent by the sender.
A connection-oriented service requires an established connection between peers before data can be sent between the connected terminals. A good connection-oriented service can often deliver more quality than large bandwidth. It can be a circuit-switched connection or a virtual circuit connection in a packet-switched network.
Advantages of Connection-Oriented Service
- It is a reliable connection service.
- Duplication of data packets does not arise.
- Cases of congestion do not arise.
- Data packets sequencing is guaranteed.
- Suitable for long connections.
Disadvantages Of Connection-Oriented Service
- Resource allocation is mandatory before communication.
- The speed of connection is slower. There is much time taken for establishing and relinquishing the connection.
- No alternative ways to continue with communication incase of network congestion or router failures.
What Is Connection-Less Service?
A connectionless service is a way of transmitting data communication between two terminals where the sender sends data packets to its destination without establishing a connection to the destination. A good example of connectionless systems is LANs. LANs enables each computer to transmit data packets as soon as it can access the network. In telecommunications, connectionless protocols are usually described as stateless because the end points have no protocol-defined way to remember where they are in a conversation of message exchanges.
In connectionless transmissions, the service provider usually cannot guarantee that there will be no loss, error insertion, mis-delivery, duplication or out-of-sequence delivery of the packets. A connectionless service has an advantage over a connection-oriented communication, in that it has low overheads. It allows for multicast and broadcast operations in which the same data are transmitted to several recipients in a single transmission.
Advantages of Connectionless Service
- There are usually low overheads involved.
- It is to broadcast or multicast messages to multiple recipients.
- No circuit setup. Therefore, it takes a fraction of a minute to establish connection.
- It has alternative path of data transmission in case of network congestion or router failures.
Disadvantages Of Connectionless Service
- It is susceptible to network congestion.
- It is not a reliable connection as possibility of loss of packets, wrong deliver or duplication is high.
- Each data packet needs lengthy fields because it is supposed to hold all the destination address and the routing information.
Connection-Oriented Services Characteristics
- Connection-oriented service is related to the telephone system.
- It is implemented either using circuit witching or VCs.
- Connection-oriented service is more reliable as it makes the virtual connection before sending packets and ensures delivery of packets to the destination.
- All the packets between sender and destination follow the same path.
- There is some degree of delay in transfer of information, however once connection has been established, transfer becomes faster.
- It requires authentication of the destination node before transferring data.
- It is comparatively slower to connection-less service.
- Congestion is not possible in connection-oriented service.
- It is suitable for long and steady communication.
- Connection is established through the process of signaling.
- It is possible to retransmit the lost data bits.
- Resource allocation is necessary.
- Bandwidth requirement is higher in connection-oriented service.
- TCP is an example of connection-oriented protocol.
Connection-Less Services Characteristics
- Connection-less service is related to the postal system.
- It is implemented using packet switching.
- Connection-less service does not ensure reliability on packet transmission.
- Not necessary all packets transmitting between sender and receiver follows the same path.
- There is no delay due to absence of established connection phase.
- It transfers the data message without authenticating destination.
- It is faster when compared to connection-oriented.
- Congestion is possible in connection-less service.
- It is suitable for bursty transmissions.
- There is no concept of signaling.
- It is not possible to re-transmit the lost data bits.
- Resource allocation is not necessary.
- Bandwidth requirement is low in connection-less services.
- UDP is an example of a connection-less protocol.
Connection-Oriented Vs. Connection-less Services In Tabular Form
|BASIS OF COMPARISON||CONNECTION-ORIENTED SERVICES||CONNECTION-LESS SERVICE|
|Relation||It is related to the telephone system.||It is related to the postal system.|
|Implementation||It is implemented either using circuit witching or VCs.||It is implemented using packet switching.|
|Reliability||It is more reliable as it makes the virtual connection before sending packets and ensures delivery of packets to the destination.||It does not ensure reliability on packet transmission.|
|Path||All the packets between sender and destination follow the same path.||Not necessary all packets transmitting between sender and receiver follows the same path.|
|Delay||There is some degree of delay in transfer of information, however once connection has been established, transfer becomes faster.||There is no delay due to absence of established connection phase.|
|Authentication||It requires authentication of the destination node before transferring data.||It transfers the data message without authenticating destination.|
|Speed||It is comparatively slower to connection-less service.||It is faster when compared to connection-oriented.|
|Congestion||Congestion is not possible.||Congestion is possible.|
|Suitability||It is suitable for long and steady communication.||It is suitable for bursty transmissions.|
|Signaling||Connection is established through the process of signaling.||There is no concept of signaling.|
|Retransmission Of Lost Bits||It is possible to retransmit the lost data bits.||It is not possible to retransmit the lost data bits.|
|Resource Allocation||Resource allocation is necessary.||Resource allocation is not necessary.|
|Bandwidth Requirement||Bandwidth requirement is higher.||Bandwidth requirement is low.|
|Example||TCP (transmission control protocol) is an example of connection-oriented protocol.||UDP (User Datagram Protocol) is an example of a connectionless protocol.|
Also Read: Difference Between LAN,WAN And MAN