There are two fundamental protocols in the transport layer 1. TCP Transmission Control Protocol-- connection-oriented protocol 2. UDP User Datagram Protocol -- connectionless protocol Connection-oriented communication : establishes a logical (virtual) connection prior to sending data. Connectionless communication : sends data right away without establishing a logical connection Qn why do we have transport layer protocal? IP provides a weak, but efficient service model (best-effort ) How should hosts send into the network? i.)Flow Control ii.) Too fast is bad; too slow is not efficient IP packets are addressed to a host How to decide which application gets which packets? NOTE TRASPORT LAYER IS RESPONSIBLE FOR PROCESS TO PROCESS DELIVERY PORTS port is a communication endpoints Since there are many applications running on a co...
There are two fundamental protocols in the transport layer
alert('Hello')
1. TCP Transmission Control Protocol-- connection-oriented protocol
2. UDP User Datagram Protocol -- connectionless protocol
Connection-oriented communication: establishes a logical (virtual) connection prior to sending data.
Connectionless communication: sends data right away without establishing a logical connection
Qn why do we have transport layer protocal?
- IP provides a weak, but efficient service model (best-effort)
- How should hosts send into the network?i.)Flow Controlii.) Too fast is bad; too slow is not efficient
- IP packets are addressed to a host
How to decide which application gets which packets?
NOTE TRASPORT LAYER IS RESPONSIBLE FOR PROCESS TO PROCESS DELIVERY
PORTS
port is a communication endpoints
Since there are many applications running on a computer, there is a need to decide which application gets which packet.
A port number is a way to identify a specific application (process) to which an Internet or other network message is to be forwarded when it arrives at a server
It is essentially a memory space denoted by a 16-bit non-negative integer ranging from 0-65,535 inclusive.
One port is linked to only one application
One application may use many ports for different purposes (e.g. FTP: 20, 21)
TYPES OF PORT NUMBERS
- Well-known Ports: range 0-1023
- Registered Ports: range 1024-49151
- Dynamic ports: range 49152-65535
These ports are reserved for services and applications.
Everyone agrees what services run on these ports. E.g. ssh:22, http:80
By defining these well-known ports for server applications, client applications can be programmed to request a connection to that specific port and its associated service.
Client must know server’s port.
The Well Known Ports are assigned by the IANA and on most systems can only be used by system (or root) processes or by programs executed by privileged users.
Comments