Once the URL address of the website is entered in the URL window, the browser starts to establish a connection between the transport layer and itself. The UDP (User Datagram Protocol) packet with a designation port of 53 is sent to the DNS (Domain Service Provider) server to request the ip address of the website. Once the ip address is returned from the server, Transport Layer will send a SYN PACKET to the server that stores the website. Correspondingly the server will send a SYN-ACK PACKET, if it accepts the request. Then the PC will send another SYN packet and the webpage will start to load into our PC. Now the connection is made between the BROWSER and WEBSERVER and the data packets will start to transmit between them.
Data packet: It is a stream of data bytes that contains both the header and the web page data.
So in TCP/IP, once the connection is made between the application and the web server, all the data is transmitted as data packets. So it may affect the application performance in the following ways:
- Data packets may get lost, so TCP asks for retransmission of data, obviously it affects the response time of the application
- When concurrent users log into the application, there may be a possibility of traffic in the data packet transmission
- Lower band width affects the application performance
- Lower bandwidth will allow sending few data packets per time slot, so it requires more time for amount of data than higher bandwidth transmission
- When the ROUTERS having different MTU values, it affect the application performance
Router R1 and Router R3 both have an MTU of 1500 bytes (the TCP/IP maximum) but Router two (R2) has an MTU of 1000 bytes. As data is being sent from the web server to your PC, R3 will receive the packets first. R3 can sense the MTU of R2 because each of them have a connection on a common network. R3 will then fragment every packet it gets from the web server into two packets at the IP layer (for example, one with an MTU of 1000 bytes and the other with an MTU of 500 bytes) before they are transmitted to R2. So the fragmentation between the routers will affect the application performance.
Thus, the application performance not only depends on the application code, the hardware configuration of the server but it also depends on network parameters as they carry the data between the server and client, whatever the technology in which the application is built.