Unit 5 PROVIDING NETWORK SERVICES Prepared By Shamsa

Unit. 5 PROVIDING NETWORK SERVICES Prepared By: Shamsa Alhassouni

Lesson Objectives: Understand how clients and servers interact Understand how web pages are requested Understand what happens when using a domain name

How do clients and servers interact

What are the routine services you use over networks Online Booking Online shopping Send and receive Emails Update social media status All these services rely on Client and server interaction

How client and severs interact § § § One of the most common way to organize LAN is Client/Server Topology in which many clients will be connected to one end source. A server : is a high end computer running software application (web server) that provides services for the other hosts connected to the network Services includes: o o o Logins and security File and printer sharing Security and management Internet access Web sites and email services Downloading of applications and music

How client and severs interact § There are different types of servers providing the different services Types of Servers Prepared By: Shamsa Alhassouni

Request A Web Page

Request web page Request a website : www. google. ae Server responds carrying a Function: sending the requested document back to the client Clients running web browser software Prepared By: Shamsa Alhassouni

Request web page A web server : is usually in a part of the network with other servers called a server farm, or within a data center. Server Farm A data center can take up one room or more floors, or an entire building. Data centers very expensive to build and keep. For this reason, only large organizations use privately built data centers to house their data and provide services to users 9

Serving up Webpage

Serving up web pages Ø when requesting a web page Ø Uniform Resource Locator (URL) identifies the following: • Protocol used (HTTP) • Domain name • Location of the resource on the server. Domain Name Protocol File Name Folder Name Prepared By: Shamsa Alhassouni

Domain Name Service • DNS : is a protocol for how computers exchange data on the internet and private networks • This is known as the TCP/IP protocol suite. • Its main job is to turn the domain name into IP address , its like a phone book. Prepared By: Shamsa Alhassouni

What happens when using a domain name 3. Root Servers Do n’t Kn ow Request Don’t Know 4. TLD Servers Stores domain address information Re qu es t 2. ISP Server Cashe memory 1 DNS Cache of client Request st e qu e R Domain Available IP Address is 74. 125. 44. 25 4. Authoritative Name Servers Knows everything about domains including IP addresses Prepared By: Shamsa Alhassouni

Book Activity P-190 1 2 4 3