Figure 1-1: Basic Networking Concepts Client/Server Applications Most Internet applications are client/server applications Clients receive service from servers The client is often a browser C lient Server Program Program Services Client Computer Server computer 6
6 Figure 1-1: Basic Networking Concepts • Client/Server Applications – Most Internet applications are client/server applications – Clients receive service from servers – The client is often a browser Client Computer Server Computer Server Program Client Program Services
Part l: the nine elements of a Network Although the idea of network is simple, you must understand the nine elements found in most networks
Part II: The Nine Elements of a Network Although the idea of “network” is simple, you must understand the nine elements found in most networks
Figure 1-3: Elements of a Network Client Application Server Application Message(Frame) Access Switch Client Networks connect Server Computer applications on different computers Computer SWItC Switch Networks connect computers 2. Clients(fixed and mobile) and Mobile 3. Servers Client Outside World Wireless Access point Router 8
8 Figure 1-3: Elements of a Network Wireless Access Point Mobile Client Router Outside World Server Computer Client Computer Switch 1 Switch 2 Switch 3 Message (Frame) Access Line Trunk Line Client Application Server Application 1. Networks connect applications on different computers. Networks connect computers: 2. Clients (fixed and mobile) and 3. Servers
Figure 1-3: Elements of a Network Client application Server Application Message(Frame) Client Server Computer Computer Switch Computers(and routers) 3 usually communicate Mol by sending messages Cli called frames Outside World Wireless Access point Router
9 Figure 1-3: Elements of a Network Wireless Access Point Mobile Client Router Outside World Server Computer Client Computer Switch 1 Switch 3 Message (Frame) Trunk Line Client Application Server Application 4. Computers (and routers) usually communicate by sending messages called frames
Figure 1-3: Elements of a Network e Client Application Server Application Client Sends Sw1 Sends Maasage( Sw2 Sends Frame Frame Frame to Sw1 to sw2 To SW3 Client Switch 2 Computer Sw3 Sends Frame to ter Switch 1 Server Trunk Switch 3 ine. Switches forward Switch Outside Frames Sequentially World Access point Router 10
10 Figure 1-3: Elements of a Network Wireless Access Point Mobile Client Router Outside World Server Computer Client Computer Switch 4 Message (Frame) Trunk Line Client Application Server Application Switch 2 Switch 1 Switch 3 Client Sends Frame to Sw1 Sw1 Sends Frame to Sw2 Sw2 Sends Frame To Sw3 Sw3 Sends Frame to Server 5. Switches Forward Frames Sequentially