1. Internetworking Lecture # 2 Hassan Shuja 02/21/2006

2. Networking Protocols Networking Protocols Networking Protocols – Vendors developed their own networking protocols SNA – IBM SNA – IBM DECnet – DEC Minicomputers DECnet – DEC Minicomputers Apple – Appletalk Apple – Appletalk – International Organization for Standardization (ISO) takes on the task to develop a standard Open System Interconnection (OSI) developed Open System Interconnection (OSI) developed – U.S Department of Defense (DoD) begins to develop networking protocol TCP/IP TCP/IP

3. Networking Protocols Networking protocols Networking protocols – OSI suffers because of slow formal standardization process never succeeds in the marketplace TCP used by US government TCP used by US government – TCP/IP takes off and becomes the most widely used networking protocol

4. TCP TCP Protocol Stack TCP Protocol Stack

5. TCP TCP Ports TCP Ports

6. Network Devices Hub Hub – A layer 2 device that is used to connect network devices – When a packet is sent from one port, it is copied to all other ports Switch Switch – A layer 2 device that is used to connect network devices – When a packet is sent from one port, it is directly switched to the destination port

7. Network Devices Router Router – A layer 3 device that forwards packets across broadcast networks Firewall Firewall –A system designed to protect a computer network from unauthorized access

8. Packet Routing Address Resolution Protocol (ARP) Address Resolution Protocol (ARP) –Data traffic is routed using the network addresses –Data traffic is forwarded over a physical network using MAC addresses –ARP is a method used in TCP/IP suite to map network addresses to MAC addresses

9. Packet Routing Address Resolution Protocol (ARP) Address Resolution Protocol (ARP)

10. Local Area Network (LAN) Various LANs Various LANs – –A high-speed network that is bounded by a small geographic area Tends to encompass one broadcast domain Usually restricted to a building or floor Operates at the layer 1 and 2 of the OSI model Interconnected using a hub or switch

11. Local Area Network (LAN) Various LANs Various LANs – –Ethernet Technologies Ethernet Most commonly used Duplex – full/half Speed – 10/100/auto FDDI Token Ring

12. Local Area Network (LAN) Transmission Methods Transmission Methods –Unicast Single packet from source to destination Single packet from source to destination –Multicast Single packet that is sent to a specific subset of nodes Single packet that is sent to a specific subset of nodes –Broadcast Single packet that is sent to all nodes Single packet that is sent to all nodes