OSI (Open Systems Interconnect)

2.2 Identify the seven layers of the OSI (Open Systems Interconnect) model and their functions.

APPLICATION layer 7	Gives user applications access to network. This layer represents the services, that directly support the user applications such as software for file transfers, database access, and E-mail
PRESENTATION layer 6	The presentation layer, usually part of an operating system, converts incoming and outgoing data from one presentation format to another. Presentation layer services include data encryption and text compression.
SESSION layer 5	Opens manages, and closes conversations between two computers. It performs name recognition and the functions such as security, needed to allow two applications to communicate over the network, also provides error handling.
TRANSPORT layer 4	This layer provides transparent transfer of data between end systems, or hosts, and is responsible for end-to-end error recovery and flow control. It ensures complete data transfer. Sequences data packets, and requests retransmission of missing packets. It also repackages messages for more efficient transmission over the network.
NETWORK layer 3	Establishes, maintains and terminates network connections. Routes data packets across network segments. Translates logical addresses and names into physical addresses.
DATA LINK layer 2	Transmits frames of data from computer to computer on the same network segment. Ensures the reliability of the physical link established at layer 1. Standards define how data frames are recognized and provide the necessary flow control and error handling at the frame set. The data link layer is divided into two sublayers: The Media Access Control (MAC) layer and the Logical Link Control (LLC) layer. The MAC sublayer controls how a computer on the network gains access to the data and permission to transmit it. The LLC layer controls frame synchronization, flow control and error checking.
PHYSICAL layer 1	The Physical layer defines all the electrical and physical specifications for devices. This includes the layout of pins, voltages, and cable specifications. Hubs, repeaters and network adapters are physical-layer devices. Defines cabling and connections. Transmits data over the physical media.

2.3 Identify the OSI (Open Systems Interconnect) layers at which the following network components operate:

> Hubs, Switches, Bridges, Routers, NICs (Network Interface Card), WAPs (Wireless Access Point)

APPLICATION layer 7	DHCP DNS FTP HTTP IMAP4 IRC NNTP XMPP MIME POP3 SIP SMTP SNMP SSH TELNET BGP RPC RTP RTCP TLS/SSL SDP SOAP L2TP PPTP
PRESENTATION layer 6	AFP, AppleShare File Protocol GIF ICA Citrix Systems Core Protocol JPEG, Joint Photographic Experts Group LPP, Lightweight Presentation Protocol NCP, NetWare Core Protocol NDR, Network Data Representation PNG, Portable Network Graphics TIFF, Tagged Image File Format XDR, eXternal Data Representation X.25 PAD, Packet Assembler/Disassembler Protocol
SESSION layer 5	ADSP, AppleTalk Data Stream Protocol ASP, AppleTalk Session Protocol H.245, Call Control Protocol for Multimedia Communication iSNS, Internet Storage Name Service L2F, Layer 2 Forwarding Protocol L2TP, Layer 2 Tunneling Protocol NetBIOS, Network Basic Input Output System PAP, Printer Access Protocol PPTP, Point-to-Point Tunneling Protocol RPC, Remote Procedure Call Protocol RTP, Real-time Transport Protocol RTCP, Real-time Transport Control Protocol SMPP, Short Message Peer-to-Peer SCP, Secure Copy Protocol SSH, Secure Shell ZIP, Zone Information Protocol
TRANSPORT layer 4	AEP, AppleTalk Echo Protocol ATP, AppleTalk Transaction Protocol CUDP, Cyclic UDP DCCP, Datagram Congestion Control Protocol FCP, Fiber Channel Protocol FCIP, Fiber Channel over TCP/IP IL, IL Protocol iSCSI, Internet Small Computer System Interface NBP, Name Binding Protocol NetBEUI, NetBIOS Extended User Interface SPX, Sequenced Packet Exchange RTMP, Routing Table Maintenance Protocol SCTP, Stream Control Transmission Protocol SCSI, Small Computer System Interface TCP, Transmission Control Protocol UDP, User Datagram Protocol
NETWORK layer 3	Routers - Switches - Bridges IP/IPv6, Internet Protocol DVMRP, Distance Vector Multicast Routing Protocol ICMP, Internet Control Message Protocol IGMP, Internet Group Multicast Protocol PIM-SM, Protocol Independent Multicast Sparse Mode PIM-DM, Protocol Independent Multicast Dense Mode IPSec, Internet Protocol Security IPX, Internetwork Packet Exchange RIP, Routing Information Protocol NLSP, NetWare Link State Protocol X.25, Packet Level Protocol X.75, Packet Switched Signaling Between Public Networks DDP, Datagram Delivery Protocol
DATA LINK layer 2	ARCnet ATM Cisco Discovery Protocol (CDP) Controller Area Network (CAN) Econet Ethernet Fiber Distributed Data Interface (FDDI) Frame Relay High-Level Data Link Control (HDLC) IEEE 802.2 (provides LLC functions to IEEE 802 MAC layers) IEEE 802.11 wireless LAN LocalTalk Multiprotocol Label Switching (MPLS) Point-to-Point Protocol (PPP) Serial Line Internet Protocol (SLIP StarLan Token ring
PHYSICAL layer 1	Network adapters - Repeaters - Ethernet hubs - Modems - Wireless 802.11x xDSL IRDA physical layer USB physical layer Firewire EIA RS-232, EIA-422, EIA-423, RS-449, RS-485 ITU Recommendations: see ITU-T DSL ISDN T1 and other T-carrier links, and E1 and other E-carrier links 10BASE-T, 10BASE2, 10BASE5, 100BASE-TX, 100BASE-FX, 100BASE-T, 1000BASE-T, 1000BASE-SX and other varieties of the Ethernet physical layer Wireless 802.11x SONET/SDH GSM radio interface Bluetooth physical layer IEEE 802.11x Wi-Fi physical layers

2.4 Differentiate between the following network protocols in terms of routing, addressing schemes, interoperability and naming conventions: