Mahamood-ka
07-12-2013, 21:36
Table 18: OSI Reference Model Layer Summary
Group
#
Layer Name
Key Responsibilities
Data Type Handled
Scope
Common Protocols and Technologies
Lower Layers
1
Physical
Encoding and Signaling; Physical Data Transmission; Hardware Specifications; Topology and Design
Bits
Electrical or light signals sent between local devices
(Physical layers of most of the technologies listed for the data link layer)
2
Data Link
Logical Link Control; Media Access Control; Data Framing; Addressing; Error Detection and Handling; Defining Requirements of Physical Layer
Frames
Low-level data messages between local devices
IEEE 802.2 LLC, Ethernet Family; Token Ring; FDDI and CDDI; IEEE 802.11 (WLAN, Wi-Fi); HomePNA; HomeRF; ATM; SLIP and PPP
3
Network
Logical Addressing; Routing; Datagram Encapsulation; Fragmentation and Reassembly; Error Handling and Diagnostics
Datagrams / Packets
Messages between local or remote devices
IP; IPv6; IP NAT; IPsec; Mobile IP; ICMP; IPX; DLC; PLP; Routing protocols such as RIP and BGP
4
Transport
Process-Level Addressing; Multiplexing/Demultiplexing; Connections; Segmentation and Reassembly;
Acknowledgments and Retransmissions;
Flow Control
Datagrams / Segments
Communication between software processes
TCP and UDP; SPX; NetBEUI/NBF
Upper Layers
5
Session
Session Establishment, Management and Termination
Sessions
Sessions between local or remote devices
NetBIOS, Sockets, Named Pipes, RPC
6
Presentation
Data Translation; Compression and Encryption
Encoded User Data
Application data representations
SSL; Shells and Redirectors; MIME
7
Application
User Application Services
User Data
Application data
DNS; NFS; BOOTP; DHCP; SNMP; RMON; FTP; TFTP; SMTP; POP3; IMAP; NNTP; HTTP; Telnet
Group
#
Layer Name
Key Responsibilities
Data Type Handled
Scope
Common Protocols and Technologies
Lower Layers
1
Physical
Encoding and Signaling; Physical Data Transmission; Hardware Specifications; Topology and Design
Bits
Electrical or light signals sent between local devices
(Physical layers of most of the technologies listed for the data link layer)
2
Data Link
Logical Link Control; Media Access Control; Data Framing; Addressing; Error Detection and Handling; Defining Requirements of Physical Layer
Frames
Low-level data messages between local devices
IEEE 802.2 LLC, Ethernet Family; Token Ring; FDDI and CDDI; IEEE 802.11 (WLAN, Wi-Fi); HomePNA; HomeRF; ATM; SLIP and PPP
3
Network
Logical Addressing; Routing; Datagram Encapsulation; Fragmentation and Reassembly; Error Handling and Diagnostics
Datagrams / Packets
Messages between local or remote devices
IP; IPv6; IP NAT; IPsec; Mobile IP; ICMP; IPX; DLC; PLP; Routing protocols such as RIP and BGP
4
Transport
Process-Level Addressing; Multiplexing/Demultiplexing; Connections; Segmentation and Reassembly;
Acknowledgments and Retransmissions;
Flow Control
Datagrams / Segments
Communication between software processes
TCP and UDP; SPX; NetBEUI/NBF
Upper Layers
5
Session
Session Establishment, Management and Termination
Sessions
Sessions between local or remote devices
NetBIOS, Sockets, Named Pipes, RPC
6
Presentation
Data Translation; Compression and Encryption
Encoded User Data
Application data representations
SSL; Shells and Redirectors; MIME
7
Application
User Application Services
User Data
Application data
DNS; NFS; BOOTP; DHCP; SNMP; RMON; FTP; TFTP; SMTP; POP3; IMAP; NNTP; HTTP; Telnet