Trivial File Transfer Protocol. It supports 5 types of packets:
2 bytes Opcode, n bytes Filename, 1 byte 0, n Bytes Mode, 1 byte 0
- WRQ (same as RRQ)
2 bytes Opcode, 2 bytes Block Number, 0-512 bytes Data
2 bytes Opcode, 2 bytes Block Number
2 bytes Opcode, 2 bytes Error Code, n bytes ErrMsg, 1 byte 0
Provides access to the OSI environment for users and also provides distributed information services
Provides independence to the application processes from differences in data representation (syntax)
Provides the control structure for communication between applications; establishes, manages, and terminates connections (sessions) between cooperating applications.
Provides reliable, transparent transfer of data between end points; provides end-to-end error recovery and flow control
Provides upper layers with independence from the data transmission and switching technologies used to connect systems; responsible for establishing, maintaining, and terminating connections.
2. Data Link
Provides for the reliable transfer of information across the physical link; sends blocks (frames) with the necessary synchronization, error control, and flow control
Concerned with transmission of unstructured bit stream over physical medium; deals with the mechanical, electrical, functional, and procedural characteristics to access the physical medium.
3rd EditionCharles E. Leiserson, Clifford Stein, Ronald L. Rivest, Thomas H. Cormen 5th EditionDavid A. Patterson, John L. Hennessy 5th EditionDavid A. Patterson, John L. Hennessy 8th EditionJohn Buck, William Hayt