Which Osi Layer Provides File Transfer Services

The presentation layer is responsible for the formatting and delivery of information to the application layer for further processing or display. It relieves the application layer of concern regarding syntactical differences in data representation within the end-user systems. An example of a presentation service would be the conversion of an EBCDIC-coded text computer file to an. Core of TCP/IP Stack provides communication services directly to the application processes that are running on network hosts. Application Layer Provides applications for file transfer, Network Troubleshooting, and Internet activities.

An application layer is an abstraction layer that specifies the shared communications protocols and interface methods used by hosts in a communications network.^[1]The application layer abstraction is used in both of the standard models of computer networking: the Internet Protocol Suite (TCP/IP) and the OSI model.^[2] Although both models use the same term for their respective highest level layer, the detailed definitions and purposes are different.^[3]

In TCP/IP, the application layer contains the communications protocols and interface methods used in process-to-process communications across an Internet Protocol (IP) computer network.^[4]The application layer only standardizes communication and depends upon the underlying transport layer protocols to establish host-to-host data transfer channels and manage the data exchange in a client-server or peer-to-peer networking model.^[5] Though the TCP/IP application layer does not describe specific rules or data formats that applications must consider when communicating, the original specification (in RFC1123) does rely on and recommend the robustness principle for application design.^[6][7]

In the OSI model, the definition of the application layer is narrower in scope.^[8] The OSI model defines the application layer as the user interface responsible for displaying received information to the user.^[9] In contrast, the Internet Protocol Suite does not concern itself with such detail. OSI also explicitly distinguishes additional functionality below the application layer, but above the transport layer at two additional levels: the session layer, and the presentation layer. George washington high school chicago drivers ed. OSI specifies a strict modular separation of functionality at these layers and provides protocol implementations for each layer.^[9]

• 1Protocols

Protocols[edit]

(Session Layer under OSI model) The IETF definition document for the application layer in the Internet Protocol Suite is RFC 1123. It provided an initial set of protocols that covered the major aspects of functionality of the early Internet.^[6]

• Remote login to hosts: Telnet
• File transfer: File Transfer Protocol (FTP), Trivial File Transfer Protocol (TFTP)
• Electronic mail transport: Simple Mail Transfer Protocol (SMTP)
• Networking support: Domain Name System (DNS)
• Host initialization: BOOTP
• Remote host management: Simple Network Management Protocol (SNMP), Common Management Information Protocol over TCP (CMOT)

Examples[edit]

• 9P, Plan 9 from Bell Labs distributed file system protocol
• AFP, Apple Filing Protocol
• APPC, Advanced Program-to-Program Communication
• AMQP, Advanced Message Queuing Protocol
• BEEP, Block Extensible Exchange Protocol
• CFDP, Coherent File Distribution Protocol
• CoAP, Constrained Application Protocol
• DDS, Data Distribution Service
• ENRP, Endpoint Handlespace Redundancy Protocol
• FastTrack (KaZaa, Grokster, iMesh)
• Finger, User Information Protocol
• FTAM, File Transfer Access and Management
• Gopher, Gopher protocol
• HL7, Health Level Seven
• HTTP, Hypertext Transfer Protocol
• H.323, Packet-Based Multimedia Communications System
• IMAP, Internet Message Access Protocol
• IRCP, Internet Relay Chat Protocol
• IPFS, InterPlanetary File System
• LDAP, Lightweight Directory Access Protocol
• LPD, Line Printer Daemon Protocol
• MIME (S-MIME), Multipurpose Internet Mail Extensions and Secure MIME
• MQTT Protocol
• NFS, Network File System
• NIS, Network Information Service
• NNTP, Network News Transfer Protocol
• NTCIP, National Transportation Communications for Intelligent Transportation System Protocol
• NTP, Network Time Protocol
• OSCAR, AOL Instant Messenger Protocol
• POP, Post Office Protocol
• PNRP, Peer Name Resolution Protocol
• RDP, Remote Desktop Protocol
• RELP, Reliable Event Logging Protocol
• RFP, Remote Framebuffer Protocol
• Rlogin, Remote Login in UNIX Systems
• RPC, Remote Procedure Call
• RTMP, Real Time Messaging Protocol
• RTP, Real-time Transport Protocol
• RTPS, Real Time Publish Subscribe
• RTSP, Real Time Streaming Protocol
• SAP, Session Announcement Protocol
• SDP, Session Description Protocol
• SIP, Session Initiation Protocol
• SLP, Service Location Protocol
• SMB, Server Message Block
• SMTP, Simple Mail Transfer Protocol
• SNTP, Simple Network Time Protocol
• SSH, Secure Shell
• SSMS, Secure SMS Messaging Protocol
• TCAP, Transaction Capabilities Application Part
• TDS, Tabular Data Stream
• TSP, Time Stamp Protocol
• VTP, Virtual Terminal Protocol
• Whois (and RWhois), Remote Directory Access Protocol
• X.400, Message Handling Service Protocol
• X.500, Directory Access Protocol (DAP)
• XMPP, Extensible Messaging and Presence Protocol

• DNS, Domain Name Services

References[edit]

1. ^'Application Layer Layer 7'. The OSI-Model. Retrieved November 5, 2019.
2. ^'Four Layers of TCP/IP model, Comparison and Difference between TCP/IP and OSI models'. www.omnisecu.com. Retrieved November 5, 2019.
3. ^'What is the difference between TCP/IP and IP protocol?'. SearchNetworking. Retrieved November 5, 2019.
4. ^'What is the difference between TCP/IP and IP protocol?'. SearchNetworking. Retrieved November 5, 2019.
5. ^SEO, Bradley Mitchell An MIT graduate who brings years of technical experience to articles on; computers; Networking, Wireless. 'What Is Transmission Control Protocol/Internet Protocol (TCP/IP)?'. Lifewire. Retrieved November 5, 2019.
6. ^ ^abRobert Braden, ed. (October 1989). 'RFC 1123: Requirements for Internet Hosts – Application and Support'. Network Working Group of the IETF.
7. ^'What is the Application Layer?'. www.tutorialspoint.com. Retrieved November 5, 2019.
8. ^Shaw, Keith (October 22, 2018). 'The OSI model explained: How to understand (and remember) the 7 layer network model'. Network World. Retrieved November 5, 2019.
9. ^ ^ab'What Is The OSI Model?'. CloudFlare. 2019. Retrieved November 4, 2019.

External links[edit]

In the seven-layer OSI model of computer networking, the presentation layer is layer 6 and serves as the data translator for the network.^[1][2] It is sometimes called the syntax layer.^[3]

• 3Sublayers

Description[edit]

The presentation layer is responsible for the formatting and delivery of information to the application layer for further processing or display.^[4] It relieves the application layer of concern regarding syntactical differences in data representation within the end-user systems. An example of a presentation service would be the conversion of an EBCDIC-coded text computer file to an ASCII-coded file.

The presentation layer is the lowest layer at which application programmers consider data structure and presentation, instead of simply sending data in the form of datagrams or packets between hosts. This layer deals with issues of string representation - whether they use the Pascal method (an integer length field followed by the specified amount of bytes) or the C/C++ method (null-terminated strings, e.g. 'thisisastring0'). The idea is that the application layer should be able to point at the data to be moved, and the presentation layer will deal with the rest.

Serialization of complex data structures into flat byte-strings (using mechanisms such as TLV or XML) can be thought of as the key functionality of the presentation layer.

Encryption is typically done at this level too, although it can be done on the application, session, transport, or network layers, each having its own advantages and disadvantages.^[1]Decryption is also handled at the presentation layer. For example, when logging on to bank account sites the presentation layer will decrypt the data as it is received.^[1] Another example is representing structure, which is normally standardized at this level, often by using XML. As well as simple pieces of data, like strings, more complicated things are standardized in this layer. Two common examples are 'objects' in object-oriented programming, and the exact way that streaming video is transmitted.

In many widely used applications and protocols, no distinction is made between the presentation and application layers. For example, HyperText Transfer Protocol (HTTP), generally regarded as an application-layer protocol, has presentation-layer aspects such as the ability to identify character encoding for proper conversion, which is then done in the application layer.

Within the service layering semantics of the OSI network architecture, the presentation layer responds to service requests from the application layer and issues service requests to the session layer.

In the OSI model: the presentation layer ensures the information that the application layer of one system sends out is readable by the application layer of another system. For example, a PC program communicates with another computer, one using extended binary coded decimal interchange code (EBCDIC) and the other using ASCII to represent the same characters. If necessary, the presentation layer might be able to translate between multiple data formats by using a common format.

Services[edit]

• Data conversion^[2]
• Character code translation^[2]
• Compression^[2]
• Encryption and Decryption^[2]

Sublayers[edit]

The presentation layer can be composed of two sublayers: common application service element (CASE) and specific application service element (SASE).^[5]

CASE[edit]

The common application service element sublayer provides services for the application layer and request services from the session layer.It provides support for common application services, such as: One piece pirate warriors 3 pc download utorrent.

• ACSE (Association Control Service Element)^[5]
• ROSE (Remote Operation Service Element)
• CCR (Commitment Concurrency and Recovery)
• RTSE (Reliable Transfer Service Element)

SASE[edit]

The specific application service element sublayer provides application specific services (protocols), such as

• FTAM (File Transfer, Access and Manager)
• VT (Virtual Terminal)
• MOTIS (Message Oriented Text Interchange Standard)
• CMIP (Common Management Information Protocol)
• JTM (Job Transfer and Manipulation) a former OSI standard
• MMS (Manufacturing Messaging Service)
• RDA (Remote Database Access)
• DTP (Distributed Transaction Processing)

Protocols[edit]

Other protocols sometimes considered at this level (though perhaps not strictly adhering to the OSI model) include:

• Apple Filing Protocol (AFP)
• Independent Computing Architecture (ICA), the Citrix system core protocol
• Lightweight Presentation Protocol (LPP)
• NetWare Core Protocol (NCP)
• Network Data Representation (NDR)
• Telnet (a remote terminal access protocol)
• Tox, The Tox protocol is sometimes regarded as part of both the presentation and application layer
• eXternal Data Representation (XDR)
• X.25 Packet Assembler/Disassembler Protocol (PAD)

References[edit]

1. ^ ^abcDean, Tamara (2010). Network+ Guide to Networks. Delmar. pp. 44–47.
2. ^ ^abcdeMicrosoft TechNet
3. ^Grigonis, Richard (2000). Computer telephony encyclopedia. CMP. p. 331.
4. ^http://www.linfo.org/presentation_layer.html Linux Information Project
5. ^ ^abHura, Gurdeep (2001). 'Application Layer'. Data and Computer Communications: Networking and Internetworking. CRC Press LLC. pp. 710–712.