OSI 7 Layers

μ˜μ–΄λ‘œ 된 뢀뢄은 μ²˜μŒμ— κ³΅λΆ€ν•œ λ‚΄μš© & ν•œκΈ€λ‘œ 된 뢀뢄은 책보며 λ‹€μ‹œ κ³΅λΆ€ν•œ λ‚΄μš©

Reference: [μ±…] IT μ—”μ§€λ‹ˆμ–΄λ₯Ό μœ„ν•œ λ„€νŠΈμ›Œν¬ μž…λ¬Έ

Before getting started

  • κ³Όκ±°μ—λŠ” ν†΅μ‹ μš© κ·œμ•½μ΄ ν‘œμ€€ν™”λ˜μ§€ μ•Šμ•„μ„œ ν˜Έν™˜λ˜μ§€ μ•ŠλŠ” systemμ΄λ‚˜ application이 λ§Žμ•˜κ³  톡신이 λΆˆκ°€λŠ₯ ν–ˆμŒ

    • 이것을 ν•˜λ‚˜μ˜ κ·œμ•½μœΌλ‘œ 톡합 ν•˜λ €λŠ” λ…Έλ ₯이 ν˜„μž¬μ˜ OSI 7 Layers 둜 λ‚¨μ•„μžˆλ‹€!

  • OSI 7 Layersκ°€ network λ™μž‘μ„ λ‚˜λˆ„μ–΄ μ΄ν•΄ν•˜κ³  κ°œλ°œν•˜λŠ”λ° 도움이 λ˜λ―€λ‘œ main network reference model둜 ν™œμš©λ˜κ³  μžˆμ§€λ§Œ,

    • ν˜„μž¬ λŒ€λΆ€λΆ„μ˜ protocol은 TCP/IP protocol stack 기반으둜 λ˜μ–΄ μžˆλ‹€

What is OSI 7 Layers?

OSI 7 Layers

  • OSI (= Open Systems Interconnection) is a 7 layer architecture with each layer having specific functionality to perform.

  • All these 7 layers work collaboratively to transmit the data from one person to another across the globe.

OSI 7 Layers

OSI 7 LayersλŠ” κ³„μΈ΅μ˜ μ—­ν• κ³Ό λͺ©ν‘œμ— 따라 두 가지 κ³„μΈ΅μœΌλ‘œ λ‚˜λˆŒ 수 μžˆλ‹€.

1~4 계측

  • Lower Layer

  • Data Flow Layer

    • dataλ₯Ό μƒλŒ€λ°©μ—κ²Œ 잘 μ „λ‹¬ν•˜λŠ” 역할을 κ°–κ³  μžˆλ‹€

5~7 계측

  • Upper Layer

  • Application Layer

    • dataλ₯Ό λ§Œλ“œλŠ” 역할을 ν•˜λŠ” 뢀뢄이닀

  • application 개발자

    • data flow layerλ₯Ό κ³ λ €ν•˜μ§€ μ•Šκ³  dataλ₯Ό ν‘œν˜„ν•˜λŠ” 데 μ΄ˆμ μ„ λ§žμΆ˜λ‹€

    • Top-down ν˜•μ‹μœΌλ‘œ networkλ₯Ό 바라본닀

  • network engineer

    • application layerλŠ” application κ°œλ°œμžλ“€μ΄ κ³ λ €ν•΄μ•Ό ν•  μ˜μ—­μ΄λ―€λ‘œ network engineerλŠ” 이 뢀뢄에 λŒ€ν•΄ 일반적으둜 μ‹¬κ°ν•˜κ²Œ κ³ λ―Όν•˜μ§€ μ•ŠλŠ”λ‹€

    • Bottom-up ν˜•μ‹μœΌλ‘œ networkλ₯Ό 바라본닀

Details

1. Physical Layer (Layer 1)

  • The lowest layer of the OSI reference model is the physical layer.

  • It is responsible for the actual physical connection between the devices.

  • The physical layer contains information in the form of bits.

    • It is responsible for transmitting individual bits from one node to the next.

    • When receiving data, this layer will get the signal received and convert it into 0s and 1s and send them to the Data Link layer, which will put the frame back together.

img

  • 물리적 μ—°κ²°κ³Ό κ΄€λ ¨λœ 정보λ₯Ό μ •μ˜

  • 주둜 μ „κΈ° μ‹ ν˜Έ λ₯Ό μ „λ‹¬ν•˜λŠ”λ° 초점이 λ§žμΆ”μ–΄μ Έ 있음

    • λ“€μ–΄μ˜¨ μ „κΈ° μ‹ ν˜Έλ₯Ό κ·ΈλŒ€λ‘œ 잘 μ „λ‹¬ν•˜λŠ” 것이 λͺ©μ μ΄λ―€λ‘œ μ „κΈ° μ‹ ν˜Έκ°€ 1계측 μž₯λΉ„ 에 λ“€μ–΄μ˜€λ©΄ 이 μ „κΈ° μ‹ ν˜Έλ₯Ό μž¬μƒμ„±ν•˜μ—¬ 내보낸닀

  • 1계측 μž₯λΉ„λŠ” μ£Όμ†Œμ˜ κ°œλ…μ΄ μ—†λ‹€!

    • μ‹ ν˜Έκ°€ λ“€μ–΄μ˜¨ portλ₯Ό μ œμ™Έν•˜κ³  λͺ¨λ“  port에 같은 μ „κΈ° μ‹ ν˜Έλ₯Ό μ „μ†‘ν•œλ‹€

      • 즉, μΆœλ°œμ§€μ™€ λͺ©μ μ§€λ₯Ό ꡬ뢄 ν•  수 μ—†λ‹€

  • The data link layer is responsible for the node to node delivery of the message.

  • The main function of this layer is to make sure data transfer is error-free from one node to another, over the physical layer.

  • When a packet arrives in a network, it is the responsibility of DLL to transmit it to the Host using its MAC address.

  • Data Link Layer is divided into two sub layers :

    1. Logical Link Control (LLC)

    2. Media Access Control (MAC)

  • The packet received from Network layer is further divided into frames depending on the frame size of NIC(Network Interface Card).

  • DLL encapsulates Sender and Receiver’s MAC address in the header.

  • The Receiver’s MAC address is obtained by placing an ARP(Address Resolution Protocol) request onto the wire asking β€œWho has that IP address?” and the destination host will reply with its MAC address. img

  • μ „κΈ° μ‹ ν˜Έλ₯Ό λͺ¨μ•„ μš°λ¦¬κ°€ μ•Œμ•„λ³Ό 수 μžˆλŠ” data ν˜•νƒœλ‘œ μ²˜λ¦¬ν•œλ‹€

  • 1κ³„μΈ΅κ³ΌλŠ” λ‹€λ₯΄κ²Œ μ „κΈ° μ‹ ν˜Έλ₯Ό μ •ν™•νžˆ μ „λ‹¬ν•˜κΈ° λ³΄λ‹€λŠ” μ£Όμ†Œ 정보λ₯Ό μ •μ˜ν•˜κ³  μ •ν™•ν•œ μ£Όμ†Œλ‘œ ν†΅μ‹ ν•˜λŠ”λ° 초점이 λ§žμΆ”μ–΄μ Έ μžˆλ‹€

  • μΆœλ°œμ§€ 와 도착지 μ£Όμ†Œλ₯Ό ν™•μΈν•˜κ³  λ‚΄κ²Œ 보낸 것이 λ§žλŠ”μ§€ or λ‚΄κ°€ μ²˜λ¦¬ν•΄μ•Ό ν•˜λŠ”μ§€μ— λŒ€ν•΄ κ²€μ‚¬ν•œ 후에 data 처리λ₯Ό μˆ˜ν–‰ν•œλ‹€

  • 2κ³„μΈ΅μ—μ„œλŠ” μ£Όμ†Œ 체계 κ°€ μƒκΈ°λ©΄μ„œ μ—¬λŸ¬ 톡신이 ν•œκΊΌλ²ˆμ— μ΄λ£¨μ–΄μ§€λŠ” 것을 κ΅¬λΆ„ν•˜κΈ° μœ„ν•œ κΈ°λŠ₯이 주둜 μ •μ˜λœλ‹€

  • μ „κΈ° μ‹ ν˜Έλ₯Ό λͺ¨μ•„ data ν˜•νƒœλ‘œ μ²˜λ¦¬ν•˜λ―€λ‘œ data에 λŒ€ν•œ errorλ₯Ό νƒμ§€ν•˜κ±°λ‚˜ κ³ μΉ˜λŠ” 역할을 μˆ˜ν–‰ν•  수 μžˆλ‹€

    • Ethernet 기반 network의 2κ³„μΈ΅μ—μ„œλŠ” errorλ₯Ό νƒμ§€ν•˜λŠ” μ—­ν• λ§Œ μˆ˜ν–‰ν•œλ‹€

  • μ£Όμ†Œ 체계가 μƒκΈ΄λ‹€λŠ” 것은 ν•œ λͺ…κ³Ό ν†΅μ‹ ν•˜λŠ” 것이 μ•„λ‹ˆλΌ λ™μ‹œμ— μ—¬λŸ¬ λͺ…κ³Ό 톡신할 수 μžˆλ‹€λŠ” κ²ƒμ΄λ―€λ‘œ λ¬΄μž‘μ • dataλ₯Ό λ˜μ§€λŠ” 것이 μ•„λ‹ˆλΌ λ°›λŠ” μ‚¬λžŒμ΄ ν˜„μž¬ dataλ₯Ό 받을 수 μžˆλŠ”μ§€ 확인 ν•˜λŠ” μž‘μ—…λΆ€ν„° ν•΄μ•Ό ν•œλ‹€

    • 이 역할을 Flow Control 이라고 λΆ€λ₯Έλ‹€

      • Flow Control

        1. μ„œλ²„μ—μ„œ μŠ€μœ„μΉ˜λ‘œ data 전솑

        2. μŠ€μœ„μΉ˜ 혼작 상황 λ°œμƒ. μŠ€μœ„μΉ˜λŠ” μ„œλ²„λ‘œ Pause frame 전솑

        3. μ„œλ²„λŠ” Pause frame μˆ˜μ‹  수 λŒ€κΈ°

  • 2κ³„μΈ΅μ˜ network ꡬ성 μš”μ†ŒλŠ” Network Interface Card와 Switch이닀

  • 2κ³„μΈ΅μ˜ κ°€μž₯ μ€‘μš”ν•œ νŠΉμ§•μ€ MAC μ£Όμ†ŒλΌλŠ” μ£Όμ†Œ 체계가 μžˆλ‹€λŠ” 것이닀

    • 2κ³„μΈ΅μ—μ„œ λ™μž‘ν•˜λŠ” Network Interface Card와 Switch λͺ¨λ‘ MAC μ£Όμ†Œλ₯Ό 이해할 수 있고, SwitchλŠ” MAC μ£Όμ†Œλ₯Ό 보고 톡신해야 ν•  portλ₯Ό 지정해 λ‚΄λ³΄λ‚΄λŠ” λŠ₯λ ₯이 μžˆλ‹€

      • Network Interface Card λ™μž‘ 방식

        1. μ „κΈ° μ‹ ν˜Έλ₯Ό data ν˜•νƒœλ‘œ λ§Œλ“ λ‹€

        2. λͺ©μ μ§€ MAC μ£Όμ†Œμ™€ μΆœλ°œμ§€ MAC μ£Όμ†Œλ₯Ό ν™•μΈν•œλ‹€

        3. Network Interface Card의 MAC μ£Όμ†Œλ₯Ό ν™•μΈν•œλ‹€

        4. λͺ©μ μ§€ MAC μ£Όμ†Œμ™€ Network Interface Cardκ°€ κ°–κ³  μžˆλŠ” MAC μ£Όμ†Œκ°€ 맞으면 dataλ₯Ό μ²˜λ¦¬ν•˜κ³ , λ‹€λ₯΄λ©΄ dataλ₯Ό νκΈ°ν•œλ‹€

      • Switch λ™μž‘ 방식

        • SwtichλŠ” 단말이 μ–΄λ–€ MAC μ£Όμ†ŒμΈμ§€, μ—°κ²°λœ portλŠ” μ–΄λŠ 것인지 μ£Όμ†Œ μŠ΅λ“ (Address learning) κ³Όμ •μ—μ„œ μ•Œ 수 μžˆλ‹€

          • 이 dataλ₯Ό 기반으둜 단말듀이 톡신할 λ•Œ portλ₯Ό 적절히 filtering ν•˜κ³ , μ •ν™•ν•œ port둜 forwarding ν•΄μ€€λ‹€

        • Switch의 μ μ ˆν•œ filteringκ³Ό forwarding κΈ°λŠ₯으둜 톡신이 ν•„μš”ν•œ port만 μ‚¬μš©ν•˜κ³ , network 전체에 λΆˆν•„μš”ν•œ μ²˜λ¦¬κ°€ κ°μ†Œν•˜λ©΄μ„œ

          • Ethernet network νš¨μœ¨μ„±μ΄ 크게 ν–₯μƒλ˜μ—ˆκ³ ,

          • Ethernet 기반 networkκ°€ κΈ‰μ¦ν•˜λŠ” 계기가 λ˜μ—ˆλ‹€!

3. Network Layer (Layer 3)

  • Network layer works for the transmission of data from one host to the other located in different networks.

  • It also takes care of packet routing i.e. selection of the shortest path to transmit the packet, from the number of routes available.

  • The sender & receiver’s IP address are placed in the header by the network layer.

  • The functions of the Network layer are :

    1. Routing

      • The network layer protocols determine which route is suitable from source to destination.

      • This function of network layer is known as routing.

    2. Logical Addressing

      • In order to identify each device on internetwork uniquely, network layer defines an addressing scheme.

      • The sender & receiver’s IP address are placed in the header by network layer.

      • Such an address distinguishes each device uniquely and universally.

  • Segment in Network layer is referred as Packet. img

  • Network layer is implemented by networking devices such as routers

  • 3κ³„μΈ΅μ—μ„œλŠ” IP μ£Όμ†Œμ™€ 같은 논리적인 μ£Όμ†Œκ°€ μ •μ˜λœλ‹€

    • data 톡신을 ν•  λ•Œμ—λŠ” 두 가지 μ£Όμ†Œκ°€ μ‚¬μš©λœλ‹€

      1. 2κ³„μΈ΅μ˜ 물리적인 MAC μ£Όμ†Œ

      2. 3κ³„μΈ΅μ˜ 논리적인 IP μ£Όμ†Œ

    • MAC μ£Όμ†Œμ™€ 달리 IP μ£Όμ†ŒλŠ” μ‚¬μš©μžκ°€ ν™˜κ²½μ— 맞게 λ³€κ²½ν•΄ μ‚¬μš©ν•  수 μžˆλ‹€

    • IPμ£Όμ†ŒλŠ” λ„€νŠΈμ›Œν¬ μ£Όμ†Œ λΆ€λΆ„κ³Ό 호슀트 μ£Όμ†Œ λΆ€λΆ„μœΌλ‘œ λ‚˜λ‰œλ‹€

      • 3계측을 이해할 수 μžˆλŠ” μž₯λΉ„λ‚˜ 단말은 λ„€νŠΈμ›Œν¬ μ£Όμ†Œ 정보λ₯Ό μ΄μš©ν•΄μ„œ

        1. μžμ‹ μ΄ μ†ν•œ λ„€νŠΈμ›Œν¬μ™€ 원격지 λ„€νŠΈμ›Œν¬λ₯Ό ꡬ뢄할 수 있고

        2. 원격지 λ„€νŠΈμ›Œν¬λ₯Ό κ°€λ €λ©΄ μ–΄λ””λ‘œ κ°€μ•Όν•˜λŠ”μ§€ 경둜λ₯Ό 지정할 수 μžˆλ‹€

  • 3κ³„μΈ΅μ—μ„œ λ™μž‘ν•˜λŠ” μž₯λΉ„λŠ” Routerλ‹€

    • RouterλŠ” 3κ³„μΈ΅μ—μ„œ μ •μ˜ν•œ IP μ£Όμ†Œλ₯Ό 이해할 수 μžˆλ‹€

    • RouterλŠ” IP μ£Όμ†Œλ₯Ό μ‚¬μš©ν•΄ 졜적의 경둜λ₯Ό μ°Ύμ•„μ£Όκ³ , ν•΄λ‹Ή 경둜둜 packet을 μ „μ†‘ν•˜λŠ” 역할을 ν•œλ‹€

4. Transport Layer (Layer 4)

  • Transport layer provides services to application layer and takes services from network layer.

  • The data in the transport layer is referred to as Segments.

    • It is responsible for the End to End Delivery of the complete message.

  • The transport layer also provides the acknowledgement of the successful data transmission and re-transmits the data if an error is found.

  • Transport layer is operated by the Operating System.

    • It is a part of the OS and communicates with the Application Layer (Layer 7) by making system calls.

  • Transport Layer is called as Heart of OSI model.

  • 4계측은 1~3κ³„μΈ΅κ³ΌλŠ” λ‹€λ₯Έ 역할을 ν•œλ‹€

    • ν•˜μœ„ 계측 (Layer 1~4)은 dataλ₯Ό μͺΌκ°œ 정보λ₯Ό λΆ™μ—¬ λͺ©μ μ§€κΉŒμ§€ 잘 μ „λ‹¬ν•˜λŠ” 역할을 ν•˜λŠ”λ°,

      • 1~3계측은 μ‹ ν˜Έμ™€ dataλ₯Ό μ˜¬λ°”λ₯Έ μœ„μΉ˜λ‘œ 보내고, μ‹€μ œ μ‹ ν˜Έλ₯Ό 잘 λ§Œλ“€μ–΄ λ³΄λ‚΄λŠ”λ° μ§‘μ€‘ν•œλ‹€

      • 반면 4계측은 μ‹€μ œλ‘œ ν•΄λ‹Ή data듀이 μ •μƒμ μœΌλ‘œ 잘 보내지도둝 ν™•μΈν•˜λŠ” 역할을 ν•œλ‹€

  • Packet network λŠ” dataλ₯Ό λΆ„ν• ν•΄ packet에 싀어보내닀 λ³΄λ‹ˆ 쀑간에 packet이 μœ μ‹€λ˜κ±°λ‚˜ μˆœμ„œκ°€ λ’€λ°”λ€ŒλŠ” κ²½μš°κ°€ 생길 수 μžˆλ‹€

  • 이럴 λ•Œ λ°”λ‘œ μž‘μ•„μ£ΌλŠ” 역할을 4κ³„μΈ΅μ—μ„œ λ‹΄λ‹Ήν•œλ‹€

    • 4κ³„μΈ΅μ—μ„œ packet을 λΆ„ν• ν•  λ•Œ packet header에 λ³΄λ‚΄λŠ” μˆœμ„œμ™€ λ°›λŠ” μˆœμ„œλ₯Ό 적어 ν†΅μ‹ ν•˜λ―€λ‘œ

      • packet이 μœ μ‹€λ˜λ©΄ μž¬μ „μ†‘μ„ μš”μ²­ν•  수 있고,

      • μˆœμ„œκ°€ λ’€λ°”λ€Œλ”λΌλ„ λ°”λ‘œ μž‘μ„ 수 μžˆλ‹€

    • Packet에 λ³΄λ‚΄λŠ” μˆœμ„œλ₯Ό λͺ…μ‹œν•œ 것이 μ‹œν€€μŠ€ 번호(Sequence Number)이고,

    • Packet에 λ°›λŠ” μˆœμ„œλ₯Ό λͺ…μ‹œν•œ 것이 ACK 번호(Acknowledgement Number)이닀

    • μž₯치 λ‚΄μ˜ λ§Žμ€ application을 ꡬ뢄할 수 μžˆλ„λ‘ 포트 번호(Port Number)λ₯Ό μ‚¬μš©ν•΄ μƒμœ„ application을 κ΅¬λΆ„ν•œλ‹€

  • 4κ³„μΈ΅μ—μ„œ 동μž₯ν•˜λŠ” μž₯λΉ„λŠ” Load Balancer와 방화벽이닀

    • 이 μž₯비듀은 4κ³„μΈ΅μ—μ„œ λ³Ό 수 μžˆλŠ” application κ΅¬λΆ„μž (Port Number)와 Sequence, ASK number 정보λ₯Ό μ΄μš©ν•΄μ„œ

      • λΆ€ν•˜λ₯Ό λΆ„μ‚°ν•˜κ±°λ‚˜ λ³΄μ•ˆ 정책을 μˆ˜λ¦½ν•΄ packet을 톡과, μ°¨λ‹¨ν•˜λŠ” κΈ°λŠ₯을 μˆ˜ν–‰ν•œλ‹€

5. Session Layer (Layer 5)

  • The Session layer is responsible for establishment of connection, maintenance of sessions, authentication and also ensures security.

  • The functions of the session layer are :

    1. Session establishment, maintenance and termination

      • The layer allows the two processes to establish, use and terminate a connection.

    2. Synchronization

      • This layer allows a process to add checkpoints which are considered as synchronization points into the data.

      • These synchronization point help to identify the error so that the data is re-synchronized properly, and ends of the messages are not cut prematurely and data loss is avoided.

    3. Dialog Controller

      • The session layer allows two systems to start communication with each other in half-duplex or full-duplex.

  • 5계측인 **μ„Έμ…˜ 계측(Session Layer)**은 μ–‘ λλ‹¨μ˜ μ‘μš© ν”„λ‘œμ„ΈμŠ€κ°€

    • 연결을 μ„±λ¦½ν•˜λ„λ‘ 도와주고,

    • 연결이 μ•ˆμ •μ μœΌλ‘œ μœ μ§€λ˜λ„λ‘ κ΄€λ¦¬ν•˜κ³ ,

    • μž‘μ—… μ™„λ£Œ ν›„μ—λŠ” 연결을 λŠλŠ” 역할을 ν•œλ‹€

  • Session을 κ΄€λ¦¬ν•˜λŠ” 것이 μ£Ό 역할인 session layerλŠ” TCP/IP session을 λ§Œλ“€κ³  μ—†μ• λŠ” 역할을 ν•œλ‹€

  • Error둜 μ€‘λ‹¨λœ 톡신에 λŒ€ν•œ 볡ꡬ와 μž¬μ „μ†‘λ„ μˆ˜ν–‰ν•œλ‹€

6. Presentation Layer (Layer 6)

  • Presentation layer is also called the Translation layer.

  • The data from the application layer is extracted here and manipulated as per the required format to transmit over the network.

  • The functions of the presentation layer are :

    1. Translation

      • For example, ASCII to EBCDIC.

    2. Encryption/ Decryption

      • Data encryption translates the data into another form or code.

    3. Compression

      • Reduces the number of bits that need to be transmitted on the network.

  • 6계측인 presentation layerλŠ” ν‘œν˜„ 방식이 λ‹€λ₯Έ applicationμ΄λ‚˜ system κ°„μ˜ 톡신을 돕기 μœ„ν•΄ ν•˜λ‚˜μ˜ ν†΅μΌλœ ꡬ문 ν˜•μ‹μœΌλ‘œ λ³€ν™˜μ‹œν‚€λŠ” κΈ°λŠ₯을 μˆ˜ν–‰ν•œλ‹€

    • μΌμ’…μ˜ λ²ˆμ—­κΈ°λ‚˜ λ³€ν™˜κΈ° 역할을 μˆ˜ν–‰ν•˜λŠ” 계측이고,

    • μ΄λŸ¬ν•œ κΈ°λŠ₯은 μ‚¬μš©μž system의 μ‘μš© κ³„μΈ΅μ—μ„œ data의 ν˜•μ‹μƒμ˜ 차이λ₯Ό λ‹€λ£¨λŠ” 뢀담을 λœμ–΄μ€€λ‹€

    • MIME encodingμ΄λ‚˜ μ•”ν˜Έν™”, μ••μΆ•, μ½”λ“œ λ³€ν™˜κ³Ό 같은 λ™μž‘μ΄ 이 κ³„μΈ΅μ—μ„œ 이루어진닀

7. Application Layer (Layer 7)

  • At the very top of the OSI Reference Model stack of layers, we find Application layer which is implemented by the network applications.

  • These applications produce the data, which has to be transferred over the network.

  • This layer also serves as a window for the application services to access the network and for displaying the received information to the user.

    • Ex: Application – Browsers, Skype Messenger etc.

  • Application Layer is also called as Desktop Layer.

  • OSI 7 Layers의 μ΅œμƒμœ„ 7계측인 application layerλŠ” application processλ₯Ό μ •μ˜ν•˜κ³  application serviceλ₯Ό μˆ˜ν–‰ν•œλ‹€

    • Network software의 UI λΆ€λΆ„μ΄λ‚˜ μ‚¬μš©μž I/O 뢀뢄을 μ •μ˜ν•˜λŠ” 것이 application layer의 역할이닀

    • application layer의 protocol은 μ—„μ²­λ‚˜κ²Œ λ§Žμ€ μ’…λ₯˜κ°€ μžˆμ§€λ§Œ λŒ€ν‘œμ μΈ Protocolλ‘œλŠ” FTP, SMTP, HTTP TELNET이 μžˆλ‹€

Summary

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계측별 μ£Όμš” ν”„λ‘œν† μ½œ 및 μž₯λΉ„

Layer
Protocol
μž₯λΉ„

Application Layer

HTTP, SMP, SMTP, STUN, TFTP, TELNET

ADC, NGFW, WAF

Presentation Layer

TLS, AFP, SSH

Session Layer

L2TP, PPTP, NFS, RPC, RTCP, SIP, SSH

Transport Layer

TCP, UDP, SCTP, DCCP, AH, AEP

LB, Firewall

Network Layer

ARP, IPv4, IPv6, NAT, IPSec, VRRP, Routing protocol

Router, L3 Switch

Datalink Layer

IEEE 802.2, FDDI

Switch, Bridge, NIC

Physical Layer

RS-232, RS-449, V.35, S λ“±μ˜ cable

Cable, Hub, TAP

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