User:Becha/InternetPlumbing/Layers
Comparing OSI & TCP / IP layers
Original borrowed from: https://en.wikipedia.org/wiki/OSI_model
TCP / IP Model | OSI Model | |||
---|---|---|---|---|
Layer | OSI Layer | Protocol data unit (PDU) | Function | Examples |
Application | 7. Application | Data | High-level APIs, including resource sharing, remote file access, directory services and virtual terminals | TLS, FTP, HTTP, HTTPS, SMTP, SSH, Telnet, BGP! |
6. Presentation | Translation of data between a networking service and an application; including character encoding, data compression and encryption/decryption | CSS, GIF, HTML, XML, JSON | ||
Transport | 5. Session | Managing communication sessions, i.e. continuous exchange of information in the form of multiple back-and-forth transmissions between two nodes | RPC, SCP, NFS, PAP, | |
4. Transport | Segment (TCP) / Datagram (UDP) | Reliable transmission of data segments between points on a network, including segmentation, acknowledgement and multiplexing | NBF, TCP, UDP | |
Network / Internet |
3. Network | Packet | Structuring and managing a multi-node network, including addressing, routing and traffic control | AppleTalk, ICMP, IPsec, IPv4, IPv6 |
Link layer |
2. Data link | Frame | Reliable transmission of data frames between two nodes connected by a physical layer | IEEE 802.2, L2TP, LLDP, MAC, PPP, ATM, MPLS |
1. Physical | Bit | Transmission and reception of raw bit streams over a physical medium | DOCSIS, DSL, Ethernet physical layer, ISDN, USB |
Cross-layer functions:
- ARP is used to translate IPv4 addresses (OSI layer 3) into Ethernet MAC addresses (OSI layer 2).
- Domain Name Service is an Application Layer service which is used to look up the IP address of a given domain name. Once a reply is received from the DNS server, it is then possible to form a Layer 3 connection to the third-party host.
- etc
Owners, Developers, Dangers, Mitigations, Alternatives
Layer | Example | Practically | Owner | Developed by | Vulnerabilities/Dangers | Securing | Alternatives | |
---|---|---|---|---|---|---|---|---|
10 | ||||||||
9 | ||||||||
8 | ||||||||
7 | ||||||||
6 | ||||||||
5 | ||||||||
4 | ||||||||
8 | ||||||||
3 | Network | Internet | ifconfig; 10.10.10.10, IPv6 | no-one: IP addresses are "leased"! (PI,PA,LIR,RIR,IANA,IETF) |
RIR PDP, IANA, IETF | hierarchy, run-out, incompatibility, market forces; surveillance | IPSec | Blockchain? |
2 | Data-link | Physical connections | Ethernet cables, WiFi, fibers, satellites, under-sea cables | Individuals, communities, ISP, "carriers", corporations, governments, | Hackers, commercial companies, governments | "ownership" models; hierarchy of server-client model; pollution & distraction of Earth; surveillance | commoning; shared infrastructure; development of sustainable technologies (?!), recycling; awareness & activism | Community WiFi, Project Loon, Drones |
1 | Physical | HW - end user equipment | Computer, tablet, phone... | User | Commercial companies: Apple, Siemens, Samsung... | Un-ethical manufacturing, security backdoors, pollution caused by e-waste disposal, | Hard: | Open HW movement; fair-phone; DIY, Repair Cafes, fair-trade... |