All 24 OSI Model flashcards. Free.
The whole deck, not a sample — OSI Model is 24 cards, which is no longer than the 30 we give away on every deck, so there is nothing left to charge for. 11 pages, US Letter, black and white. Grades 9–12.
No account, no email, no card details.
11 pages, and the backs are already right
Every front sheet is followed by its own back sheet with the rows reversed. Print double-sided, flip on the long edge, and answer number 7 is behind question number 7. Print a deck you built yourself, flip on the short edge, and every answer lands on the wrong card — which nobody finds out until sixty cards have been cut apart.
- 24 cards — counted out of the file, not rounded up
- Eight cards a sheet, with cut guides
- US Letter PDF, black and white, photocopier-friendly
- Print a set per student, every class, every year
24 cards — the model has exactly seven layers, so this deck covers each layer once, the devices and protocols usually placed at each, and the OSI-to-TCP/IP mapping. Padding it further would mean repeating the same seven facts.
Every card here is cited to two independent sources
Two different organisations — not a standards body and a website reprinting it — and a script refuses the card if the two disagree, so the check runs on every card rather than on the ones somebody remembered to look at. A second specialist then re-verified this deck from sources of their own, without reading our citations first. A further 5,420 cards across 30 other decks were read end to end by a subject specialist instead, and we say which is which on every deck rather than averaging the two into one flattering word.
What 24 printed cards do that a screen does not
A phone deck is one card at a time. A printed deck is a pile you can split: the ones you know, the ones you nearly know, and the ones you keep missing. That third pile is the entire study session, and it is the thing a scrolling app hides from you.
- Print once, use all year. The licence covers a set per student, every class, every year.
- No device, no login, no data. Works in a cover lesson, on a bus, or at a kitchen table. Grades 9–12, filed under career, tech & modern.
- Change what you disagree with. Every card loads into the free maker on this site. Reword it, drop it, add your own, reprint.
Here are all 24 cards
Check them against your own textbook before you spend anything.
- OSI Layer 1
- Physical — mechanical, electrical, functional and procedural means to transmit bits over the medium
- OSI Layer 2
- Data Link — frames between adjacent nodes on a link; detects, and may correct, Physical Layer errors
- OSI Layer 3
- Network — routing and relaying; moves data between end systems across one or more subnetworks
- OSI Layer 4
- Transport — end-to-end transfer between end systems; routing and relaying do not happen here
- OSI Layer 5
- Session — organises and synchronises the dialogue between the two ends and manages their data exchange
- OSI Layer 6
- Presentation — data representation; picks the transfer syntax so the meaning survives the transfer
- OSI Layer 7
- Application — the only layer that serves application processes directly; no layer sits above it
- The seven OSI layers, Layer 1 up to Layer 7
- Physical, Data Link, Network, Transport, Session, Presentation, Application
- Mnemonic for the OSI layers bottom-up (1 → 7)
- Please Do Not Throw Sausage Pizza Away
- Mnemonic for the OSI layers top-down (7 → 1)
- All People Seem To Need Data Processing
- Which OSI layer does a hub or repeater work at?
- Layer 1, Physical — it regenerates the signal and reads no addresses
- Which OSI layer does an Ethernet switch or bridge work at?
- Layer 2, Data Link — it forwards frames by MAC address
- Which OSI layer does a router work at?
- Layer 3, Network — it forwards packets by logical (IP) address
- Which OSI layer is IP placed at?
- Layer 3, Network — logical addressing and routing
- Which OSI layer are TCP and UDP placed at?
- Layer 4, Transport — port numbers belong to this layer too
- Which OSI layer are HTTP, FTP, SMTP and DNS placed at?
- Layer 7, Application
- Which OSI layer is a MAC address used at?
- Layer 2, Data Link — the MAC sublayer of the Data Link Layer
- Which OSI layer handles compression and format translation?
- Layer 6, Presentation — it selects the transfer syntax both ends accept
- The two sublayers IEEE divides OSI Layer 2 into
- MAC (media access control) and LLC (logical link control)
- Everyday name for the Layer 2 protocol data unit
- Frame — ISO/IEC 7498-1 itself calls it a data-link-protocol-data-unit
- Everyday name for the Layer 3 protocol data unit
- Packet
- Everyday name for the Layer 4 protocol data unit
- Segment for TCP; a UDP one is called a datagram
- Is the TCP/IP model just another name for the OSI model?
- No — two separate models. RFC 1122 gives TCP/IP four layers: Link, Internet, Transport, Application
- How do the four TCP/IP layers line up with the seven OSI layers?
- Roughly Link ≈ OSI 1–2, Internet ≈ 3, Transport ≈ 4, Application ≈ 6–7 — RFC 1122's own wording; session has no home
Questions
- How do I print them double-sided?
- Double-sided, flip on the long edge. Every front sheet is followed by its own already-mirrored back sheet, so print them in the order they come and every answer lands on its own card.
- Can I edit the cards?
- Yes, and that is half the point. Once you own the deck, the "Buy & edit" button here opens all 24 cards in the free flash card maker on this site — reword a definition, delete the ones you do not teach, add your own, and print at anything from two to nine cards a page, rather than the fixed eight of the PDF.
- Can I print a set for every student?
- Yes. Personal and classroom licence: unlimited printing, every class you teach, every year you teach it. It does not cover reselling the file or passing it on to a colleague.
- What if I find a card that is wrong?
- Tell us and we fix it, and we publish what changed. We have withdrawn a whole deck from sale for being out of date rather than quietly patch it.
- Do I need an account?
- No. The file downloads straight away — no account, no email, no card details.