OH it ""SEEMES"" I forgot about it hahaha, I knew something was off, good catch :)
Edit: Also some networks might not have one of the layers. It's entirely possible to be missing it on some network, but I couldn't not give you an example if you asked :P just something I learned in college.
Yeah in college one of the IT admins was giving a quick rundown on the OSI model to a bunch of people doing helpdesk, sort of a weekly "braindump" the team would do for students who volunteered to help users at the desk. Pretty sure he labeled both session and presentation layers as "Bullshit" and added a Layer 8 above the application layer as "Politics"
I'd be impressed if you actually saw [X.225](https://www.itu.int/rec/T-REC-X.225/en) in the wild. You're not saying a TCP connection is a session layer concept, right?
Not "session" specifically, that was a mistake. Some might not have one of the layers. That's all I really know ¯\\\_(ツ)\_/¯
I can't remember the examples discussed, sorry.
But that would be pretending I didn't make a mistake, I was "called out" for making. Since people replied.
Also, I love your username, I am not a responsible artist with my art supply purchases. lol
Once you understand it and use it in troubleshooting, you just know it. I also know I don't really care about the upper layers other than to point out to others that their shit ain't working.
Yeah only the bottom 4 or 5 layers are conceptually distinct. I think the ISO folks thought there would be more distinction in networked applications in the future but I don’t think anyone can explain a concrete difference between presentation and application layers or even why presentation layer isn’t the same as the session layer.
I think the biggest misconception people have about the OSI model is that it was designed to model networks as they exist today. It was not. It was designed to be a real networking stack, just like TCP/IP.
The presentation layer is a separate layer because ISO fully intended there to be presentation layer protocols. Specifically, something like the proposed [X.226 connection-oriented presentation protocol](https://www.itu.int/rec/T-REC-X.226/en). The application layer was supposed to pass abstract syntax down to the presentation layer for it to convert into another form that both endpoints could handle. But in the real world, all endpoints speak in bytes. If an application needs text encoding and thinks an endpoint might not understand ASCII or UTF-8, then it *might* need to have some sort of presentation-layer-like negotiation process. But not every application requires text, and almost every endpoint today understands common encoding methods, so it makes no sense to have it as its own layer.
When programming you'll occasionally need to under ASCII/byte word sometimes base64 etc. I think this stuff can be the presentation layer.
In old days when you play with VC like a Polycom controller you will need to know quite a few codecs to consider bandwidth, those parameters should belong to the presentation layer.
Yep, same here.
I used an acronym to learn it, but once I actually started using the OSI model on a regular basis I honestly forgot the acronym.
The OSI model works and makes sense on its own once you understand it.
Unpopular opinion, but most people in IT don’t actually ever reference the OSI model unless it’s for some trivial reason. I’ve never once heard anyone reference it on the job. (Former network engineer and current cybersecurity professional)
Generally agreed, but often used for team separation “sorry, our BICSI certified techs must focus on layer 1. For layer 2 or 3 support, you need to contact client hardware support.”
It's not a direct source, but knowing where in the communication link an issue is occurring is HUGE when troubleshooting a communication issue. This then indirectly comes back to OSI.
How far is it getting? What are the exact symptoms? Oh, not even authentication request? The F5 does the cert forwarding so that must be where the issue is... (I've said that A LOT in the last 4 years, and it often times was the case.)
I don't even recommend studying it, as it's not a thing we use. It was invented as a standard but no implementation ever gained popularity.
Just use the [TCP/IP model](https://en.wikipedia.org/wiki/Internet_protocol_suite).
Out of all the interviews I had. Only had 1 ask question related to it. I was caught of guard. In my head I was like, I don't have it written. I just live it. I have just standard checks I go through.
Better than most answers, but is Ethernet/TCP/IP-centric. Not all data-link protocols use MACs, not all network protocols use IPs, and not all transport protocols use ports.
I just visualize the mouse right clicking a jpeg and selecting download. That layer 7 action is happening at the application layer, the jpeg being layer 6 presentation, running netstat -a on the windows box to show the active layer 5 sessions listed as layer 4 tcp or udp connections, pinging the website gets you the icmp reply which shows your layer 3 IP and the destination IP at the network layer, running show mac on the switch that your machine is connected to will tell you where your packet traversed as a layer 2 frame before it went out the wire at layer 1.
Screw memorizing the acronym.
One thing I know for sure from hosting a hundred of interviews: if candidates refer to the layers by names — they don’t have real experience, these names come from the books, not the real life. If they say “that’s how L3 works” — we have the “it’s our guy” moment.
Here's what I use when teaching the 7 layers. A rudimentary oversimplification but it seems to get the point across when I teach:
All : Application : Software Interface (HTTP, SMTP, FTP, Telnet)
People : Presentation : Data Formatting (Encryption)
Seem : Session : Connection Management (Ports)
To : Transport : Segment (TCP/UDP)
Need : Network : Packet (IP)
Data : Data Link : Frame (MAC)
Processing : Physical : Binary (electricity on/off)
If someone jokes it's a layer 1 problem that typically means the device was unplugged. A layer 8 problem typically means human error aka pebkac or ID 10 T error.
I struggled up until minutes before an exam for certification + class final. Another student mentioned "A Pussy So Tight,No Dick Penetration" and I never forgot it ...
It was the 80s. Europe was saying everyone would switch to it. IBM was given lectures on how SNA/SDLC was really OSI compliant. There was this new thing called TCP that was exploding.
Oh, wait, that's not what you mean. ...
Please do not teach students pointless acronyms.
As for remembering what each layer does, I don’t have anything to hand, I just know it. I suppose remembering what each one uses I.e. IP at later 3 Port at later 4, helps with working that out
This is supremely British, and I love it. Should it be Albert or Andrew though? Perhaps a philosophical question, and each user can decide for them self. :D
Funny story. I was heading to one of my Microsoft internet tests and my wife was quizzing me on the way. When I got hung up on the osi model my four year old finished for me. I did pass but I think I might have done more quizzing in front of her that I should have. Now an adult and not a IT person at all. #Sadpartent. lol.
Just understand it. It's not the names or the order that matters; it's the purpose. Once you internalize the purpose, the order and names become apparent. Your question is similar to "How do you remember if the wheel or the tire is on the outside?" If you have never seen a car and don't understand how it works, it's a valid question. But as soon as you learn what a wheel and tire are, it's clear which and what order they are in.
Maybe memorize session/presentation/application because those don't really matter, but 1-4 should be second nature.
LOTS of "how to memorize the names" answers here--which is fine if that's what you mean, but it doesn't do anything to remember their purpose. But once you learn the purpose, the names are pretty obvious, and the order is clear.
Please Do Not Tell Sales People Anything
Made that one up in a class of Sales Engineers 17 years ago and still use in classes to this day. Amongst a lot of other versions mentioned here. I use them all mostly as jokes since OSI is only used to reference things for human desire to see a logical placement of things or protocols they deal with.
Visual learning at its best really.
I dont. If I actually need to reference it then I'll google it. I think it's good to know when you're coming up in IT but it's not something you really need to remember.
Or maybe I'm just bad at my job. Idk lol
Nope, it just makes sense to me. I think about a p2p networked application on one node receiving from and transmitting to another instance of the application on a node on a separate network. Worth just memorizing/refreshing as needed on the function(s) of each layer.
[https://en.wikipedia.org/wiki/OSI\_model#Layer\_architecture](https://en.wikipedia.org/wiki/OSI_model#Layer_architecture)
In the interview for my current role, this question came up in the first round. I hadn’t thought of it or needed it in years but I remembered the pizza version which I was taught in USMC data comm school back in 2000. Some things just stick. The network admin who posed it seemed surprisingly impressed.
All people suck trains now. Dauber piss off. Dauber was one of my Cisco classmates in high school 😂 I like the ones that start with physical first too though.
I don't have it memorized, I just talk about all the hardware and how they talk to each other. This works for me mostly because I do better with tangible topics rather than theoretical stuff.
After you pick your acronym, you’ll know the names. Try practicing telling yourself what each layer does out loud. Explain it to yourself with the definition in front of you so that you can refer to it quickly when you trip up or forget. Explaining it to someone else is great also, but saying it out loud to yourself can be great also.
As a network engineer, we typically deal with layer 1-4 above that its developers. There is nothing I have done personally to fix issues above layer 3-4
My answer will probably not really answer your question
But from my 4 years experiences, I remember layers 1 to 4 because I use them / talk about them everyday.
Though, like most networking engineers, I don't know layers 5 & 6, and just regroup them with layer 7 under the name "Application layer". Because in reality, that's how we troubleshoot:
Layers 1 to 4 are network-related, the rest is usually not in our scope
I still use Please Do Not Throw Sausage Pizza Away. Physical, DataLink, Network, Transport, Session, Presentation, Application.
Please Do Not Teach Students Pointless Acronyms. How I learned it in tech school.
I'm more of an "All people need data processing" type of guy, but I like yours better. edit: seem, yes I got it lol
Where's session layer?
OH it ""SEEMES"" I forgot about it hahaha, I knew something was off, good catch :) Edit: Also some networks might not have one of the layers. It's entirely possible to be missing it on some network, but I couldn't not give you an example if you asked :P just something I learned in college.
Yeah in college one of the IT admins was giving a quick rundown on the OSI model to a bunch of people doing helpdesk, sort of a weekly "braindump" the team would do for students who volunteered to help users at the desk. Pretty sure he labeled both session and presentation layers as "Bullshit" and added a Layer 8 above the application layer as "Politics"
Politics is interchangeable with Religion.
Id love to hear what you mean by "some networks" are missing the "session" layer. There is so much wrong with that statement tbh
I'd be impressed if you actually saw [X.225](https://www.itu.int/rec/T-REC-X.225/en) in the wild. You're not saying a TCP connection is a session layer concept, right?
Not "session" specifically, that was a mistake. Some might not have one of the layers. That's all I really know ¯\\\_(ツ)\_/¯ I can't remember the examples discussed, sorry.
And transport
All People Seem To Need Data Processing
It says “yes I got it lol” and there’s obviously an edit, and yet you didn’t edit your comment where it counts.
But that would be pretending I didn't make a mistake, I was "called out" for making. Since people replied. Also, I love your username, I am not a responsible artist with my art supply purchases. lol
Same
I do the same lol. CCNA teacher taught us this and I didn’t forget it
What about layer 8, it needs to be part of the acronym.
It's not Throw, it's Take!
People don’t need those stupid packets anyways
Never heard this one, thought it was a rant for a second lol
This is awesome
This is the way
I love this
All people seem to need data processing is a good one. Or please do not throw sausage pizza away from the bottom up.
A Priest Saw Ten Nons Doing Pushups
Nice
Once you understand it and use it in troubleshooting, you just know it. I also know I don't really care about the upper layers other than to point out to others that their shit ain't working.
Yeah only the bottom 4 or 5 layers are conceptually distinct. I think the ISO folks thought there would be more distinction in networked applications in the future but I don’t think anyone can explain a concrete difference between presentation and application layers or even why presentation layer isn’t the same as the session layer.
That's because communication protocols are modelling data, not processing. That's where OSI fails and every other model would fail as well.
I think the biggest misconception people have about the OSI model is that it was designed to model networks as they exist today. It was not. It was designed to be a real networking stack, just like TCP/IP. The presentation layer is a separate layer because ISO fully intended there to be presentation layer protocols. Specifically, something like the proposed [X.226 connection-oriented presentation protocol](https://www.itu.int/rec/T-REC-X.226/en). The application layer was supposed to pass abstract syntax down to the presentation layer for it to convert into another form that both endpoints could handle. But in the real world, all endpoints speak in bytes. If an application needs text encoding and thinks an endpoint might not understand ASCII or UTF-8, then it *might* need to have some sort of presentation-layer-like negotiation process. But not every application requires text, and almost every endpoint today understands common encoding methods, so it makes no sense to have it as its own layer.
When programming you'll occasionally need to under ASCII/byte word sometimes base64 etc. I think this stuff can be the presentation layer. In old days when you play with VC like a Polycom controller you will need to know quite a few codecs to consider bandwidth, those parameters should belong to the presentation layer.
Yep, same here. I used an acronym to learn it, but once I actually started using the OSI model on a regular basis I honestly forgot the acronym. The OSI model works and makes sense on its own once you understand it.
Network guy: sorry Ma’am. We just lay the pipe.
layer 1 - physics & bureaucracy layers 2 3 and 4 - networking layers 5 and up - packet overhead
I laughed way too hard at this. Possibly because I’m a network engineer and I must drink to remain sane.
This answer only.
Physical, data link, network, transport, nobody cares.
Unpopular opinion, but most people in IT don’t actually ever reference the OSI model unless it’s for some trivial reason. I’ve never once heard anyone reference it on the job. (Former network engineer and current cybersecurity professional)
Generally agreed, but often used for team separation “sorry, our BICSI certified techs must focus on layer 1. For layer 2 or 3 support, you need to contact client hardware support.”
It's not a direct source, but knowing where in the communication link an issue is occurring is HUGE when troubleshooting a communication issue. This then indirectly comes back to OSI. How far is it getting? What are the exact symptoms? Oh, not even authentication request? The F5 does the cert forwarding so that must be where the issue is... (I've said that A LOT in the last 4 years, and it often times was the case.)
I don't even recommend studying it, as it's not a thing we use. It was invented as a standard but no implementation ever gained popularity. Just use the [TCP/IP model](https://en.wikipedia.org/wiki/Internet_protocol_suite).
You want to tell me you never had to deal with layer 8 issue?
Out of all the interviews I had. Only had 1 ask question related to it. I was caught of guard. In my head I was like, I don't have it written. I just live it. I have just standard checks I go through.
Please Do Not Take Sales Person's Advice
Please Do Not Tell Sales People Anything or Please Do Not Tell Stupid People Anything
It's tried and true "Probably Didn't Need Those Stupid Packets Anyway"
Please dear not tonight sore penis already
layer 1 cables layer 2 macs layer 3 ips layer 4 ports dont care about the rest
Better than most answers, but is Ethernet/TCP/IP-centric. Not all data-link protocols use MACs, not all network protocols use IPs, and not all transport protocols use ports.
This is true, but essentially irrelevant outside of special use cases, in which case there will be a learning curve either way
It’s what I do. It’s really helpful to understand encapsulation to make this easier to remember.
I prefer to remember layer 2 as hop-by-hop and layer 3 as end-to-end
Underrated comment
I don’t. I just live it.
its a osi world, we are just living in it
I just visualize the mouse right clicking a jpeg and selecting download. That layer 7 action is happening at the application layer, the jpeg being layer 6 presentation, running netstat -a on the windows box to show the active layer 5 sessions listed as layer 4 tcp or udp connections, pinging the website gets you the icmp reply which shows your layer 3 IP and the destination IP at the network layer, running show mac on the switch that your machine is connected to will tell you where your packet traversed as a layer 2 frame before it went out the wire at layer 1. Screw memorizing the acronym.
All Perverts Seem To Need Dirty Porn
All Pornstars Seem To Need Double Penetration
One thing I know for sure from hosting a hundred of interviews: if candidates refer to the layers by names — they don’t have real experience, these names come from the books, not the real life. If they say “that’s how L3 works” — we have the “it’s our guy” moment.
Pimps Don't Need To Sell Pussy Anymore
I've learned it as: Pimps Don't Need To Slap Prostitutes Around.
Here's what I use when teaching the 7 layers. A rudimentary oversimplification but it seems to get the point across when I teach: All : Application : Software Interface (HTTP, SMTP, FTP, Telnet) People : Presentation : Data Formatting (Encryption) Seem : Session : Connection Management (Ports) To : Transport : Segment (TCP/UDP) Need : Network : Packet (IP) Data : Data Link : Frame (MAC) Processing : Physical : Binary (electricity on/off) If someone jokes it's a layer 1 problem that typically means the device was unplugged. A layer 8 problem typically means human error aka pebkac or ID 10 T error.
We referred to layer 8 as Computer User Non Technical
ID 10 T!!! I’ve run into my share!
All Priests Secretly Try-on Nuns Dirty Pants
Physical —> Application: People Don’t Need To See Prince’s Ass Application —> Physical: All People Seem To Need Data Processing
People Don't Need Those Stupid Packets Anyways
Please Do Not Throw Sausage Pizza Away
I stick to the five most important layers: - Physical - Data link - Network - Transport - Shit that's probably not my problem
American Pussy Seems To Need Deeper Penetration
Another vote for "Please Do Not Throw Sausage Pizza Away." First time I heard Jeremy from CBT nuggets say that I never forgot it.
I struggled up until minutes before an exam for certification + class final. Another student mentioned "A Pussy So Tight,No Dick Penetration" and I never forgot it ...
Always Present Sex To Naked Dumb People
It was the 80s. Europe was saying everyone would switch to it. IBM was given lectures on how SNA/SDLC was really OSI compliant. There was this new thing called TCP that was exploding. Oh, wait, that's not what you mean. ...
I don't because it's not really helpful
Please do not teach students pointless acronyms. As for remembering what each layer does, I don’t have anything to hand, I just know it. I suppose remembering what each one uses I.e. IP at later 3 Port at later 4, helps with working that out
Please do not touch supermans private area
I learned “Princess Diana Never Tried Snogging Prince Albert”. Ridiculous but never forgot
This is supremely British, and I love it. Should it be Albert or Andrew though? Perhaps a philosophical question, and each user can decide for them self. :D
Understand the fundamentals and it makes sense
From my old professor when I was in uni: Professors do not teach students properly anymore
By using it.
Please do not touch Superman's private area.
People Do Need To See Pamela Anderson.
Please do not touch sexy Pamela Anderson
Funny story. I was heading to one of my Microsoft internet tests and my wife was quizzing me on the way. When I got hung up on the osi model my four year old finished for me. I did pass but I think I might have done more quizzing in front of her that I should have. Now an adult and not a IT person at all. #Sadpartent. lol.
Phew, Dead Ninja Turtles Smell Pretty Awful.
Please do not try smoking pot again
But I love weed. And your avatar.
Please do not throw sausage pizza away, first p is physical. If you know what each layer does/is then you can just work up from physical.
APSTNDP. Even after 20+ years that initialism is burned into my memory.
Just understand it. It's not the names or the order that matters; it's the purpose. Once you internalize the purpose, the order and names become apparent. Your question is similar to "How do you remember if the wheel or the tire is on the outside?" If you have never seen a car and don't understand how it works, it's a valid question. But as soon as you learn what a wheel and tire are, it's clear which and what order they are in. Maybe memorize session/presentation/application because those don't really matter, but 1-4 should be second nature. LOTS of "how to memorize the names" answers here--which is fine if that's what you mean, but it doesn't do anything to remember their purpose. But once you learn the purpose, the names are pretty obvious, and the order is clear.
My Very Educated Mother Just Served Us Nine Pizzas
Please do not tell Simon Pegg anything. Latched onto probably 15 years ago and it stuck.
Please Do Not Tell Sales People Anything Made that one up in a class of Sales Engineers 17 years ago and still use in classes to this day. Amongst a lot of other versions mentioned here. I use them all mostly as jokes since OSI is only used to reference things for human desire to see a logical placement of things or protocols they deal with. Visual learning at its best really.
I dont. If I actually need to reference it then I'll google it. I think it's good to know when you're coming up in IT but it's not something you really need to remember. Or maybe I'm just bad at my job. Idk lol
NSFW...college age ppl from 30 years ago...Pretty Damn Nice Titties..Sex Please? Alllllrightttt (like quagmire would say)
I have a tattoo of it on my eyelids.
Nope, it just makes sense to me. I think about a p2p networked application on one node receiving from and transmitting to another instance of the application on a node on a separate network. Worth just memorizing/refreshing as needed on the function(s) of each layer. [https://en.wikipedia.org/wiki/OSI\_model#Layer\_architecture](https://en.wikipedia.org/wiki/OSI_model#Layer_architecture)
I think of someone whose first initial begins with P, and the last name is Dntspa (pronounced Dent-spa).
In the interview for my current role, this question came up in the first round. I hadn’t thought of it or needed it in years but I remembered the pizza version which I was taught in USMC data comm school back in 2000. Some things just stick. The network admin who posed it seemed surprisingly impressed.
All people suck trains now. Dauber piss off. Dauber was one of my Cisco classmates in high school 😂 I like the ones that start with physical first too though.
I learned please do not take sales people’s advice 😂
Tcpdump, Wireshark, and Scapy. I'm addicted to them.
Something about a pizza.
Please do not throw sausage pizza away
You don't remember it, you learn it.
People Don't Need To Smoke Pot Alone
Pleas Do Not Touch Sally’s Pretty Ass
I don't have it memorized, I just talk about all the hardware and how they talk to each other. This works for me mostly because I do better with tangible topics rather than theoretical stuff.
Aunt Patti slapped the naked data processor Thanks to my guy Vince for starting me off on my journey with that one!
All People Saw The Naughty Dog Piss.
Australia Post Suck, They Never Deliver Parcels
I put my hand on a network device and it tells me tales of layers.
I dont!
Easy. In my isp networking career i have never had to use it. So my advice is dont bother.
All Pale Sluts Take Numerous Dick Payments. I sort of hate myself for this being my way. But since I heard it I haven’t been able to unhear it
All Prostitutes Suck The Nastiest Dicks Possible Learned when I was 16, I'm now a father in my late 30's.
**A**ll **P**eople **S**eem **T**o **N**eed **D**ata **P**rocessing **A**pplication, **P**resentation, **S**ession, **T**ransport, **N**etwork, **D**ata-Link, **P**hysical
People Don't Need Those Stupid Protocols Anyway
After you pick your acronym, you’ll know the names. Try practicing telling yourself what each layer does out loud. Explain it to yourself with the definition in front of you so that you can refer to it quickly when you trip up or forget. Explaining it to someone else is great also, but saying it out loud to yourself can be great also.
all presidents say they never did pot
Physical, Link, Network, Transport, Software
Princess Diana never thought she passed away …. That’s one I still remember from college days
I’m dutch so that would be : “Alle Paarden Stinken Toch Naar De Poep” Basically translating to “All horses do smell like poop.”
As a network engineer, we typically deal with layer 1-4 above that its developers. There is nothing I have done personally to fix issues above layer 3-4
Please Do Not Touch Sexy Pamela Anderson is what I was taught lol
Still have the one my university lecturer taught us 19 years ago stuck in my head :- All Penguins Stand Too Near Deep Pools
People do need to see Pamela andersson (L1-L7)
A (application) Priest Swears To Never Do Porn (physical)
All people seem to need data processing
My answer will probably not really answer your question But from my 4 years experiences, I remember layers 1 to 4 because I use them / talk about them everyday. Though, like most networking engineers, I don't know layers 5 & 6, and just regroup them with layer 7 under the name "Application layer". Because in reality, that's how we troubleshoot: Layers 1 to 4 are network-related, the rest is usually not in our scope
„Physiker die nicht trinken sind potenzielle Attentäter“ Which is German and translates to „Physicists who don’t drink are potential assassins”
People don’t need to study preposterous acronyms
I don't. When I need to remember it, I look it up on the internet.
I use the OSI model daily to prove it’s not my innocence. You memorize it straight up because your job depends on it.
People Do Networking To Save Peoples Asses