The Open System Interconnection Reference Model (OSI Reference Model or OSI Model) is a description for communications and computer design. It was made as part of the Open Systems Interconnection (OSI) initiative. OSI 7-layer Model was created by the International Standards Organization (ISO). It is set of communication standards developed to correct the chaos of multiple protocols
My first introduction to the OSI Model was via a force fed training session with Jay McMaster in Kapuskasing, Ontario. We were up there for a customer site meeting. He flew, I drove. This was my first indication that Jay may have been smarter than me. The second one was the ease to which he recited the naming assignments within the OSI model and … my favorite at 11:00 pm at night (at 40 below Celsius), his ability to do Octel Range IP block assignments in his head. Years later I would know Jay to be a super excellent CTO, all around nice guy. Anyways…, his advice to memorization of the layers? Mnemonic phrases!!
The one that stuck with me = (P)lease, (D)o, (N)OT, (T)ake, (S)ales, (P)eoples, (A)dvice or Please Do Not Throw Salami Pizza Away or Please Do Not Tell Secret Passwords Anytime – You get the idea.
Layer 1, Physical: The Physical layer’s name says it all. This layer defines the electrical and physical specifications for the networking media that carry the data bits across a network.
For Frontier, this would be any physical technology that supports the transport of the data link frames or cells listed in the preceding row. Examples include Category 5 unshielded twisted-pair (UTP), T1 etc.
Layer 2, Data Link: As its name suggests, this layer is concerned with the linkages and mechanisms used to move data about the network, including the topology, such as Ethernet or Token Ring, and deals with the ways in which data is reliably transmitted.
For Frontier, Data link = Any data link technology that supports the transport of IP packets. Examples include Frame Relay, ATM, Ethernet, Point-to-Point Protocol (PPP) or Multilink PPP (MLP). Our Bonded ADSL would fall into this layer.
Layer 3, Network: This is the layer on which routing takes place, The Network layer defines the processes used to route data across the network and the structure and use of logical addressing.
For Frontier Network = anything at the IP Layer
Layer 4, Transport: The functions defined in this layer provide for the reliable transmission of data segments, as well as the disassembly and assembly of the data before and after transmission.
For Frontier, Transport = RTP and UDP (media); TCP and UDP (signal)
Layer 5, Session: The Session layer establishes, maintains, and manages the communication session between computers.
For Frontier, Session = H.323, SIP, MGCP, and Megaco
Layer 6, Presentation: This layer is concerned with data representation and code formatting.
For Frontier, Presentation = CODECs
Layer 7, Application: The Application layer provides services to the software through which the user requests network services. Your computer application software is not on the Application layer. This layer isn’t about applications and doesn’t contain any applications. In other words, programs such as Microsoft Word are not at this layer, but browsers, FTP clients, and mail clients are.
For Frontier, Application – IP Call Control, CallManagers, and human speech
I thought I would add a few new ones !
I suspect the International Organization for Standardization people will reject it, but Wikipedia may keep it for a bit ! We will see.
Layer -0 – Ditch,Trench or Conduit – also known as the backhoe layer (I would like to be formally noted as the originator of this, no payment required, just a constant reference to my acknowledgement the backhoe and all related evilness is relevant to the OSI model) that includes the ditch witch, fusion spicer, bad splices, bad actual splicing technicians
Layer 0 – Colo – yes, in celebrating the Frontier Data Centre, we are proud to officially submit Layer 0 to the IEE board for consideration
Layer 8 – Political (old favorite.. not officially sanctioned by the ISO) (I should note the originator of this was actually John Jeza, also a member of the Jay fan club).
Layer 9 – Financial (yup, the good old budget cut, creative finance)
Layer 10 – Act of Vendor Stupidity (bad design, overzealous sales rep, bad IoS (sorry for the specific reference), vendor mergers “we are sorry, the product that you are using is no longer in service, please try your purchase again”
We could keep going …. Thanks Jay!
About Frontier Networks
Frontier Networks Inc. is headquartered in Toronto, Ontario and provides Broadband Internet or MPLS, Voice lines or Cloud PBX (a replacement to old phone systems), cloud servers , colocation and our new Physical Security offering to Canadian Retail and Multi Site customers who demand world-wide coverage from a ‘new’ network. “We like to do traditional things in a non-traditional way”. Frontier has built a network that connects to other networks. Think of them like a large ‘backbone’ of interconnected networks. They connect to every phone company, cable company, wireless and hydro/utelco in Canada and the US through a series of well-connected Points of Presence (POPs). Simply put ‘we don’t suck’.
See more at: http://www.frontiernetworks.ca/blog