The simple answer is that a networking system is simpler, cheaper, and more reliable if it is implemented in terms of layers. Each layer accepts responsibility for a small part of the functionality. Having a clean separation of function between layers means that multiple layers do not need to duplicate functionality. It also means that layers are less likely to interfere with one another.
A simple example: in the TCP/IP protocol suite, the IP layer is very simple. All it does is (a) provide a uniform format for messages to be passed between computers that will work from anywhere on the internet (regardless of what kind of link layer is being used), and (b) provide a uniform addressing model for computers on the Internet. IP does not ensure that messages are delivered correctly or reliably, it doesn't ensure that messages are not duplicated, and so forth. That's the job of higher layers. TCP, which is layered on top of IP, allows two computers to exchange messages of arbitrary length. Essentially, TCP takes care of fragmenting the messages into IP packets (which have a maximum size) and making sure that the entire contents of those messages arrive at their destination and are reassembled, in order, without duplicated or missing fragments. The TLS protocol (formerly known as SSL) is layered on top of TCP and provides encryption, digital signatures, and assures the integrity of the message against deliberate or accidental modification. Application protocols layered on top of TCP and/or SSL provide higher-level functions, such as delivery of email or a web page.
Similarly, protocol layers underneath IP are used to deliver messages on specific kinds of data links. Wireless LAN is somewhat different from a DSL circuit, cable TV Internet, point-to-point fiber optic link, or a wired Ethernet.
It prevents changes in one layer from affecting other layers
OSI
* physical layer is the lowest layer of the OSI model and deals with "mechanical,electrical,fuctional and procedural means required for transmittion of the data according to the OSI defination,
application -top of osi model physical- bottom of osi model
Offcourse osi..... TCP/IP is an implementation of osi....
OSI stands for Open system interconnection model. Application layer is the seventh layer in OSI model.
Repeaters operate at the physical layer of the OSI model.
hub work at physical layer of osi model
p2p y osi
The OSI Model stands for Open Systems Interconnection. The answer to the question which layer of the OSI model are layers capable of functioning is at all layers.
Explain OSI reference model with revant diag
In the OSI reference model, that would be layer 3 (network).In the OSI reference model, that would be layer 3 (network).In the OSI reference model, that would be layer 3 (network).In the OSI reference model, that would be layer 3 (network).