OSI (Application layer)

[smvitayush1]

Could anyone explain the following:

Application layer functions typically include identifying communication partners, determining resource availability, and synchronizing communication. When identifying communication partners, the application layer determines the identity and availability of communication partners for an application with data to transmit. When determining resource availability, the application layer must decide whether sufficient network resources for the requested communication exist. In synchronizing communication, all communication between applications requires cooperation that is managed by the application layer.

Could anyone please explain using an example.

[Nadav · Accepted solution]

I feel as though that description of L7 is partly inaccurate.

I checked youtube for a video which may give you proper examples to better understand OSI, but truth is there is quite a bit of inaccurate stuff going around. Here are some resources which should elucidate matters:

The OSI stack in general:  https://support.microsoft.com/en-us/help/103884/the-osi-model-s-seven-layers-defined-and-functions-explained

An example of the OSI in action for a particular application: http://www.inetdaemon.com/tutorials/basic_concepts/network_models/osi_model/real_world_example.shtml

OSI model isn't an exact science, it's just one model to teach you how to abstract parts of IT infrastructure whose configuration is for the most part independant from one another. It also teachs you how to think in subsystems which integrate with one another. 

If you're studying for a certification, just go with what's written in the official study guide ;)