Solved Network ISO model

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Hello Wes,

Thank you and Don for the A+ video's they helped me alot to get my A+ cert! The next step now is Network+. I folowed the first few video's and i was wondering if you could verify my current grasp of the way a pakets are send across difrent servers for example a SMTP mail server.

Does this mean that my computer goes about make a pakage all they way from layer 7 to layer 1 and that the first mailserver SMTP A translates that all the way back again to layer 7? So it can repack back it to Layer 1 and send it to SMTP server B? Or does it sometimes happen that it is inough to stop at for example Layer 3 to redirect it to the server B?

Hey @Mario-Tork-0 sounds like you have a pretty good grasp of the layers. The sending devices uses the "top-down" approach or Layer 7 - to Layer 1, encapsulating each layers information on the way down . The receiving device uses the "bottom-up" approach or Layer 1 to Layer 7, decapsulating(or processing) each layer's information until the application displays the data. The only thing I would add is that when the sending device, sends the data to a connectivity device like a router, the router starts the "bottom-up" approach until processing reaches the network layer (Layer 3) and determines that the destination IP address is not the routers. The router will not process the network layer as this is the IP address for (in this example) the SMTP server. The router will send the data to the next hop along the journey until the data packet is delivered to the destination IP address.

Hey @Mario-Tork-0 sounds like you have a pretty good grasp of the layers. The sending devices uses the "top-down" approach or Layer 7 - to Layer 1, encapsulating each layers information on the way down . The receiving device uses the "bottom-up" approach or Layer 1 to Layer 7, decapsulating(or processing) each layer's information until the application displays the data. The only thing I would add is that when the sending device, sends the data to a connectivity device like a router, the router starts the "bottom-up" approach until processing reaches the network layer (Layer 3) and determines that the destination IP address is not the routers. The router will not process the network layer as this is the IP address for (in this example) the SMTP server. The router will send the data to the next hop along the journey until the data packet is delivered to the destination IP address.

@wes-bryan

Thank you Wes,

This makes me more confident. Keep up the awsome work you all do!