Communication
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[![](https://camo.githubusercontent.com/1d761d5688d28ce1fb12a0f1c8191bca96eece4c/687474703a2f2f692e696d6775722e636f6d2f354b656f6351732e6a7067) ](https://camo.githubusercontent.com/1d761d5688d28ce1fb12a0f1c8191bca96eece4c/687474703a2f2f692e696d6775722e636f6d2f354b656f6351732e6a7067)    
_[Source: OSI 7 layer model](http://www.escotal.com/osilayer.html) _