Recalling the calculation network part1-Chapter One, Preface

Keywords-Internet, Internet, Network

Original ppt:

Why can we go online? -----ISP

We go online by paying fees to ISPs (China Mobile, China Telecom), obtaining the right to use the required ip address, and accessing the network through the ISP.

Keywords-Internet edge part and core part, host, end system

The edge part is also called the resource subnet, and the
core part is also called the communication subnet.

End system communication essence

End-system communication mode-keywords-C/S P2P (peer)

The essence of P2P is still the C/S communication method. In
simple terms, the P2P communication method is for the end system, that is, the host can be both a Client and a Servier.

The core network composition that provides communication

router

Circuit switching, packet switching

Circuit switching using switches

The function of the router ------- "" "Store and Forward
Storage"-"This is the process of putting it into the cache and temporarily storing it

Three kinds of exchanges----》circuit exchange, message exchange, packet exchange

did you see? There is also an interval for each packet in packet switching.
This part of the time is to deal with the delay and queuing delay ----- "the process of queuing and eating in the cafeteria

A simple understanding of the access network is a bridge to graft the communication subnet and the resource subnet.

The following is about network classification, that is, the classification of communication subnets, which is the core part of the Internet.



Transparent here means invisible, the protocol is invisible to the service, and the service does not need to know the underlying protocol.