TeaPort

Intro to Troubleshooting and the Future of Networking Intro to Troubleshooting and the Future of Networking Error-detection: The ability for a protocol or program to determine that something went wrong. Eg: cyclic redundancy check Error-recovery: The ability for a protocol or program to attempt to fix it. Verifying Connectivity Pring: Internet Control Message Protocol Internet Control Message Protocol (ICMP): Mainly used for a router or a remote host to communicate why transmission has failed ba ...

Google crash course Intro to Connecting to the Internet Intro to Connecting to the Internet Various Internet connection technologies. Wans and wireless and Cellular networking. POTS and Dial-up Dial-up, Modems and Point-to-Point Protocols Public switched telephone network (PSTN): This is also refered to as Plain old telephone service (POTS). The system is called USENET and still in use today. In the past, different organizations used the primitive form of Dial-up connection to exchange info. T ...

Google crash course Networking Service Name Resolution DNS(Domain Name System): A global and highly distributed network service that resolves strings of letters into IP addresses for you. Domain Name: The term we use for something that can be resolved by DNS. Eg: Domian Name: www.weather.com IP address: 186.192.1.1 If the company wants to shift their original data center to another place, by using DNS, it can change what IP the domain resolves to and users will not know. DNS is of global struc ...

Google crash course Transport and Application Layers Intro Transport layer: Allows traffic to be directed to specific network applications. Application layer: Allows these applications to communicate in a way they understand. The Transport Layer Multiplex and Demultiplex Processes Multiplexer IP IP Demultiplexer Processes The transport layer handles this multiplexing and demultiplexing through Ports. Port: A 16-bit number used to direct traffic to specific services running on a netwo ...

This is going to be a completely new part of my study in CS. This part won’t last long because I haven’t finished DataStructure and I’m going to learn assembly language. I learn this simply because my server was banned by the GFW and I need some extra knowledge to prevent this from happening again. Good Luck! Google Crash Course The Network Layer Describing the IP addressing scheme and subnetingworks. The Network Layer MAC addresses are useful in a small scale. But they are not ordered. Addres ...

Zhejiang University Understanding of the Puzzle We simply regard the trees as the same as long as they have the same children for every node. Divide and Conquer The representation of a binary tree Build a Binary Tree Judge whether they are Isomers. Representing a Binary Tree Static Linked List: A Special Array. Structure of the Program 12345678BinTree Build();bool Judge();int main(){ Build tree1; Build tree2; Judge isomers; return 0;} Design the Functions 12345678#define ...

Zhejiang University DFS(Depth First Search) 1234567void DFS(Vertex V){ visited[V] = true; for(each adjacent vertex w){ if(!visited[w]) DFS(w); }} Complexity Adjacent List: O(N+E)O(N+E)O(N+E) Adjacent Matrix: O(N2)O(N^2)O(N2) BFS(Breadth First Search) 1234567891011void BFS(Vertex V){ visited[V] = true; Enqueue(V, Q); while(!IsEmpty(Q)){ V = Dequeue(Q); for(each adjacent vertex W of V) if(!visited[V]){ ...

Zhejiang University Graph It is used to represent a many-to-many relationship. It is so powerful because it includes both linear lists(one to one) and trees(one to many). Components Vertex(V): the set of all vertexes. Edge: the set of all sides. (v, w). Double directions. . From v to w (single direction). No multiple edges or multiple loops. A Quick Review: Definition of Abstract Data Type Name: Graph DataSet: G(V, E). V is Nonempty E is limited. Operation Set Graph Create() Graph Insert ...

Zhejiang University Set Operations There are some basic operations about sets. Eg: Union, Intersection, Set Difference… Union-Find Set Problem: There are n nodes. Some of them are connected. How do we know whether arbitrary 2 of them are connected? Answer: Make n sets to include n nodes. Then union those connected. Find whether 2 given nodes are in the same set. Creating Union-Find Set How to Store a Set? Tree. The root will be a set. Each node will be an element. Parental Representation: The ...

Zhejiang University Huffman Tree Question: How can we fit a 100 mark test into a 5 standards judging system? We need to carefully arrange our if clauses in accordance with the frequency of the actual result. (Decision Tree) Cost: ∑ratio×layers\sum\rm ratio\times layers∑ratio×layers Definition Weighed Path Length: A binary tree with n nodes with weight w. The distance between root and each leaf is l. Then the WPL for each leaf node will be WPL=∑i=1nwklkWPL = \sum_{i=1}^nw_kl_k WPL=i=1∑n​wk​lk​ ...