How many examinations for blockchain personnel training
generally speaking, blockchain companies need more technical talents, which is more concive to the development of the company. In addition, the long-term operation of the company is also a very important thing
from a small perspective, blockchain is still unfamiliar to the public, and more often, it needs more publicity and promotion.
2018 has entered the countdown, and the first year of blockchain is coming to an end. In 2018, blockchain technology has received great attention all over the world, and the governments of various countries are actively making efforts in the field of blockchain in an attempt to seize the commanding height of the next instrial innovation. According to the blockchain instry yearbook, in terms of talent supply, there is a large shortage of blockchain talents, and there is a high demand for compound talents. In addition to social training and training, colleges and universities have started blockchain courses
for example, Stanford University, Massachusetts Institute of technology and University of California, Berkeley have begun to offer courses related to blockchain or digital currency. Moreover, many online courses and large-scale open online courses also began to provide relevant training services
it is true that as a "young" technology, the main force of future development of blockchain technology is bound to be young people. But at present, many practitioners in the blockchain instry are self-taught, without systematic professional knowledge training, or only one-sided talents in cryptography, programming, Internet technology, etc
and blockchain technology pays more attention to compound talents with multiple technologies, which may be the internal reason why blockchain talents are increasingly becoming just needed. In 2019, blockchain technical talents seem to have become new professionals, and will be highly competitive
What's the most expensive in the 21st century? It could be blockchain talent
Zhang Yan (pseudonym), who graated from a 211 university in Shanghai with a master's degree, began his internship in a blockchain company this summer, mainly responsible for the collection of instry information. During the internship, his salary is 8000 yuan, and after becoming a regular, his monthly salary will reach 22000 yuan
Zhang Yan's starting salary is much higher than that of fresh graates' first employment. According to the statistics of Shanghai human resources and Social Security Bureau, the average monthly salary of college graates with bachelor's degree is 4793 yuan, and that of graates with master's degree or above is 8001 yuan
according to the analysis of instry insiders, at present, there is a high shortage of talents in the instry, few talents meet the recruitment requirements, and the imbalance between supply and demand leads to a high premium of talents. It is expected that in two to three years, when the blockchain technology is applied and fully blossomed, the relationship between supply and demand in the market will enter a stable stage
how expensive are blockchain talents
"our recruitment has not been smooth. We may have 5-8 people in a quarter, which can only reach 20% of our expectation." Deng Xu, the founder of Yunxiang blockchain, has been hoping to rapidly expand the team to a team of 100 technicians, but he is struggling to find suitable talents
recruitment information of a company
"my ideal blockchain talents mainly have two standards, one is computer foundation, the other is algorithm foundation." Deng Xu said
according to Yan Li, founder of computing power think tank, there are three types of blockchain talents:
first, in terms of content research, most of these talents were originally engaged in financial information, traditional research and other jobs, and after one to two months of training, they can start their jobs
the second is proct technology development, which requires mature computer technology talents, such as research on underlying data development, data storage and so on. They need to redistribute their work areas in the blockchain scenario, and they can adapt to the post demand after two to three months
the third is the refiner of proct requirements, which is the most difficult person to find. They need to understand the business logic of blockchain, dig out pain points, and understand technology, so as to connect the customer's needs with the ability of technical developers
Shang Yang, an analyst of yiou think tank, also pointed out to Zhongxin Jingwei that the essence of blockchain is a distributed encrypted database, and the core idea is decentralization. Blockchain is evolved from bitcoin. Before, there were almost no relevant courses in Colleges and universities, so today's practitioners of blockchain technology are mostly self-taught. Objectively, all those with computer professional background have the conditions to learn. But technology is not the key, the key is to find the appropriate application scenarios. Only in a certain scenario, the data distributed storage can be irreplaceable and bring significant benefits to the enterprise, can it be regarded as a good application scenario, so the application on the chain is still in the exploration stage
"there are too few application-oriented talents," Shang Yang said. The application and transformation of any new technology needs a process. At present, many technicians do not understand procts
According to Deng Xu, there are three main reasons for the shortage of talents in blockchain: on the one hand, the popularity of blockchain is fast, while the number of technicians is small, resulting in the imbalance between supply and demand; On the other hand, blockchain is actually a comprehensive technology, including computer language, algorithm, communication, cryptography and so on. At present, talents trained by colleges and universities generally have only one or two aspects of knowledge reserve. In addition, with the popularity of ICO last year, a large number of new blockchain companies were born, further aggravating the imbalance between supply and demand of blockchainwith the fire of blockchain concept, some colleges and universities began to offer courses, and training institutions also entered the market one after another. Yan Li suggests that top universities with science and engineering majors can continue to give full play to their advantages and cultivate talents for blockchain technology application; In terms of business, it still mainly relies on talents from traditional instries; Social organizations, research centers and other institutions can organize vocational training for talents in the blockchain instry, but good vocational training must last two to three months instead of two or three days of "quick" training
However, Deng Xu pointed out that at this stage, training can only supplement some middle and low-end technical talents for the instry, but it can not solve the problem of high-end talents. Shang Yang also pointed out that universities with relevant courses are also facing the problem of retaining teachers“ On the one hand, it's easy to be poached by enterprises. On the other hand, most people who really understand technology and application choose to open their own companies or speculate in money. ""blockchain technology is the closest technology to money, so many people can't concentrate on technology, and the technology is very complex and boring." Deng Xu said
content source observer network
"chainman College" offers short weekend technical training courses for colleges with a certain programming foundation. You can investigate them and ask about your situation.
the main protocols are as follows: 1. IP internet protocol IP is the heart of TCP / IP and the most important protocol in the network layer. The IP layer receives the data packet from the lower layer (network interface layer, such as Ethernet device driver) and sends the data packet to the higher layer -- TCP or UDP layer; On the contrary, IP layer also transfers packets received from TCP or UDP layer to lower layer. IP packets are unreliable because IP doesn't do anything to confirm that the packets are sent in order or are not corrupted. IP packet contains the address of the host sending it (source address) and the address of the host receiving it (destination address). When high-level TCP and UDP services receive packets, they usually assume that the source address in the packet is valid. It can also be said that IP addresses form the authentication basis of many services, which believe that packets are sent from a valid host. IP confirmation contains an option called IP source routing, which can be used to specify a direct path between the source address and the destination address. For some TCP and UDP services, IP packets using this option seem to be delivered from the last system on the path rather than from its real location. This option exists for testing purposes, indicating that it can be used to spoof the system to make normally forbidden connections. Then, many services that rely on IP source address for confirmation will have problems and will be illegally intruded. 2. TCP if there are already sealed TCP packets in IP packets, then IP will "up" them to the TCP layer. TCP sorts packets and checks for errors, and realizes the connection between virtual circuits. TCP packets include sequence number and acknowledgement, so packets not received in order can be sorted, while damaged packets can be retransmitted. TCP sends its information to higher-level applications, such as telnet's server and client. Applications send information back to the TCP layer in turn, and the TCP layer sends them down to the IP layer, device drivers and physical media, and finally to the receiver. Connection oriented services such as Telnet, FTP, rlogin, X windows, and SMTP require a high degree of reliability, so they use TCP. DNS uses TCP (send and receive domain name databases) in some cases, but uses UDP to send information about a single host. 3. UDP is in the same layer as TCP, but it doesn't care about the order, error or retransmission of packets. Therefore, UDP is not used for connection oriented services that use virtual circuits. UDP is mainly used for query response oriented services, such as NFS. Compared with FTP or Telnet, these services need to exchange less information. Services that use UDP include NTP (Network Time Protocol) and DNS (DNS also uses TCP). Spoofing UDP packets is easier than spoofing TCP packets because UDP does not establish an initial connection (also known as handshake) (because there is no virtual circuit between the two systems), that is, UDP related services are at greater risk. 4. ICMP ICMP is located in the same layer as IP, which is used to transmit IP control information. It is mainly used to provide information about the path to the destination address. ICMP's "redirect" information informs the host of a more accurate path to other systems, while the "unreachable" information indicates that there is a problem with the path. In addition, if the path is not available, ICMP can terminate the TCP connection "gracefully". Ping is the most commonly used ICMP based service. 5. Port structure of TCP and UDP TCP and UDP services usually have a client / server relationship. For example, a telnet service process starts to be idle on the system, waiting for connection. The user uses the telnet client to establish a connection with the service process. The client program writes information to the service process, the service process reads the information and sends a response, and the client program reads the response and reports it to the user. Therefore, the connection is plex and can be used for reading and writing. How do multiple telnet connections between two systems confirm and coordinate with each other? A TCP or UDP connection uniquely uses the following four items in each message: the source IP address, the IP address of the sending packet. Destination IP address the IP address of the received packet. Source port the port of the connection on the source system. Destination port the port of the connection on the destination system. Port is a software structure, which is used by client program or service process to send and receive information. A port corresponds to a 16 bit number. Service process usually uses a fixed port, for example, SMTP uses 25, xwindows uses 6000. These port numbers are "well known" because these addresses and destination addresses are needed to communicate when establishing a connection to a particular host or service
reference model
TCP / IP protocol does not fully conform to OSI's seven layer reference model. The traditional open system interconnection reference model is a seven layer abstract reference model of communication protocol, in which each layer performs a specific task. The purpose of this model is to make all kinds of hardware communicate with each other at the same level. These seven layers are: physical layer, data link layer, network layer, transport layer, session layer, presentation layer and application layer. The TCP / IP communication protocol adopts a four layer hierarchical structure, and each layer calls the network provided by its next layer to fulfill its own requirements. These four layers are: application layer: the layer of communication between applications, such as simple e-mail transfer (SMTP), file transfer protocol (FTP), network remote access protocol (telnet), etc. Transport layer: in this layer, it provides data transmission services between nodes, such as transmission control protocol (TCP), user datagram protocol (UDP), etc. TCP and UDP add transmission data to the packet and transmit it to the next layer. This layer is responsible for transmitting data and determining that the data has been delivered and received. Interconnection network layer: it is responsible for providing basic packet transmission function, so that each packet can reach the destination host (but not check whether it is received correctly), such as Internet Protocol (IP). Network interface layer: manage the actual network media, define how to use the actual network (such as Ethernet, serial line, etc.) to transmit data
the reason why TCP / IP is a protocol family is that TCP / IP protocol includes TCP, IP, UDP, ICMP, rip, telnet FTP, SMTP, ARP, TFTP and many other protocols, which are collectively called TCP / IP protocol. Here we introce the English names and uses of some common protocols in the protocol family: TCP (Transport Control Protocol), IP (Internet Protocol), UDP (User Datagram Protocol), ICMP (Internet control message protocol) and SMTP (Simple Mail Transfer Protocol) Protocol SNMP (Simple Network Management Protocol) FTP (File Transfer Protocol) ARP (address resolution protocol) address resolution protocol from the perspective of protocol layered model, TCP / IP consists of four layers: network interface layer, inter network layer, transport layer and application layer. Among them: network interface layer, which is the lowest layer of TCP / IP software, is responsible for receiving IP datagrams and sending them through the network, or receiving physical frames from the network, extracting IP datagrams and giving them to the IP layer. The inter network layer is responsible for the communication between adjacent computers. Its functions include three aspects. 1、 After receiving the request, the packet is loaded into the IP datagram, the header is filled, the path to the destination machine is selected, and then the datagram is sent to the appropriate network interface. 2、 Processing input datagram: first check its validity, and then carry out pathfinding - if the datagram has arrived at the sink machine, remove the header and hand over the rest to the appropriate transport protocol; If the datagram has not arrived at the sink, the datagram is forwarded. 3、 Deal with path, flow control, congestion and other issues. The transport layer provides communication between applications. Its functions include: 1. Format information flow; 2、 Provide reliable transmission. In order to realize the latter, the transport layer protocol stipulates that the receiver must send back an acknowledgement, and if the packet is lost, it must be retransmitted. The application layer provides users with a set of common applications, such as e-mail, file transfer access, remote login and so on. Telnet uses telnet protocol to provide interfaces registered on other hosts in the network. Telnet session provides character based virtual terminal. File transfer access FTP uses FTP protocol to provide file function between machines in the network. We have learned the related concepts of OSI reference model. Now let's take a look at how TCP / IP protocol implements the network model compared with the seven layer protocol reference model. Layer functions in OSI: TCP / IP protocol family
application layer file transfer, e-mail, file service, virtual terminal, TFTP, HTTP, SNMP, FTP, SMTP, DNS, rip, telnet
presentation layer data format, code conversion, There is no protocol for data encryption
there is no protocol for session layer to release or establish contact with other nodes
the transport layer provides end-to-end interfaces TCP, UDP
the network layer selects routing IP, ICMP, OSPF, BGP, IGMP, ARP, RARP for data packets
the data link layer transmits addressable frames and error detection functions slip, CSLIP, PPP, MTU
the physical layer transmits data iso2110 and IEEE802 on the physical media in the form of binary data. Ieee802.2
data link layer includes hardware interface and protocols ARP and RARP