Embedded Network sensor: sensitive unit, intelligent Processing Unit and TCP/IP communication protocol interface
Sensor operating mechanism: the sensor will be measured by the physical volume into electrical signals, through the ad conversion to digital signal, after the microprocessor data processing, the results are transmitted to the network; the data exchange with the network is done by the TCP/IP protocol-based network interface.
Artificial intelligence material features: ability to perceive changes in environmental conditions
(traditional sensor), identification, Judgment function (processor), instructions and self-acting function (guide)
Layered model of TCP/IP protocol
Layer: Vertical stack structure, each layer is responsible for dealing with a part of the problem.
In the Protocol software of the transmitting machine, the packets go down and down through the network, then upstream in the protocol software of the receiver.
OSI Seven layer model:
Application layer: The interface between the user's application and the network.
Presentation layer: Negotiates and establishes the interchange format for data, which is responsible for the task character set or number conversion required between devices. It is also responsible for compressing data to reduce data transfer and also to encrypt.
Session Layer: Describes how the protocol software should be organized to provide the required functionality to the application. The OSI committee believes that access to remote terminals is an essential issue, so they define the fifth layer to deal with it.
Transport Layer: Provides end-to-end reliable transmission between the destination host and the source host.
Network layer: The definition of the interaction between the host and the network. Defines the basic data units transmitted over the network, as well as the definition of the destination addressing and routing.
Data Link layer: Because the underlying hardware can only transmit bit streams, the layer protocol must be defined as the format of the frame, and the recognition method of frame boundary is given. Error detection mechanism
Sub-layer:
Media access Control sub-layer: Responsible for physical addressing and physical access to network media. Only one device can transfer data on any type of media at a time. Multiple units will disrupt the signal.
Logical Link Control sub-layer: Establishes and maintains a data link connection between devices. Responsible for flow control and error correction in this layer. -An unconfirmed connection-free service, a connection-oriented network service.
Physical layer: The standard for defining physical connections
TCP/IP layer four network model
Application layer: The user calling application at the top level accesses the available services over the TCP/IP Internet. Applications that interact with each transport layer protocol are responsible for receiving and sending data.
Transport Layer: Provides communication services between applications. This service is also called end-to-end communication. Transport layer to systematically manage the flow of information, but also to provide reliable transmission services to ensure that the data error-free, non-disorderly order. To divide the transmitted data stream into small chunks. Send each packet together with the destination address to the next layer.
Network layer: Handles communication problems between machines. It accepts the transport layer's request and transmits a packet with the destination address information. The layer encapsulates packets into an IP datagram, fills in the header of the datagram, uses the routing algorithm to determine whether to deliver the datagram directly, or passes it to the router, and then transmits the datagram to the appropriate network interface. The layer also processes the incoming datagram, verifies its validity, and uses the routing algorithm to determine whether the packet should be handled locally or forwarded. If the destination of the packet is in the same network as the local computer, the layer software removes the packet header and then selects the appropriate transport layer protocol to handle the packet. Finally, the network layer also sends and receives ICMP error and control packets as needed.
Link layer: The lowest level, which is responsible for IP packets and sends the datagram out through the selected network. The link layer includes a device driver, or it may include a complex subsystem that uses its own data link protocol.
TCP/IP Protocol family overview
Link layer: The Data Link layer or network interface layer, which typically includes the device drivers in the operating system and the corresponding network interface cards in the computer network. They work together with the physical interface details of the cable (or any other transmission medium).
Network layer: Enables the host to send IP datagrams to any network, and can be transmitted independently to the destination. The order of arrival and the order of delivery may be different.
IP protocol: The IP packet is transferred from the source host to the destination host through the network interconnection system. IP packets, also known as IP datagrams, provide unreliable, non-connected packet delivery services. Unreliable refers to the fact that it does not guarantee that IP datagrams will reach their destination successfully. IP only provides the best transport service. The reliability of any requirement must be provided by the upper layer. No connection means that IP does not maintain any status information about subsequent datagrams. Each packet is processed independently of each other. All TCP, UDP, ICMP, and IGMP data are delivered in a datagram format.
ICMP (Internet Control Message Protocol) Internet-controlled Message Protocol
IGMP (Internet Group Message Protocol) Internetwork Management Protocol
ARP (Address Resolution Protocol) addresses Resolution Protocol: Hardware address to IP address mapping, from IP address to physical address of the transformation is through the table to achieve. The ARP table is placed in the memory processor. If the IP module does not find the hardware address of the IP address of a destination address in the ARP table, it uses the broadcast Ethernet address to send an ARP request to each computer on the Internet, and when the other computers in the network find the address and its own IP address, it relaxes a response packet to the source Ethernet address. If the target computer does not exist, the ARP response is not available, and the local module discards the IP packet for the destination address of the housing network.
RARP (Reverse Address Resolution Protocol) Reverse URL Resolution Protocol
Transport Layer: Provides end-to-end communication for applications on two hosts.
TCP: A connection-oriented protocol that allows a single machine to send a stream of messages to other machines on the network without error. It divides the incoming message stream into the message segment and passes it to the Internet layer. At the receiving end, the TCP receive process assembles the received message into the message stream output. TCP also handles traffic control in order to avoid sending too many messages to the receiver in a fast-forwarding direction so that the receivers cannot process them. The TCP segment contains the port number of the source and destination ports
First 6 sign bit
urg-Emergency pointer Valid
ack-confirm the serial number is valid
psh-receiver should give this segment to the application layer as soon as possible
Rst-Reconnect
syn-Synchronous serial number to initiate a connection
fin-originator completes the Send task
TCP provides connection-oriented, end-to-end, reliable communication services to applications.
UDP (User Datagram Protocol): unreliable, non-connected protocol for applications that do not require the ordering and traffic control capabilities of TCP. It is mainly used to submit packet packets with more important speed than accuracy. such as transmission of voice and video messages.
Application tier: Provides a common set of applications to users. TELNET,FTP, SMTP, DNS, NNTP.
Ethernet Technology:
CSMA: Carrier monitoring multi-access with collision detection is a method of media access control.
Unicast
Broadcasting
Multicast (multicast)
