, required operation not performed
553 The mailbox name is not available and the requested operation is not performed
354 start the message input to "." End
554 operation failed
Several basic features of UDP protocol
(1) UDP is a connectionless protocol to transmit data before the source and terminal do not establish a connection, when it wants to transfer simply to crawl data from the application, and as q
Let's look at what happens when we enter http://www.mycompany.com:8080/mydir/index.htmlin the browser, behind the scenes.First HTTP is an application layer of protocol, in this layer of protocol, is just a communication specification, that is, because the two sides to communicate, we have to agree to a specification beforehand.1. Connection when we enter such a request, first to establish a socket connectio
Software download for analysis: Wireshark-win32-1.10.2.exeRead the guided Tour1. Analyze and apply the ARP protocol2. Analyzing IP Protocols3. Analyzing the ICMP protocol1. Analysis of the format and content of ARP messages(1) The ARP request message of ping 172.18.3.132:000108000604000100e04c512ae8ac12038e000000000000ac120384Physical network Type hardware type:0001-ethernet (1)Protocol type
Network transmission protocol and http protocol, transmission http protocolOverview: it refers to the constraints and specifications for communication between the server and the client. The data interaction between the client and the server is not disorganized and must follow (based on) certain specifications.
A) HTTP and HTTPS Hypertext Transfe
tolerated, so we adopt the UDP transport protocol. But the UDP protocol itself is non-connected and does not provide quality assurance. The high-level protocol rtp/rtcp based on UDP can provide traffic control and congestion control services together. The graph gives a RTP/UDP/IP-based H. 264 frame for video transmission.H. 264 RTP encapsulation strategy for vid
HTTP network protocol (IV) and http network protocolSecure Web HTTPS
HTTP has three obvious disadvantages:
Communication uses plain text (not encrypted), and the content may be eavesdropped.
If you do not verify the identity of the contact, you may experience disguise.
Unable to prove the integrity of the message, so it may have been tampered. Although there
the computer.7. Network wake-up: for administrators, you can use the wol (wake up on LAN) function to remotely start the network, execute maintenance tasks, and then remotely shut down the network. You can also perform maintenance automatically, which greatly facilitates the administrator.Implementation conditions: similar to the "Incoming call start" section, t
核心提示：-->With the development of the IP network to the multi-service network, especially the development of VoIP in recent years, it is inevitable to transmit signaling messages in the IP network. But in the IP network cannot provide high-quality transmission services like mtp3 and ATM, so the ITU-T proposed an im
). The data is often in line with higher-level protocols for upper-Layer Networks. It is compatible with data, and data type information is also available in frames. The connection layer protocol does not care about what is contained in the data. Frame is likeEnvelopeTo package the data.
Ethernet and WiFi are currently the most common connection layer protocols. Through the connection layer protocol, we c
Part1. The most familiar strangersCompared with the TCP/UDP protocol, the HTTP protocol may be more familiar, as everyone can see the http://xxx.com word everywhere. But, reallyThe students who are aware of the HTTP protocol may be just a few, and many people don't even know what "404" means. And this article, it is to let everyone more in-depth understandingNext
(NetWork Basic Input/Output System). This protocol is developed by IBM and is mainly used for the small LAN of dozens of computers. The NetBIOS protocol is an Application Programming Interface API that can be used by a program on the LAN. It provides a unified command set for the program to request low
to start, control, and end a session, including control and management of multiple two-way messages, so that the app can be notified when only part of a continuous message is completed, so that the data that the presentation layer sees is contiguous, and in some cases, data represents the presentation layer if all the data is received by the presentation layer. Example: Rpc,sql and so on.
The functionality of this layer includes whether to choose the error recovery
Tags: col transmission broadcast tip Local computer network Tran technology familySingle shared broadcast channel, if two or more than two nodes simultaneously transmit, will interfere with each other (interference) conflict (collision): Nodes receive two or more signals at the same time → Receive failed! The MAC protocol uses a distributed algorithm to determine how nodes share channels, that is, when deci
The Transport layer provides communication services to the application layer above it, which belongs to the highest level of the communication section and is also the bottom of the user's function.
Two hosts are actually communicating with each other in a two host application process . Communication between application processes is also known as end-to-end communication .
The messages of different processes in the application layer are delivered down to the transport layer through different
Digression: Originally wanted to follow the internet level from the bottom up review these agreements, but today really have to break the case, DHCP has to say!Host from one network to another network, then the structure of IP address will change, today's mainstream has the following several modification scenarios:(a) Change of address:The host changes its address when moving to a new
no total Length field, the IP layer will not know how many bytes in 46 bytes are the contents of the IP datagram.TTL is the maximum number of routers a datagram can pass, he specifies the lifetime of the datagram, theinitial value of the TTL is usually set by the host , once the number of a route it will be subtracted 1, when the field equals 0 o'clock, the datagram will be discarded, and send an ICMP message to notify the source host, This is also a simple algorithm for IP
html resulting to the browser;
release tcp connection;
browser html Text and display the content;
HTTPNon-stateful nature of the ProtocolThe HTTP protocol is stateless (stateless). That is, when the same client accesses a page on the same server for the second time, the server cannot know that the client has visited and the server cannot distinguish between different clients. The stateless nature of http simplifies the design of
The RSVP Resource Reservation Protocol may seem vague to many people. Therefore, this is a type of communication rule on the Internet. Its working mode mainly protects link sharing. Now let's take a detailed look at its basic situation.
Resource Reservation Protocol, RSVP) is a set of communication rules that allow one source to play multiple receivers for videos and other high-bandwidth information) the ch
The content source of this page is from Internet, which doesn't represent Alibaba Cloud's opinion;
products and services mentioned on that page don't have any relationship with Alibaba Cloud. If the
content of the page makes you feel confusing, please write us an email, we will handle the problem
within 5 days after receiving your email.
If you find any instances of plagiarism from the community, please send an email to:
and provide relevant evidence. A staff member will contact you within 5 working days.