port protocol

The TCP/IP state machine, as shown in:In the TCP/IP protocol, the TCP protocol provides a reliable connection service with a three-time handshake to establish a connection, as shown in 1. (SYN packet indicates flag bit SYN=1,ACK packet indicates flag bit Ack=1,syn+ack package represents flag bit syn=1,ack=1)(1) First handshake: When a connection is established, client A sends a SYN packet (SEQ_NUMBER=J) to

Msnp9 Protocol Analysis Report 1. Connection The MSN Messenger protocol is built on TCP/IP. In addition to direct "point-to-point" communication between file transmission and voice chat, all other scenarios are performed through the server. Logically, there are three types of servers with their respective roles: Dispatch server (DS)-the server on which the client first connects. Allocates appropriate notif

segmented, and then the segmented NAL unit is packaged in step 1 ways. The partitioning scheme is as follows:Where nsize is the NAL element size before splitting, n is the size of the NAL unit after splitting. The number of cells after the K split. The size of the last cell after the split may be less than N, when the RTP payload must be filled with the same size as the previous tile, at which point the padding identity bit value in the RTP header is 1.3, the SEI, the parameter set and other sm

Mobile device Management (MDM) and OMA (OTA) DM Protocol Wizard (ii)--WAP Protocol (1)On the "Mobile Device Management (MDM) and OMA (OTA) DM Protocol Wizard (i)"16. Can I access WiMAX devices directly from the Web server?See "WAP Protocol (1)--6th WAP Network Deployment" in this article17. Can I use TCP instead of WDP

First, the introduction The Protocol deals with properties and methods that act like abstract classes in Java, and the types in swift implement agreed properties and methods by complying with the protocol. The protocols in Swift are declared using the Protocol keyword. The protocol in Swift also has a very interesting

I. background and functions of the SIP protocolSIP (Session Initiation Protocol) is developed to help provide advanced telephone services that span the internet. Internet telephone IP telephone) is evolving to a formal business telephone model, and SIP is an important member of the series of protocols to ensure the implementation of this evolution.SIP is part of the IETF standard process. It is built based on simple SMTP Mail Transfer

Small Knowledge Points: Socket: An interface between the application layer and the transport layer, one endpoint of the communication. Divided into streaming sockets (providing bidirectional ordered without duplication, no boundary record of the data stream) and datagram Sockets (bidirectional, not guaranteed to be reliable and orderly and without duplication). Port: integer identifier, 16 bit, 0~65535,1024 below is reserved bit, such as 80 is HTTP

External Network access intranet database-p2p penetrationIntranet database after deployment, such as local (dynamic) public IP, you can use nat123 dynamic Domain name resolution, real-time domain name resolution to the local public network IP, fixed domain name, thus through the domain name access, connected to the corresponding database application. such as the intranet without public IP, to achieve external network access to the intranet database, using the NAT123 scheme is: Change the

identify a computer that is unique across the world Ip+mac+port can identify a unique network communication-based application software worldwide. URL address: Identify a resource that is unique across the worldDNS default Port 535 TCP Protocol (reliable Protocol) Three-time handshake to establish a connectio

1. Windows platformExecute under Windows command-line window:1. View all port usagec:\>Netstat-anoProtocol local address external address state PIDTCP 127.0.0.1:1434 0.0.0.0:0 LISTENING 3236TCP 127.0.0.1:5679 0.0.0.0:0 LISTENING 4168TCP 127.0.0.1:7438 0.0.0.0:0 LISTENING 4168TCP 127.0.0.1:8015 0.0.0.0:0 LISTENING 1456TCP 192.168.3.230:139 0.0.0.0:0 LISTENING 4TCP 192.168.3.230:1957 220.181.31.225:443 established 3068TCP 192.168.3.230:2020 183.62.96.18

1456TCP 192.168.3.230:2927 117.79.91.18:80 established 4732TCP 192.168.3.230:2929 117.79.91.18:80 established 4732TCP 192.168.3.230:2930 117.79.91.18:80 established 4732TCP 192.168.3.230:2931 117.79.91.18:80 established 47322. View the usage of the specified portc:\>netstat-aon|findstr "9050"Protocol local address external address state PIDTCP 127.0.0.1:9050 0.0.0.0:0 LISTENING 2016P: See, Port is occupied

ICMP Internet Control Message Protocolis generally considered an integral part of the IP layer and is generally used by the IP layer or higher (TCP, UDP).The ICMP message is transmitted inside the IP datagram.The format of the ICMP message is as follows:The first 4 bytes of the message are the same: 8bit type, 8bit code, 16bit test and.The ICMP packets have different message types, and the different types are determined by the 8bit type and the 8bit code together. There may be more than one code

First, the Knowledge Reserve:1. Three elements of network communication:IP Address: inetaddressIdentification of devices in the networkHard to remember, host name availableLocal loopback address: 127.0.0.1 host name: localhostPort numberThe logical address used to identify the process, and the identity of the different processesValid ports: 0~65535, where the 0~1024 system uses or retains ports.Note: Not the so-called physical port!Transport protocolR

restriction rule, there may be a situation where the error results in another error, and the error will result in an endless loop). When sending an ICMP error message, the message always contains the IP header and the first 8 bytes of the IP datagram that generated the ICMP error message. In this way, the module that receives the ICMP error message will associate it with a particular protocol (as judged by the