Differences and connections between DDN, ASDL, and ISDN

Narrowband access refers to enterprise Access Services with a speed of less than 2 Mbps

BytesISDN

-The Integrated Service Digital Network (ISDN) is a Digital Network based on a public telephone Network. It can transmit high-speed Digital signals in two directions using common telephone lines for extensive communication Services, including voice, data, and images. Because it integrates the functions of various individual business networks, it is vividly called "one-line communication ". -Basic ISDN services: ISDN is mainly used for Internet access, new voice services, company network interconnection or remote access, leased line connection backup for large commercial users, backup for traffic overflow, desktop video system, and video conferencing. -ISDN value-added services: the maximum difference between the ISDN quasi-leased line mode and the general ISDN mode is that you can obtain an Internet static IP address and a free subdomain name, it is used to build your own Web site, establish your own Intranet and E-Mail systems, and information application systems. Compared with DDN Services, it has advantages such as low cost, simple installation, unlimited time, and traffic. 263 data port has advanced technology and a wide range of ISDN trunk line resources can be expanded to 2600 lines). It provides high-speed network channels to provide quality services to users based on their different needs.

BytesDDN

-DDN (Digital Data Network) is a Digital transmission Network that uses Digital channels such as optical fibers, Digital microwave channels, and satellites to provide permanent or semi-permanent circuits and transmit Data signals. Advantages of the ddnleased line DDN business is different from the traditional analog leased line. It features a digital leased line, high transmission quality, low latency, high communication rate, and can be selected between 2.4Kbps-2 Mbps as needed; the route can be automatically rolled back, with high reliability and availability. It uses point-to-point or one-to-point dedicated data lines, especially for users with large business volume and strong real-time performance, in addition, it can centrally monitor network devices in a graphical manner. The front-line can be used for multiple purposes. It can call, fax, transmit data, and form a conference and television system, or set up your own Virtual Private Network VPN), set up a network management center and set up your own Web site, you can also obtain static Internet IP addresses and free subdomains to build your own Intranet and e-mail systems and information application systems. The computer automatically completes circuit connection, test, alarm, and route detour, making network management intelligent and reducing unnecessary human errors. -DDN-based access refers to the transmission of digital data between a user and an Internet access service provider over a physical leased line, and the transfer rate reaches 64 Kbps to 2 Mbps. For different customer needs, especially those who have strict bandwidth requirements, we have introduced the dedicated line exclusive mode. That is, the DDN Access Service ensures the bandwidth from the client to the data port and the Internet egress. -The DDN method has a high transmission rate, good stability, and low investment in the early stage. It is permanently connected to the international Internet and can smoothly transition to frame relay.

BytesADSL

-Adslasypolicric Digital Subscriber Line), which is an asymmetric Digital user loop. It uses Digital encoding technology to obtain the maximum data transmission capacity from an existing copper telephone Line, at the same time, it does not interfere with conventional voice services on the same line. The reason is that it transmits data at frequencies other than telephone voice transmission. That is to say, users can make phone calls or send faxes while surfing the Internet. This will not affect the quality of calls or speed down the download of Internet content. -ADSL can provide end users with 8 Mbps downstream transmission rate and 1 Mbps upstream transmission rate, which is nearly 200 times faster than the traditional 28.8K analog modem. This is incomparable to ISDN (integrated business data network) with a transmission rate of kbps. In addition to the speed, ADSL can also bring us other convenience. First, ADSL uses a leased line connection. That is to say, the ADSL modem and the network are always connected, thus eliminating the need for dial-up Internet access, of course, it will not be annoying. On the other hand, ADSL can make calls and surfing the internet at the same time without interfering with each other. This is very similar to ISDN. What's different is that the telephone communication of ISDN is implemented on the SDN channel, which causes the problem of making phone calls when the local power is down, there is no such situation in ADSL. No matter whether your home has electricity or not, you don't have to worry about making a phone call. -Two functions are designed for ADSL: high-speed data communication and interactive video. The data communication function can be used for Internet access, company Remote Computing, or dedicated network applications. Interactive videos include on-demand videos (VoD), movies, and games for high-speed network video communication.

BytesOther access methods

-263 The data port can also provide users with special access services such as game private networks, Digital Microwave Access, and satellite access based on their specific needs.