Smart connection to improve ADSL network speed

manyi

Smart connection to improve ADSL network speed [Copy link]

　1. Discover the problem

　　Our school has an electronic reading room with 24 computers. We applied for ADSL to access the Internet. ADSL is said to be broadband, but since using ADSL, the Internet speed has always been slow. When multiple people are online, I used about 6k/s to download a software, which is slower than ISDN. My original connection method is shown in the figure.

　　

　　 The two switches are connected in series using RJ-45 cross-twisted pair cables. Any interface on the switch is connected to any Ethernet port of the ADSL router using a parallel twisted pair cable. The WAN port of the router is connected to the Ethernet interface in the ADSL-Modem using a cross-twisted pair cable dedicated to the ADSL-Modem. Since the Internet speed is not high, I tested it and found that the speed is very fast when a single machine is online, and the speed of switch "1" is faster than that of switch "2" when multiple machines are online.

　　2. Solve the problem

　　In view of the above situation, I experimented with multiple connection methods and finally determined the best connection method. The specific method is shown in the figure.

　　

　　 Use two parallel twisted-pair cables to connect the cascade ports in the two switches to any Ethernet port in the ADSL router. The WAN port of the router and the Ethernet interface in the ADSL-Modem are still connected with the cross-twisted-pair cable dedicated to the ADSL-Modem. After the connection, the speed of Internet access is improved. When multiple people are online, the speed of downloading a software is about 17k/s, which is quite satisfactory.

　　3. Remaining problems

　　There is a problem with the connection in the above figure: if only the switch is turned on but not the router, the computers connected to the two switches cannot transmit data to each other. However, once this ADSL-dedicated router is turned on, it starts to dial the Internet connection through the ADSL-Modem (unless the dial-up function is turned off in its settings). Fortunately, there are not many times when data is transmitted between them, and most of the time it is still used to access the Internet.

　　Before editing this article, I contacted the author, Mr. Ma. They used to use common routers, ISDN, and D-Link switches to achieve shared Internet access for more than ten machines. Since the speed of ISDN is relatively slow, they did not feel the speed difference caused by the first connection method. However, after using ADSL dedicated routers, ADSL-Modem, and D-Link switches, they found the speed difference caused by the connection method. For this reason, I consulted several engineers who have been doing network installation and debugging for a long time, but they could not explain the real reason. Here, I sincerely hope that you will participate in the discussion and jointly build and maintain our campus network.