Twelve, ADSL MODEM
ADSL is currently the mainstream form of broadband Internet access. Let us introduce some common faults and maintenance methods when using ADSL, hoping to help you.
Common faults 1: When dialing, the program always gives "Connect Communication Service" without reacting, and the error code prompt is not seen.
This situation is often caused by the connection parameters of the ADSL MODEM itself. When we access the ADSL service, it is not possible to get the username and password. You have to get the name of the ADSL installation protocol (more common like a 1483 Bridge LLC), configure the protocol name (more popular like g.lite), VCI, VPI Numerical value. Therefore, we can open the ADSL MODEM itself setting options to see if these setup parameters are consistent with the parameters provided by China Telecom. If it is inconsistent, the dial is not successful.
Common faults 2: ADSL often disconnects
If you find ADSL frequently in the installation process, the synchronization is very slow, this is a troublesome thing. It may involve many aspects, including ISP access server failures, line faults, line interference, ADSL MODEM faults (fever, poor quality, compatibility), network card (slow speed, driver old) failure, etc. Before the experts who found the Telecom Bureau were solved, I suggested that you can first check the following: Is the ADSL telephone line connector is stable; ADSL is far from power cord and high-power electronic equipment; no telephone extension between ADSL portal and separators , Fax machine and other devices; properly mount the separator; ensure that ADSL Modem is well dissipated. If you don't have any problems in determining the above operation or if you can't solve the problem, you only call or go to the Telecommunications Bureau to ask.
Common failover three: The lamp on the ADSL panel is constantly flashing, the network cannot be connected
In fact, you only have to understand the meaning of the lamp representative on the ADSL panel, and the problem is very easy to solve. The signal light on the ADSL MODEM panel is used to display the network connection situation, and the specific meaning is as follows:
"ADSL" light: used to display the synchronization of Modem, often bright green light indicates that the MODEM and the local end can be synchronized normally; the red light indicates that there is no synchronization; the flash green light indicates that the synchronization is being established.
"10baset" light, is used to display whether MODEM and NIC or HUB is connected properly. If this light is not lit, the MODEM is definitely not passing between the computer. When there is data transfer in the network cable, this light will flash slightly.
"ATM25" light shows the status of ATM25, which is generally not available.
"MAINT" light, related to remote management, generally constant.
"Power" light, power display.
Common faults four: Sometimes ADSL access speed is not much faster than ordinary dialing modem
The situation in which ADSL accesses is slow, as follows:
1. If you visit the foreign site, the access will be affected by factors such as export bandwidth and other partial sites.
2. Since ADSL technology has high quality requirements, and the current ADSL currently uses ADSL (ie, rate adaptive ADSL), if the telephone line between the telephone to the user is subject to external factor interference Radsl adjusts the user's access speed based on the low and deepening of the line quality and the remote approach of the transmission distance.
Common fault five: ADSL interrupt time
ADSL is a technique based on twisted pair transmission. The twisted pair is to be entangled with each other in a certain law, which can effectively resist the external electromagnetic field interference. However, most telephone lines in the market are parallel lines, which are used from telephone company junction boxes to the user's phone. This is a parallel line. This is very disadvantageous to ADSL transmission. The too long non-twisted pair transmission will cause connection to unstable, DSL The light flashes, etc., which affects the Internet. Since ADSL is superimposed on a high-frequency digital signal on the baseband voice voice of the ordinary telephone line, the addition of any device from the telephone company to the ADSL filter will hazard to the normal transmission of the data, so don't do not before the filter Telephone, telephone anti-theft player and other equipment. Common fault six: According to the speed of ADSL, local download should be more than 1m, but many times there are only 100 ~ 300K
This is a problem with a rate unit. Name 56K MODEM download is 5-6K. The 56K unit is bit, while the rate at which the download is displayed by Byte. 1BYTE = 8bit. So when downloading is 200KB, it has already reached 1.6Mbit, which is already quite fast. Due to many reasons such as server and client hard disk read and write speed, local download speeds cannot play the greatest capacity of ADSL2-8Mbit / s. We also expect to appear faster servers.
Common faults seven: ADSL's indicator is often removed
In the ADSL indicator, the most important lamp is "ADSL" instruction. When there is no problem in the ADSL line, this light should be green. However, some users will turn off the line when the "ADSL" indicator is normal, and it is better to restart MODEM. This happens to do not do a proxy server, no network users of the firewall or router, is this? Because there is a "10BASE-T" port on the ADSL Modem, this port is a terminal network, and it is actually a HUB port. Although it is a 10m port, the ADSL's uplink bandwidth is only a few hundred kbit / s. If the user's LAN is directly connected to Hub, Hub then connects to the client, many of the ADSL-independent packets will occupy the ADSL uplink channel, and ADSL cannot control the broadcast storm in the LAN, such as exceeding ADSL uplink transmission. Ability, packet will be loaded into the ADSL cache, if the amount of data continues to increase, cache overflow, causing ADSL "sleep" phenomenon. This is only restarted MODEM. The solution is that the non-strong user can make a dual-NIC agent server (must be dual network card), which can partition direct communication between the MODEM and the local area network to avoid the above problems. Unit users prefer to use firewalls or routers.
Common fault eight: sometimes failure when virtual dialing
ADSL virtual dial-up software has the following error messages:
1. Dial-up window Display "Begin Negotiation" and then wait, and finally pop up the menu "Time Out". This situation indicates that the network is not available. The reason is: the network cable on the 10baset port on the ADSL is not connected; the ADSL network is unlocked, you can restart ADSL and try again.
2. Dial-up window Display "Begin Negtiation", then "Authenticating", last "Authentication Faled". This situation indicates that your account or password is incorrect.
3. Dial-up window Display "Begin Negotiation", then "Authenticating", then "Receiving Network Parameter", finally pop up the menu "Time Out". This situation indicates that the dial IP address is already full, please call later.
Common fault nine: "ADSL" lights red, then contact interrupt
The "ADSL" light on ADSL is the most important indicator of ADSL, which is the first step in which ADSL can communicate.
"ADSL" lights have several states:
1. "ADSL" light If you are green, it indicates that the user-end MODEM and Telecommunications Bureau's MODEM has established a physical connection - this is called "synchronization", which is the first step in ADSL's normal work, is the most important step. 2. "ADSL" light If it turns red, it indicates that the user's MODEM and the MODEM of the telecommunications have been disconnected - this is called "fail".
3. "ADSL" lights If it is flashing, it indicates that the user's MODEM and Telecommunication Bureau's MODEM is trying to establish a connection, that is to say synchronous.
When the user adds ADSL MODEM plus a power supply for more than a few ten seconds, the "ADSL" light changes from "red-green flash-long green", which is the process of establishing a synchronization. If the ADSL Modem is using the "ADSL" indicator phenomenon, it means that there is strong interference on your phone line at this moment; one of the connections on the telephone line is not connected, there is a loose phenomenon or the line fault.
Solutions and precautions:
1. The ADSL line cannot be separated and extension, and the phone can only be taken from the separator Phone port, otherwise the ADSL is incorrect.
2. The connections on the line must be connected, especially the connector inside the user's house.
3. If the telephone line is too long from the telecommunications branch box, the parallel line should be replaced with twisted pair and improve the anti-interference ability of the line.
4. ADSL is sometimes interference from the weather cause, such as heavy rain. Users can wait a few hours will naturally recover.
