How to disassemble adsl modem d link 2500u. Network based on xDsl modems

DSL stands for Digital Subscriber Line (digital subscriber line). DSL is one of the technologies that allows connecting local networks, telephone exchanges over ordinary copper pairs, providing access to remote corporate networks provide access to the Internet. The existing telephone lines are used to organize the DSL line; This technology is good because it does not require additional telephone cables. Modern technologies DSLs make it possible to organize high-speed Internet access for both the average user and enterprises and organizations, turning ordinary telephone cables into high-speed digital channels. And the speed data transmission depends only on the quality and length of the line connecting the user and the provider (from 32 Kb/s to 50 Mb/s). Based on the foregoing, we can draw an initial conclusion about DSL technology: DSL technology allows you to organize high-speed channels on existing copper lines, which entails a reduction in the financial costs of an enterprise or organization for connecting to the Internet and connecting remote LANs.

SDSL (Single Line Digital Subscriber Line - single-line digital subscriber line)

SDSL is a technology that provides symmetrical data transmission at speeds from 64 Kb/s to 2 Mb/s. In SDSL technology, only one pair of wires is used to organize a digital channel, the maximum transmission distance is limited to 8 km (copper core diameter 0.5).

ADSL (AsymmetricDigitalsubscriberline- asymmetric digital subscriber line)

ADSL is a technology that provides asymmetric data transfer, that is, the data transfer rate from the network to the user is much higher than the data transfer rate from the user to the network. ADSL is an ideal technology for organizing Internet access. When organizing such connections, users usually receive much more information than they transmit.

HDSL (highBit- rateDigitalsubscriberline- high-speed digital subscriber line)

HDSL is a symmetrical data transfer technology, that is, the transfer rates in both directions are equal. Due to the transmission speed (1.544 Mb/s over two pairs of wires and 2.048 Mb/s over three pairs of wires), telecommunications companies use HDSL technology to organize T1/E1 circuits.

So, having briefly become acquainted with DSL technology, we can draw some conclusions. DSL technology provides high speed data transfer. Different variants of DSL technologies provide different data transfer rates, but the speed of this equipment is still much higher than the speed of a conventional modem. DSL technology - the most cost effective profitable option to join the LAN, telephone exchanges, organizing access to the Internet and access to corporate networks of an enterprise or organization.

VDSL- the most advanced xDSL solution, a product of the evolution and convergence of ADSL and G.SHDSL technologies.

Compared to ADSL, VDSL has a significantly higher data transfer rate: from 13 to 56 Mbps in the direction from the network to the user (Downstream) and up to 11 Mbps from the user to the network (Upstream) when operating in asymmetric mode; the maximum throughput of a VDSL line when operating in symmetrical mode is approximately 26 Mbps in each direction of transmission. Depending on the required bandwidth and type of cable, the length of the VDSL line ranges from 300 meters to 1.3 km.

Connection diagram.

The cable from the phone to the splitter is not included in the table, since this cable usually comes with the phone.

Description of the network diagram

To build a network, it is necessary to install a multiport industrial DSLAM switch in the CDP. Comes from the switch telephone cable RJ-11 to the splitter, it is also possible to connect a telephone to the splitter. The splitter is connected via RJ-11 to a telephone cable and a signal goes to the enterprises through this cable. At the enterprise, everything is connected in the reverse order: a modem is connected to the splitter via RJ-11, to the modem via RJ-45 USPD, to which, in turn, electricity meters are connected via RS-232. Telephone cables are not included in the calculation, as the networks of the telephone operator are used.

Hardware Specifications

DAS-3248/DC/C

With Gigabit Ethernet (GE) uplink network interfaces, the DAS-3224/3248 IP DSLAMs provide a cost-effective solution for direct connection to IP networks via an Internet router or LAN switch. IP DSLAMs allow providers to arrange for subscribers broadband access to the network over copper using existing telephone lines. The devices support ADSL/ADSL2/ADSL2+ technology and advanced IP services including QoS, multicast and subscriber management. These features help eliminate bandwidth congestion and provide noise-free and efficient transmission of video, voice and data on the network. Triple Play technology enables the simultaneous transmission of bandwidth-intensive content: voice, video and data - through a single infrastructure. DAS-3224/3248 series devices support uplink aggregation (aggregation of GE uplinks into one logical interface). In addition, thanks to the Daisy Chaining option, all connected devices can use one GE uplink channel. Equipped with 48 ADSL2+ ports.

DSL-2540U/BRU/C The DSL-2540U/BRU/C modem is designed for small office and home networks. It allows you to quickly and easily get broadband Internet access and share an ADSL link between multiple users. With a built-in ADSL interface supporting up to 24Mbps downstream, firewall, QoS, and a built-in 4-port switch, this device provides small offices and home users with a convenient and cost-effective way to build a secure, high-speed, network bottleneck-free network. » places a communication channel to the outside world.

DSL-30CF/RS

The splitter is required when using the same telephone line for voice and data (ADSL) transmission.

Supports ADSL, ADSL2, ADSL2+, Annex A, L, M

1 RJ-11 phone line connector

1 RJ-11 connector for connecting a telephone (or PBX)

1 RJ-11 connector for ADSL connections- modem

At home, I use home Internet via ADSL technology D-link modem. I will say that access to the Internet is not reliable. I don't know who else to blame: either the ISP; or a modem with a communication line; Or maybe the user is to blame :). Only I always noticed that the modem gets very hot during operation. Thoughts to disassemble it and somehow improve the cooling of strongly heated elements arose a long time ago, but somehow all hands did not reach. And then one day, on a spring day, I took it apart.
Turned it on, disassembled, watched about twenty minutes of online video, began to grope for hot elements. I immediately found the culprit of global warming, this is a large BGA (chip).

After her palpation, I burned my index finger quite badly. That is, in fact, the entire modem, together with the case, heats up only from it. On the reverse side, at the location of the microcircuit, found darkening printed circuit board. Although I know that the operating temperature of some radioelements is quite high, and a temperature of 70-105 ° is normal, I was sorry for the poor thing and all her surroundings, so I decided to put a radiator on it. I found a suitable radiator on an old motherboard from a computer, which was glued to the microcircuit.
Using a screwdriver, I took the radiator from the rightful owner. I decided to place it on the modem chip using hot glue. I ran around the shops, found hot glue only in a TV workshop, gave 150 rubles for it.
Hot glue in our small town is a very rare thing, so I immediately developed a fallback: we glue the radiator on superglue, applying it (in small dots) to the four corners of the microcircuit, we smear the center with KPT-8 thermal paste, sold in every computer store for 30 rubles.
Here, it is important to calculate everything correctly so that the paste spread over the microcircuit does not mix with superglue. Since the radiator did not fit completely into its intended place, it had to be cut off.
In my case, the screen of another, large microcircuit (not heated) interfered with the placement of the whole radiator, but on the exact same modem of a friend, this screen was missing, so I glued the radiator completely to it. To glue the radiator, apply a thin layer of glue to the chip, after degreasing the surface.
We press the heat sink to the microcircuit, and we drive it a little from side to side, so that the glue layer becomes more even and thinner. After thinking, I decided to glue the rest of the radiator. We glue it to the screen, and to the fins of the main radiator, aligning them. Maybe the heat transfer will be small, but it will not get worse for sure.
I was convinced of this by heating a small part of it and the screen. According to the instructions, the drying time of the glue is 24 hours, but if you do not move the radiator, then the product can be used earlier, because the glue is quite thick and even without drying it holds well. We assemble the modem and know: now we are definitely not in danger of overheating. Well, of course, we note the increased speed and stability of the Internet connection at times :).

D-LINK DSL-2500U belongs to network devices entry level. Judge for yourself: there is no wireless communication module, there is only one network port, the processor is modest, the amount of memory is small. The scope of this modem can be described by the phrase "one modem - one computer." There are still many places on the periphery where a connection from Rostelecom is the only way to get broadband Internet access. DSL-2500U was specially developed for the countries of the former CIS, so it will work perfectly even on old telephone lines, the quality of which leaves much to be desired in the provinces. From our article you will learn how to connect it, configure it and make it work effectively.

Package contents and price of the D-Link 2500U modem

The device is shipped in cardboard box with a signature orange and black design. Inside are:

The patch cord included in the kit is simplified (UTP4). It has only four signal lines instead of the classic eight, so old network cards may not work with such a cable. Keep this in mind if you own an early 00's computer or an old laptop.

D-Link 2500U has been produced for a good ten years, so it can still be found on sale, although the expediency of buying such equipment is doubtful, because it costs about a thousand rubles, and for this amount you can already buy ADSL wifi router. The price of a modem in the secondary market varies widely. A “bare” device without cables and a splitter can be found for 100 rubles. A complete set with a box and a network adapter will cost 500–800 rubles.

Appearance, purpose of indicators and technical characteristics

The modem case is made of matte black plastic with ventilation holes on top. On the front panel there are LEDs for indicating operating modes, and on the back - interface connectors and a socket for connecting network adapter.

The presence of only one LAN port indicates that this device is clearly not intended for the office.

Table: the purpose of the indicators on the front panel of the modem

Modem Specifications

Several varieties (revisions) of the DSL-2500U were released, which differ only in the type of processor and flash memory. Their characteristics are almost the same.

Table: comparison of models of different versions

Video: review of the D-link DSL-2500U router

Connecting the modem to client equipment

To install and configure an Internet connection using ADSL technology, you need to follow a few steps:

1. Connecting a modem router to a telephone line and a computer.
2. Configuring the computer's network interface for successful work with modem.
3. Configuring Internet connection settings via the PPPoE protocol using the modem's web interface.

Let's examine each of these processes in more detail.

Wiring diagram

The DSL-2500U connection is typical: a splitter filter is connected to the telephone line, and a modem port labeled ADSL is connected to it. The Ethernet port connects to a computer's network card or an input on a wireless router.

The modem router is connected to the telephone line using a splitter

Connecting a modem to a telephone line

During operation, the ADSL modem transmits and receives a broadband signal with a frequency of several megahertz, therefore the connection speed depends very much on the quality of the telephone line. This is especially true of wiring in old houses, where it is made of low-quality single-core "noodles" - a low-current telephone wire of the Soviet era. If in a house / apartment several telephone sockets are connected in parallel, the connection scheme must be redone. The splitter is installed on the cable entry to the apartment, and the telephone wiring is already connected to it. If the phone and modem are connected in parallel, the Internet will not work.

Connecting a modem to a computer

If the location of the telephone socket does not allow placing the modem next to the computer, you will have to buy a patch cord of the required length or compress it yourself. Two RJ-45 plugs are crimped on a piece of UTP-8 wire in accordance with the diagram.

The cable for connecting the modem router to the computer must be crimped in accordance with typical scheme color distribution

Preparing a computer for connection - network adapter settings

Almost any router also works as a DHCP server, that is, it distributes IP addresses to client devices. Addresses are issued from the range specified in the router settings. For this mechanism to work properly, you must configure the network adapter to automatic receipt TCP/IP addresses and DNS server addresses. On computers under Windows control you may encounter a situation where a static (permanent) address is assigned to the network adapter. This may cause a conflict with another device on the network, which receives the address automatically. The result will be loss of access to WiFi networks(and the Internet too) on both devices.

To avoid such an error, you need to check the properties wireless adapter and switch (if necessary) it to automatically receive addresses.

1. Click on the "Start" button with the right mouse button and select "Network Connections" from the user menu.

   Call section network connections from the user menu

2. In the network connections window, select correct adapter and use the right mouse button to open its properties.

   Network adapter properties contain TCP/IP protocol settings

3. Select TCP/IP from the list of protocols and double-click to open its settings.

   All IP address values ​​are set in the TCP/IP protocol settings for the network adapter

4. Set to automatically obtain the network address and DNS server address, and then click OK.

   The automatic address acquisition mode is set by checking the boxes in the corresponding fields of the TCP / IP properties window

Modem web interface, configuration and access protection

After the computer's network card is configured to automatically obtain an IP address, the modem's WEB interface can be accessed at 192.168.1.1. The username is admin, and the default password is blank, meaning you don't need to enter it. To secure the network from third-party interference, change the access password immediately after initial setup modem.

Internet connection setup

After the modem is connected to a telephone line, a computer and there is access to the web interface, it's time to set up an Internet connection. We will do this using the example of the largest provider working with ADSL technology - Rostelecom.

1. Click the Add button and in the new window that opens, specify the VPI and VCI values ​​\u200b\u200bissued by the provider. If you forgot to tell them, you can clarify the necessary data by calling free line technical support. In the Service Category drop-down list, select the UBR Without PCR option.

   On the first screen of the setup wizard, enter the VPI and VCI parameters

2. Connection to Rostelecom is carried out using the PPPoE protocol. Select it from the list of protocols.

   Connection to the provider "Rosteleko" is carried out using the PPPoE protocol

3. From the contract with the provider, take the assigned to your account login and password and enter them in the appropriate fields of the settings window. Enable the Keep Alive option so that the connection is automatically restored after a connection break.

   Enter the login and password for accessing the Internet, which are specified in the agreement with the provider

4. On the WAN settings page, enable the Firewall and NAT. Be sure to check the Enable WAN service checkbox. If you plan to watch digital TV on your computer, check the Enable IGMP Multicast option. In the Service Name field, enter the name of the created connection and click the NEXT button.

   Don't forget to activate the firewall and NAT options

5. On the settings report page, check the correctness of the entered data and click the Finish button. The modem router will reboot and establish a connection with the provider, so you will have Internet in a few minutes.

   After rebooting the modem, a brief report of the settings configured will appear on the screen.

Video: D-Link DSL-2500U setup

Port forwarding

Some users need to access their local network resources from the Internet: home network folders, picture from IP home camera, remote administration Remote programs Administrator or Team Viewer and dozens more desired applications. To organize the possibility of such access, the so-called port forwarding is required, when the router combines an external network port and one of the internal ports. Setting up port forwarding is easy using the modem's web interface functions.

Setting up the modem in bridge mode

The computing capabilities of the DSL-2500U are very modest. If you use the device in router mode, then even if only one computer is connected, the programs with large quantity connections (torrent client or web server) may put excessive load on your modem. The result will be interruptions in work, and even the freezing of the device. in the best way operation will be the transfer of the DSL-2500U to the bridge mode (bridge mode) and the connection to it of an inexpensive router, for example, DLINK DIR-300.

1. Open the window with the modem setup wizard (Wizard). Uncheck the DSL Auto-connect box and enter the values ​​VPI=0 VCI=33 in the field that opens. Click Next.

   VPI and VCI parameters must be entered based on the settings of your provider

2. In the next Connection Type window, select Bridging, Encapsulation Mode - LLC/SNAP Bridging, click Next.

   Set the type of connection to the Bridging network - this will put the modem into bridge mode

3. In the next window, check the Enable Bridge Service checkbox.

   Activate the Bridge Service option

4. In the next window, if necessary, you can change the IP address of the modem. If the modem will be used in conjunction with a wireless router, set the address from the range that gives DHCP server wireless router. The subnet mask must also match.

   Enter the address to access the modem settings

5. The final window of the configuration wizard displays summary information. If all values ​​are correct, press the Save/Reboot button to save the settings and reboot the modem.

   Check the data and save the changes if everything is entered correctly

Possible problems and problems with the modem: diagnostics and troubleshooting

The DLINK DSL-2500U is a simple and reliable piece of equipment, but it can also experience failures that prevent normal operation. This is especially noticeable when buying a used modem. The table below lists common problems and their causes.

Table: Typical DLINK-2500U Modem Router Problems

A few years ago, when I was a client of the Rostelecom provider, a bunch of a DSL-2500U modem and a cheap DIR-300 wireless router worked for me. Despite the fact that the modem was in bridge mode, it got very hot and, as a result, hung up every few hours. Since the modem was already old and the warranty had ended long ago, it was decided to improve its thermal conditions by installing a cooling system. On the processor chip, I installed a heatsink from the old motherboard, and in the upper part of the case I cut out a round hole where I installed a computer cooler. The temperature of the modem dropped significantly, then it worked without failures.

A fan from an old video card will help you forget about overheating of the modem forever

The power supply (network adapter) of the modem operates in an even more severe thermal regime than the device itself. The result is the failure of the filter tanks (capacitors) in the power circuits. If you are at least a little friendly with a soldering iron, you can repair the adapter yourself. A failed capacitor is easy to find: its body will be swollen and deformed.

The first sign of a bad AC adapter is a swollen capacitor.

Video: improving the cooling of the D-Link 2500U DSL modem

The D-LINK DSL-2500 modem router is a time-tested, but very old solution, so if you only connect to the Rostelecom (or similar) network, buying it will not be a rational choice, because a bundle of a modem plus a wireless router will cost more than buying an ADSL router with wireless module. But if you live in the periphery and the state of the telephone lines or the policy of the provider does not allow you to use high-speed tariff plans, the capabilities of the DSL-2500 are more than enough. After all, as the wise ancestors wrote, old horse does not damage furrows.

The 2500U DSL modem allows you to connect the subscriber's computer to the Internet using telephone cable lines. It finds its application where laying the most modern high-speed communications is still difficult.

Based on this 2500U router, it is impossible to organize a full-fledged local network, since DSL does not have a module wireless communication. But the principles of setting up a connection between a device and a provider company are also used in more “advanced” routers.

The D-Link network device does not support many features without which the new models are not competitive in the market.

The main ones include parameters regarding the absence of:

1. built-in WiFi module to create a local wireless network on its basis;
2. USB connectors for connection external drives, mobile 3G/4G modems for wireless Internet;
3. ports for connecting with a cable of high-speed FTTx-optic fiber lines.

Appearance of DSL-2500U

Included with purchase through trading network products include:

• ADSL modem;
• splitter - a device that, when connected to an input telephone line, splits the signal into a low-frequency (analog) signal for a telephone set and a high-frequency (digital) signal used in a modem;
• two cables with RJ-12 connectors, one of which connects the splitter and the phone, and the other connects the splitter output and the DSL modem input;
• patch cord with RJ-45 connectors for connecting the output of the router to the input network card computer or laptop;
• modem power adapter alternating current;
• instruction manuals on paper and on CD.

The following items are located on the rear panel of the 2500U router:

1. DSL connector for connecting the product to the "Modem" output of the splitter;
2. LAN connector to which network devices are connected;
3. plug connector 5V=1A for AC adapter;
4. ON / OFF button (not available on all series);
5. Reset button to reset current settings to factory defaults.

The DSL front panel is designed to inform the user about the status of the communication lines of the connected equipment and individual constituent parts modem 2500U. The indicators located on the front panel of the device are as follows:

• Power indicates whether the DSL modem is powered on or off.
• Status informs about the operation of the 2500U router or errors that have occurred.
• DSL shows the synchronization status of the router in the process of working with the provider.
• Internet determines the presence of a connection with " world wide web” or the presence of critical errors in the line (red glow).
• LAN informs about the health of the communication line when devices are connected to the port.

Connecting the 2500U and Getting Ready

A telephone cable is connected to the connector of the DSL router, coming from the Modem connector of the splitter or directly from the ADSL telephone line brought into the apartment or house. The name "Asymmetric ADSL" is sometimes heard, but not entirely correct. Asymmetry is already embedded in the ADSL abbreviation in its first Latin letter (Asymmetric). The LAN connector of the 2500U modem is connected using a patch cord to the connector of the PC or laptop network card, usually built into the motherboard.

The AC adapter is connected last. The subsequent setup of the Internet connection is performed with both devices activated. The splitter does not have a separate power supply. For the 2500U router to work, it is necessary to obtain an IP address, as well as the DNS server address in automatic mode using the Internet protocol TCP/IPv4.

To configure the D-Link model 2500U modem for any provider, you need to open its interface. This is done using a PC or laptop connected to the LAN port. V address bar using the web browser that is open on the computer, you must enter the value 192.168.1.1. indicated in the enclosed operating instructions. Then press Enter on the keyboard. In the window that opens, you need to fill in the "Username" and "Password" fields.

By default, for most routers, these values ​​will be the login and password admin / admin. After that, you need to click "Login". Next - go to the main page of the interface, for different versions software firmware ( software) has its own form.

The DSL-2500U router for auto-configuration requires clicking the “Connect the Internet” tab (Quick Setup, Wizard) on home page interface. The DSL modem is configured using the Setup Wizard. It requires data received by the user from the provider. Setting up the 2500U is, in fact, semi-automatic, since at various stages of its implementation it is necessary to manually enter data from the contract. To proceed to the next step, click on the "Next" stencil.

There are many versions of the 2500U modem. From here you can see the variety of WAN interfaces. The first step is to select the connection type: PPPoE, PPPoA, IPoA, IPoE, Static IP, Dynamic IP, Bridge.

When continuing the DSL setup in sequence, you will need to additionally enter the values ​​of the VPI, VCI parameters, depending on the region of the operator providing the services.
For PPPoE, PPPoA connections, a username and password provided by the ISP are required. They remain unchanged. They are entered only when setting up the 2500U and are saved when the equipment is turned on again.

Static IP requires the entry of an Internet address (paid) assigned by the provider, which remains unchanged throughout the entire territory of the operator. Dynamic IP does not require any action on the part of the user when setting up an Internet connection.

Connecting to the Internet manually using some providers as an example

At manual setting it is possible to configure the 2500U modem for the user and set all the necessary parameters, without excluding those that are required without fail for the type of connection of each of the Internet operators. On the DSL modem administration page, go to the Advanced Setup tab.

"Home ru"

After entering the advanced settings of the 2500U router, click on the "Network" tab in top row and enter its menu. Then select the WAN partition, click "Add". The operator uses PPPoE-. It must be selected from the proposed list.

In the fields "Username", "Password" and "Password Confirmation" it is necessary to write down the data received from the provider and specified in the contract. You must check the Keep Alive box.

Find out the values ​​\u200b\u200bof the VPI and VCI indicators by calling the provider. They must be entered in the appropriate fields.

This operator additionally uses binding to the MAC address of the equipment used. This address is an identifier physical device assigned to it during production. Before setting up the 2500U, it must be reported to the provider. The address information is located on the label of the DSL modem, located on the bottom of the case. It is a sequence of 12 digits and Latin letters and is designated MAC ID.

If there is no address on the label, the information is available in the advanced menu. To do this, in the top row of tabs, click on “Start” (Device Info). For router firmware version 1.0.50, the physical address is designated LAN MAC.

After filling in the required fields, click on "Save". The Internet indicator on the front panel of the device should light up after saving the configuration in an average of 20-30 seconds.

In the WAN tab, select the Home section, and click ADD (“Add”) in it. On the page for creating a connection, enter the VPI, VCI data from the agreement with the regional provider Rostelecom, and in the Service Category column, select UBR Without PCR from the list. To continue, click Next.

On the next configuration page, check the PPP over Ethernet checkbox and click Next.

After that, in the PPP Username and PPP Password fields, you need to enter information about the username and password from the contract. And also check the Keep-Alive item. The last action saves the connection in case of an accidental loss of communication and its subsequent restoration. Then click Next to go to a new page.

Here, check the items: Enable NAT, Enable Firewall, Enable WAN Service. V last paragraph O after-sales service write Rostelecom.

After clicking on Next, you will be redirected to the summary page. After checking its compliance with the previously entered values, click Finish. It is now possible to control the connection signaling on the Internet indicator on the front panel of the DSL modem.
In more detail, we analyzed the details of the settings in the article.

"Beeline"

This operator assumes that the user is using equipment that supports an L2TP WAN connection. The 2500U modem in question has technical specifications the following types of connections are specified:

• PPPoA.
• PPPoE.
• IPoA.
• IPOE.

The connection of the Beeline operator for the DSL router is not provided. It is supported by the manufacturer "D-Link" in models of a later release, for example, DIR-300.

NetByNet

On the main page of the interface, in its menu, the transition to the connection settings is made by selecting the WAN tab, and in it - the Home section. The connection is created by clicking on ADD. The new page allows you to select the type of connection from the contract. The 2500U modem in question is available for a PPPoE connection when obtaining a network address in automatic mode and PPPoE with a static address received from the provider.

In both options, the subscriber's contract contains a username and password. They must be entered in the appropriate fields. The entered password must be confirmed in the corresponding field.

After that, you need to check the item "Clone address". In this case, the provider will see the MAC address of the computer with which the DSL modem works. Always is written in the mode selection field. In this case, the connection will be stable when possible failures over the line of communication. The entry is completed by clicking on the Next stencil.

On the new page, you need to check the items: Enable Firewall, Enable NAT.

In the case of a PPPoE connection with a local (static) IP address, you must additionally check the Static IP box.

In this case, after clicking Next, a page will open where you need to fill in the fields with data from the contract: the address assigned by the provider, the subnet mask, the gateway used, the preferred and alternative addresses of DNS servers.

The entered information is saved after pressing the Save Settings button. On the next page, you need to control the data of the created connection reflected on it. If their values ​​are correct, click the Finish stencil. After a while - no more than 20-30 seconds - the Internet indicator on the front panel of the 2500U router should light up, which will confirm the connection with the provider.

Bridge operation mode

With the listed providers, the DSL modem works only in router and transparent bridge modes. Repeater (repeater), amplifier, adapter or access point modes are not available to him.

If, with the settings set and saved, you need to use the 2500U modem in bridge mode, this will not cause difficulties. To do this, go to the "Configure manually" tab by clicking on it with the cursor. On the page, go to the WAN section, and in it - the Home subsection. In the created connection, adjust its type: PPPoE to Bridge, leaving the rest of the settings unchanged.

Additionally, "Encapsulation type" and service category are added. The first option is set to Bridged IP over ATM LLC SNAP and the second option is set to UBR.

At the last step, click the Finish stencil. After such a change, the DSL router only performs the function of transferring information from the telephone line to the computer and vice versa.

In bridge mode, the 2500U router works with only one computer in general. But the considered DSL model initially has only one LAN connector. The built-in firewall stops working. protection from network attacks takes over the computer. Network Address Translation (NAT) stops working and the printer stops working.

IPTV

For TV box needed to work interactive television, you need to allocate a separate LAN port. IPTV receives the stream of information directly from the provider. On other router models, the dedicated port is programmatically switched to transparent bridge mode and can no longer be used for other purposes. The 2500U modem has only one LAN port and the user has to decide on a priority connection. The question is about changing settings.

Bridge connection is required for IPTV to work. It is necessary to set the values ​​of the VPI and VCI parameters from the contract in the WAN section.

In the "Miscellaneous" section of the settings, check the "Enable IGMP" item. After that, the port is "given away" for IPTV.

Parental control

This setting is in addition to the basic functions of the 2500U. On the administration page, click on the "Configure manually" tab. In the top menu of the tabs that open, select "Control", click on it.

After clicking on "Add", it becomes possible to create a new rule. The local network for the DSL modem in question consists of only one computer, so only one rule is created.

It indicates the MAC address of the PC, prescribes an arbitrary name and puts a mark in the “Enabled” item. After that, a schedule is drawn up, which includes the days of the week, hours, minutes of the beginning and end of the opportunity to work.

In the "URL filter" section, you can block/allow the operation of sites specified by the user. Port 80 is selected. The settings are completed by clicking on "Save".

Dynamic DNS

The setting in the DSL of this parameter refers to the advanced version of the routing settings. Access is made by clicking on the "Advanced" tab. Dynamic DNS (DDNS) comes into operation in dynamic IP mode, allowing each change of address - in digital form - to leave a permanent domain name.

Security settings (antivirus, firewall) on the 2500U modem

Access to the security settings in the DSL modem is provided from the main menu when you select the "Firewall" (firewall) tab. Here you create IP filtering rules for dangerous and working addresses. To create a new rule, click on the "Add" stencil. Here are created virtual servers and DMZ zones (virtual server dmz). They are able to redirect all Internet traffic to a specific IP address on the local network.

Possible malfunctions and ways to eliminate them

All problems that occur during the operation of the 2500U DSL routers are divided into the following groups:

• consumer equipment software;
• hardware part of the system;
• service provider faults.

In the first case, it is necessary to separate the situations when they arise on initial stage settings, and failures that appeared during the operation of the DSL modem. At the initial stage, setting up the 2500U must be carried out with strict observance of all the requirements of the manual, the sequence of operations, saving the entered data at each stage. After finishing the DSL setup process, you need to check the received totals.

The causes of failures that occur during operation of the 2500U are often external factors: sudden power surges or thunderstorms. Great help in these cases will be the use of uninterruptible power supplies (UPS) with an autonomous battery (battery). If it is impossible to continue DSL operation, it is necessary to reset its settings to the factory values ​​using the 2500U router. And also to carry out work on the restoration of previously entered data. Firmware firmware will be of great help to latest version ON.

The indication of the DSL modem on the front panel will help in troubleshooting the hardware (“hardware”). The exception is when the Power LED is off. For this option, replacing the AC power adapter is useful. It is necessary to check the serviceability of the wires and measure the voltage with a multimeter. It will be useful to examine all cable connectors for their reliable connection and check the health of the communication lines of the system equipment. In the absence of Internet information, sometimes the PC is “guilty”. If it is possible to check this version, it can be temporarily replaced.

After the verification activities carried out, the consumer of services should call the operator's technical support service and report the problem. In the case of normal operation of the provider's equipment, the assistance of warranty or repair shops is required.

DSL Router Firmware Update

Updating the 2500U router, that is, the version of its software, is required when numerous problems accumulate. Before starting the DSL firmware, you need to carefully study the stickers on the product case, determine the version of its hardware (H / W) or the type of revision. As well as the software version (S/W) at the time of release. S/W version or line type are: annex a, annex b. And the revision is A, C, D.

On the site www.dlink.ru, you need to download the latest file from the Firmware folder from bin extension, save it to your computer.

On the main page of the interface, go to the "System" tab. In it, select the “Software Update” item, on the new page, click the “Browse” button. After finding the downloaded file, click on the "Update" button to install the new 2500U router software. At the end of the update process, the computer will automatically restart and return to factory settings. It is necessary to re-configure the DSL router using the technology described above.

Resetting the router 2500U to factory settings

The DSL modem has a hardware and software reset. For hardware reset of the 2500U router settings to the factory values, a Reset button is recessed into a narrow socket. Its thin rod must be pressed and held for 10-15 seconds. After that, you need to wait for a minute for the blinking to stop. The factory settings will be restored.

For software reset in 2500U, after entering the administration page, click on the "Manually configure" tab. On the new page, hover over the inscription "System" in the upper right corner, click it and select "Factory settings". By clicking on the item, start the process of restoring the original values, followed by an automatic reboot of the DSL router.

Conclusion

An overview of the D-Link DSL-2500U router shows that the model is used where there are only ADSL telephone lines, through which the Internet can be transmitted at a satisfactory speed. DSL is a budget entry-level device. Based on it, it is impossible to organize a local network. The principle "One modem - one computer" applies here. The history of the 2500U modem has more than 10 years. DSL has rightfully earned a "deserved retirement".

pros

The positive qualities of DSL include:

• the 2500U has a relatively easy setup process with the ability to quickly return to the original values ​​​​in case of an error;
• the possibility of using DSL in telephone lines with a high level of interference;
• the presence of a large base of components for the repair of the device.

Minuses

The negative qualities of the 2500U today are:

• lack of a wireless communication module, USB connector;
• the presence of only one network port;
• obsolete element base leading to frequent failures in work;
• low speed of data exchange in the network.