Three ADSL modem. Outside, inside, and their internal OS
It so happened that at the same time I had three ADSL modems from different companies at once. Under the cut there are photos of all three devices both outside and inside, as well as a little about the internal operating systems of the modems and their firmware. The article does not contain any conclusions and screenshots of modem's web interfaces.
This modem should be familiar to many, I suppose. They connected almost all users of MGTS and Stream; even once when connected, they “gave” this modem for free. I am no exception, and I got this modem in this way. The modem looks quite simple, everything is “standard” - a hole for RJ-11 (telephone wire), a hole for Ethernet, light bulbs on the front panel: There is also a USB output, which means that the modem can be connected to a computer either via Ethernet or via USB .
By the way, not many people know that two computers can be connected to this modem at once simultaneously. One computer - via USB, the second - via Ethernet. To do this, just need to register in the TCP / IP settings on a computer connected via USB, the IP address is 192.168.100.2, for example. But I got a little distracted. Let's take a better look at the modem's PCB:
')
View a huge picture
The modem is built on a Broadcom BCM6338 chip with a frequency of 240 Mhz and MIPS architecture. It has 8 Mb of RAM, represented by the Hynix chip, and 16 megabytes (2 Mb) of flash memory. The use of the BCM processor in the modem gives hope that the internal operating system of the modem will turn out to be nothing more than a stripped-down copy of Linux. Something similar to the one used in the famous ASUS WL-500GP router. And indeed, going with telnet to 192.168.1.1 we see the following picture:
Familiar teams, right? But something is missing, for example, you cannot view the list of files with the ls command. Here a little ingenuity (or Google) comes to the rescue - we enter the sh command, and voila. We get into BusyBox. The set of commands is also limited, but now you can take a look at cpuinfo, for example:
Naturally, you can change the settings, see how much memory is used, restart the device. Everything is made convenient for a person who is slightly familiar with Linux. The structure of directories and configuration files is approximately the same as that of the ASUS WL-500GP router, as well as other network hardware on Broadcom chips.
You can add that the modem hardware coincides with the TP-LINK 8811 modem, so you can safely flash it with the TP-LINK firmware. As a bonus, we get DynamicDNS and, possibly, support for some additional protocols (firmware for TP-LINK comes out much more often than firmware from ZTE).
The size of the modem is about the same as that of the ZTE. It also looks like - in front of the LEDs, behind the hole. The only visual difference is that the modem does not have the ability to connect to the computer via USB, only Ethernet, and therefore the ability to connect two computers to the modem at the same time without using a switch is no longer possible. Appearance:
Configuring a modem is not difficult with the help of a wizard, and has all the same functions as ZTE, except that only DynamicDNS is present out of the box. However, the filling differs significantly:
View a huge picture
When I wrote these lines, I discovered that this modem has an older twin brother P-660RU EE, which is described in detail in the article http://www.thg.ru/network/zyxel_p-660ru_ee/print.html . They differ only in the presence of USB-out. Therefore, further I narrate in a somewhat compressed format so as not to repeat what has already been written.
The modem is built on a TRENDCHIP TC3162L-LQ128 processor, information about which is scarce. Presumably, this is a 32bit MIPS RISC processor with a frequency of 200 Mhz. The second chip deals with ADSL and USB, which, if you look closely, is not soldered on the board. Here we see the 8 Mb of memory standard for this class of modems represented by the Winboard microcircuit. Flash memory is located on the reverse side of the PCB, apparently due to the lack of free space and is all the same 16 megabits (2 Mb).
View a huge picture
The modem's operating system is called ZyNOS and is an explosive mixture of Zyxel and Cisco IOS own developments, I think. First, the user enters the text menu, but from paragraph 24.8 it can enter the CLI command line mode. Initial menu available to the user:
Here you can also change settings, display various information and control the device using the menu. From the point of view of a user who is not dedicated to the wisdom of Linux, this approach is more convenient. But take a look at command mode:
Zyxel uses a similar operating system in its other SOHO devices, for example, P-330W EE routers. But here, without first reading the documentation, everything is not so intuitive. And it seems like not Cisco IOS and not like Linux-based. On the other hand, the OS is interesting precisely by this - the difference from other OS.
A few words about the firmware: in general, the modem is flashed as standard via the web interface. But it still exists separately from the versions of the firmware versions of the boot loaders, which are only flashed through the tftp command. On the Russian support site, apparently so as not to torment ordinary users, only firmware is available, while both firmware and loader are available in English. For example, I downloaded the latest firmware for the P-660R-T1 from the English version of the site, took only the loader from there (file with the .rom extension), then logged in with a telnet in one window, switched to the CLI mode (item 24.8 of the menu) and the “sys stdio 0” command to prevent the console from logging out after a timeout. Further in another window we write the command: “c: \ tftp -i [PrestigeIP] put [localfile.rom] rom-0”. Then you can flash through the web interface the latest native firmware from the Russian site ...
This modem differs from the previous ones by the presence of a Wi-Fi module and also has five Ethernet ports. Naturally, the size of the device increased in length:
The web interface has added settings for Wi-Fi ... Since the modem does not have control via Telnet. Let’s just look at the schematic technique and conclude this article with this:
View a huge picture
The modem is built on the basis of the Infineon PSB7200 chip, this is the former TNEDT7200A company TI. The clock frequency of the core is 212 MHz. It has 16 Mb RAM on the EtronTech chip and 4 Mb of flash memory.
UPD: Hmm, as it turned out, he's called Level One WBR-3460A aka NetGear DG834G v3.
It also turned out that it is managed by the Linux kernel with the OpenBox.
Thank you all for your attention.
Patient # 1: ZTE 831 A II
This modem should be familiar to many, I suppose. They connected almost all users of MGTS and Stream; even once when connected, they “gave” this modem for free. I am no exception, and I got this modem in this way. The modem looks quite simple, everything is “standard” - a hole for RJ-11 (telephone wire), a hole for Ethernet, light bulbs on the front panel: There is also a USB output, which means that the modem can be connected to a computer either via Ethernet or via USB .
By the way, not many people know that two computers can be connected to this modem at once simultaneously. One computer - via USB, the second - via Ethernet. To do this, just need to register in the TCP / IP settings on a computer connected via USB, the IP address is 192.168.100.2, for example. But I got a little distracted. Let's take a better look at the modem's PCB:
')
View a huge picture
The modem is built on a Broadcom BCM6338 chip with a frequency of 240 Mhz and MIPS architecture. It has 8 Mb of RAM, represented by the Hynix chip, and 16 megabytes (2 Mb) of flash memory. The use of the BCM processor in the modem gives hope that the internal operating system of the modem will turn out to be nothing more than a stripped-down copy of Linux. Something similar to the one used in the famous ASUS WL-500GP router. And indeed, going with telnet to 192.168.1.1 we see the following picture:
Familiar teams, right? But something is missing, for example, you cannot view the list of files with the ls command. Here a little ingenuity (or Google) comes to the rescue - we enter the sh command, and voila. We get into BusyBox. The set of commands is also limited, but now you can take a look at cpuinfo, for example:
Naturally, you can change the settings, see how much memory is used, restart the device. Everything is made convenient for a person who is slightly familiar with Linux. The structure of directories and configuration files is approximately the same as that of the ASUS WL-500GP router, as well as other network hardware on Broadcom chips.
You can add that the modem hardware coincides with the TP-LINK 8811 modem, so you can safely flash it with the TP-LINK firmware. As a bonus, we get DynamicDNS and, possibly, support for some additional protocols (firmware for TP-LINK comes out much more often than firmware from ZTE).
Patient # 2: ZyXEL P-660RT EE
The size of the modem is about the same as that of the ZTE. It also looks like - in front of the LEDs, behind the hole. The only visual difference is that the modem does not have the ability to connect to the computer via USB, only Ethernet, and therefore the ability to connect two computers to the modem at the same time without using a switch is no longer possible. Appearance:
Configuring a modem is not difficult with the help of a wizard, and has all the same functions as ZTE, except that only DynamicDNS is present out of the box. However, the filling differs significantly:
View a huge picture
When I wrote these lines, I discovered that this modem has an older twin brother P-660RU EE, which is described in detail in the article http://www.thg.ru/network/zyxel_p-660ru_ee/print.html . They differ only in the presence of USB-out. Therefore, further I narrate in a somewhat compressed format so as not to repeat what has already been written.
The modem is built on a TRENDCHIP TC3162L-LQ128 processor, information about which is scarce. Presumably, this is a 32bit MIPS RISC processor with a frequency of 200 Mhz. The second chip deals with ADSL and USB, which, if you look closely, is not soldered on the board. Here we see the 8 Mb of memory standard for this class of modems represented by the Winboard microcircuit. Flash memory is located on the reverse side of the PCB, apparently due to the lack of free space and is all the same 16 megabits (2 Mb).
View a huge picture
The modem's operating system is called ZyNOS and is an explosive mixture of Zyxel and Cisco IOS own developments, I think. First, the user enters the text menu, but from paragraph 24.8 it can enter the CLI command line mode. Initial menu available to the user:
Here you can also change settings, display various information and control the device using the menu. From the point of view of a user who is not dedicated to the wisdom of Linux, this approach is more convenient. But take a look at command mode:
Zyxel uses a similar operating system in its other SOHO devices, for example, P-330W EE routers. But here, without first reading the documentation, everything is not so intuitive. And it seems like not Cisco IOS and not like Linux-based. On the other hand, the OS is interesting precisely by this - the difference from other OS.
A few words about the firmware: in general, the modem is flashed as standard via the web interface. But it still exists separately from the versions of the firmware versions of the boot loaders, which are only flashed through the tftp command. On the Russian support site, apparently so as not to torment ordinary users, only firmware is available, while both firmware and loader are available in English. For example, I downloaded the latest firmware for the P-660R-T1 from the English version of the site, took only the loader from there (file with the .rom extension), then logged in with a telnet in one window, switched to the CLI mode (item 24.8 of the menu) and the “sys stdio 0” command to prevent the console from logging out after a timeout. Further in another window we write the command: “c: \ tftp -i [PrestigeIP] put [localfile.rom] rom-0”. Then you can flash through the web interface the latest native firmware from the Russian site ...
Patient # 3: TRENDnet TEW-435BRM
This modem differs from the previous ones by the presence of a Wi-Fi module and also has five Ethernet ports. Naturally, the size of the device increased in length:
The web interface has added settings for Wi-Fi ... Since the modem does not have control via Telnet. Let’s just look at the schematic technique and conclude this article with this:
View a huge picture
The modem is built on the basis of the Infineon PSB7200 chip, this is the former TNEDT7200A company TI. The clock frequency of the core is 212 MHz. It has 16 Mb RAM on the EtronTech chip and 4 Mb of flash memory.
UPD: Hmm, as it turned out, he's called Level One WBR-3460A aka NetGear DG834G v3.
It also turned out that it is managed by the Linux kernel with the OpenBox.
Thank you all for your attention.
Source: https://habr.com/ru/post/85225/
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