This information is provided based purely on my knowledge of using the Airtel broadband plan for over a year. Please contact me if you think any information is invalid, outdated or missing.

Contents

1. Introduction

2. Router Configuration

i. What are ports?

ii. Procedure

3. Known Issues with Airtel Modems and Routers

i. Zyxel USB Modem

ii. D-Link DSL-502 T

iii. Beetel Broadband Router

4. Driver Installation

1) Introduction

Airtel offers a great plan for Unlimited broadband internet connection in some states :

Option A: Rs.699 a month for 128 kbps Unlimited

Option B: Rs.999 a month for 256 kbps Unlimited

The Beetel TERA 100 U Modem

There are no limits on download, no blocked ports (as far as I know), and no internet filters to prevent anyone from visiting any site. The service is generally reliable, with a decent uptime of more than 90%. The plan comes with a modem, which is usually one of the following:

• Zyxel (blue color)
• Beetel TERA 100 U (distributed by Yozan)
• Beetel 100 CX

All these 2 are USB modems with only one computer connection. If you are using Linux, BSD or x64-bit Windows; there are no drivers for the above modems to work on these OS. So, ask for one of the below routers instead:

• D-Link ASDL Router DSL-502T
• Beetel Broadband Router

The routers are provided instead of the modem and at no extra charge. The router has 2 outlets: a USB connection and an Ethernet connection. So, those on Linux/BSD/Windows x64 should use the Ethernet connection. As Airtel keeps changing their modem variety often, you might get some other newer type of modem/router too. I would advise to ask for the router anyway since it has more control over internet traffic. It also allows 2 simultaneous connections and hence can be used for sharing an internet connection. The router however requires some configuration (e.g. port forwarding) if the user wishes to uses file sharing programs, IRC etc. Those unwilling to invest the extra effort should just go for normal USB modems.

I have provided below some drivers for the modems / routers. All of these are Windows-32 bit drives.

Beetel TERA-100U Drivers (v.040303OC)

Beetel 100 CX Drivers (v.099.074)

Note : You will need a archiver that can open .7z formats. Try 7-Zip.

2) Router Configuration

The Airtel staff will usually set up the internet for you initially, but won't configure the router to allow port forwarding. Port forwarding is necessary for several internet applications and file sharing programs to work with.

i) What are ports?

Your computer has several ports through which applications connect to the internet. There are a total of 2^16 = 65,536 ports. An application may need to use one or more ports when it is running. Through the ports, it will send and receive data from other computers on the net. Applications cannot share a port while running at the same time. An exception is HTTP Tunneling, see Corkscrew. It is however widely acknowledged that certain ports are associated with certain applications. For example, port 80 is used for HTTP (i.e. your connection to the WWW), port 21 is used for FTP and so on. You can find an entire list of ports and their associated applications here : IANA List of Well Known Ports

As you can see, a large number of ports are actually unassigned to any application. This is for future use, when more internet applications may come about.

By default, when you set up a router for internet connection, most ports, except port 80, are blocked. This is actually a good thing since open ports are a favorite target of crackers trying to break into your computer. On normal modems and internet connections, you can use a program like Port Blocker to close unused open ports. On a router, you have to identify which ports you want to open first and then do port forwarding to open those.

ii) Procedure

First run the application (e.g. mIRC or File Sharing Program etc.). If it connects with no problems, then you're set. Many file sharing programs (e.g. Azureus, Bitlord, eMule, DC++ etc) usually have a inbuilt test feature that can test your connection to the internet. Run this test as well just to make sure that the connection is okay. If you are unable to connect properly or the test fails, then you probably have to port forward.

Next, look at the Help files/ FAQ/ Documentation of the application. This will usually list which ports are used. You can also look at the list of ports and applications, but it may be outdated. Take note of whether the port is a TCP or UDP port. Next, start up your web browser and type 192.168.1.1 into the address. This will usually be the address of the router. You will then get a prompt box or be led to a page which asks for a username and password. Check your router manual for the default username and password. It will usually be Username: admin and Password: admin

If this doesn't work, someone who used the router before you might have changed the password. Just look for a small button on the router that says reset. This will let you default back to the factory settings. Once you log into the router, you will be presented with a page for navigating around. Switch off DHCP and then add your computer's IP address to the LAN clients. You also have to turn off Dynamic IP Assignment on your computer. In Windows 2000/XP this is found under TCP/IP Properties for your LAN connection. In Linux, look for a graphical network configuration tool. This is found in Gnome or KDE quite easily. For other Window Managers, refer to your specific documentation. Usually Linux lets you specify the setting during install as well, if you have yet to install it.

Next, you have to create rules for port forwarding. Look for a page like Virtual Server or so which lets you create specific rules. Add the port number to the list and choose whether it is TCP or UDP or both. For some applications, you can use any port you want. In that case, look for a port that is not used by any other application and add it. You will also have to go to the settings section of that application and set it to use the same port number.

After the rules are made, click apply. There will usually be an option to export the setting as a config.bin file, make sure you do this because if the router settings get corrupted or reset, at least you can restore the old rules without having to do it all over again.

* For a detailed procedure of port forwarding for your router, see Port Forward.

3) Known Issues with Airtel Modems and Routers

i) Zyxel USB Modem

This modem seemed somewhat susceptible to overheating and a few folks complained that it often went bust during a lightning storm. Other than that, it seems okay.

ii) D-Link DSL-502 T

The D-Link DSL-502 T router tends to lose all the stored settings if the power goes off. The solution is to export the settings as a config.bin once rules are made. When power resumes, the router will know where to go and look for the config file and will automatically restore the settings.

Occasionally, the ADSL Link/Acct light will go off. The solution is to switch off the modem, wait for 10 seconds and then turn it on again so that it can find the connection back. There may be a problem with the ADSL splitter if this happens too often, ask the Airtel technicians to take a look.

An ASDL Splitter

iii) Beetel Broadband Router

This router has a nasty user interface and one could never quite figure out how to port forward using this. It also seems that it fails to do its job as a router (as far as security is concerned) since it allowed all outgoing and inbound connections on all ports. I could never figure out how to add more clients to the LAN or block open ports, except using Port Blocker. The hardware does have a nice exterior though.

4) Driver Installation

All the Airtel USB modems need to have their drivers installed only through the CD Auto run Installer. Trying to use the Device Manager to look for drivers on the CD usually fails. Should it otherwise succeed, the user still has to manually create a new connection etc. The Beetel 100 CX is probably the best modem as far as driver installation goes, it is painless and error free to install and uninstall.