Monday, January 1, 2001		Lead Article

TIME changes very fast and so do the technologies and concepts associated with it. When we were children, we used to get impressed by speeds expressed in kmph (kilometres per hour). However, now the terms of reference regarding speed have changed and today one talks of speed in terms of kbps (kilobytes per second). In some advanced countries, it has crossed even the barrier of kbps! They talk of it in mbps (megabytes per second).

Do you have any doubts about what these speed benchmarks are related to? Well, they are the benchmarks for cruising on the information highway. This speed is related to the data transfer rate, which you get by connecting your computer through a modem, either with another computer, network, or the Internet. In other words, these terms are associated with the Internet

Normally when we connect to the Internet, the average speed of connection is 28.8 kbps. Though at the time of connectivity, it may show the Internet connectivity at higher rate, but on an average the speed hovers at 28.8 kbps. Moreover, people having the same ISP can also have different ones, depending upon the state of their phone lines and also the number of analog switch between their modem and telephone exchange. Thus, if the number of analog switches is more then the data transfer rate would drop and the overall speed would be lower.

Now a question arises: Given the constraints of telephone exchanges and also the fact that the data transfer rate on analog lines cannot go beyond 56 kbps, how the speed of the Internet connection could be boosted up using the normal set-up comprising PSTN line (normal telephone lines) and analog modems?

Although with the advancement, new methods of Internet connectivity, like DSL, ISDN, cable modem and xDSLare are fast becoming popular, yet they still have a long way to go, as the cost associated with these is quite high. Moreover the availability of these services is also restricted to a few cities only. Thus, in all such circumstances, the only solution for having better Internet performance within the given situation is high-speed analog solution. Under this solution you can combine the power of two modems to boost the overall Internet experience. By combining two modems, you can effectively increase the overall bandwidth of Internet connection, though it may not necessarily double in all cases. Theoretically you can achieve the speed of 112 kbps, by combining the bandwidth of two 56 kbps modems. All you need for using this method are two telephone lines, two 56 kbps modems and two Net connections. It is not necessary that you necessarily have both 56 kbps modems. You can also use lesser speed modems and converge them for better bandwidth, but the optimum results could be obtained only from 56 kbps modems.

A user cannot achieve better bandwidth simply by connecting two modems to computer and dialling separately to different ISPs to browse the Net on the same computer. For this purpose you will need some specialised services and software solutions.

These solutions can broadly be categorised as modem bonding and modem teaming.

Modem bonding: Modem bonding is an ISP-based solution and it uses the Multilink Protocol Plus (MP+) technology. Under this technology, data packets from the Internet are inverse-multiplexed through the two modems; that is, each modem receives half of the packets and are recombined in the computer. This technique was derived from the channel bonding principle, used in ISDN connections.. Usually if we combine two telephone lines to access the Net, both the lines get busy. However under this technology, you can disconnect one modem at a time and still maintain the Internet connectivity. The surfer can keep the call waiting on one line and when she gets a call on that line, it automatically get disconnected without affecting the Internet connectivity as the bandwidth in case of disconnection is switched over to the other modem. In case of disconnection, the overall bandwidth will reduce to half.

This solution needs support from the ISP. Thus, you can use the Multilink Protocol Plus technology, only if the ISP supports this service. It also requires an account on the ISP that can be logged on to twice as two separate accounts or two separate ISPs will not work with modem bonding. In order to avail this service you need to talk to your ISP about it as in our country, though many ISPs have support for it yet they have still not enabled it. However, if you have support for multi-linking, then you can easily set this feature up in your computer. Multi linking is the option, which was added in the Windows ’98 SE edition and the previous versions may not support it. Those persons, who are using the older version of Windows, can download Dial-Up Networking v1.3 or later for using this feature. In order to activate Multilink for a dial up connection, you must simply edit properties, by locating it in dial-up networking in My Computer. When you right click on Properties, a new Window will open on the computer. Click on the Multilink Tab and select "Use Additional Devices". Now press the Add button. While connected, extra connections can be dynamically added or dropped by double-clicking on the Connection icon, pressing Details, and using the Suspend/Resume button. To make a Multilink connection, just double-click on connection icon in the Dial-Up Networking window. When you do, you’ll see the initial Connecting To dialog box as you normally would. After the initial connection is established, you’ll hear the second modem begin dialing the second connection. As soon as Dial-Up Networking establishes the second connection, double-click the Connection icon in the system tray. When you see the Connected To dialog box, select the Details button to expand the dialog box, so that you can see all details. Now you are all set to derive a bandwidth of up to 112 kbps depending upon the line conditions and also the fact that your ISP supports Multilink Protocol Plus technology.

However, if your ISP does not support the MP + technology, do not lose heart. There are still good solutions available for boosting up the Internet performance.

The next solution is for all such cases where the MP + is not supported by ISP. This solution is effective and is termed as Modem teaming.

Modem teaming: Modem teaming is like modem bonding except for some basic difference. In case of modem teaming, the support of MP + technology from the ISP is not required. Even if your ISP does not support MP + technology, you can still use modem teaming software. Second, in case of modem teaming it is not necessary that same ISP connects one through dual login. You can use two ISPs of your choice or can even log in with the same ISP with two different accounts. Rest in both options you will require two telephone lines and two modems. However in case of modem teaming the task of converging two modem to one computer is being done by specialised software. This software is being provided by midpoint software and you can download the trial version from www.midpoint.com. However talking in terms of technology Modem teaming is inferior to modem bonding in terms of functionality and speed, but is a good alternative for users who do not have an ISP that supports MP + or cannot use modem bonding for any other reason. As against the modem bonding, which uses MP+ technology, modem teaming uses the technique called File splitting. Using this capability, the modem teaming software instructs one modem to download the first half of a file, while the other modem downloads the second half. This reduces the download time by half and thus boosts the Net speed.

Normally most of the files can be downloaded by splitting, but just in case any file can not be downloaded in split mode, then in all such cases a modem teaming connection is only as good as one modem. Moreover for the purpose of modem teaming, you need to connect to the Internet through a proxy server, which is essential for converging the two modems under modem teaming.