How to get a faster data connection

Not all of us have access to high speed data technologies such as ADSL or Cable Modems, and for those of us that do, we can't always guarantee reliability when we need it. 56kbps connectivity just isn't enough for a lot of applications, but if analog is all that is available, there is a way of increasing that bandwidth effectively.

To get more than 56kbps, you can use multiple analog lines and multiple modems to create what looks like a single high bandwidth connection! There are two ways of doing this, usually known as Line Bonding and Connection Teaming.

Line bonding is where both ends of the connection have the right software installed, and multiple modem connections get 'bonded' together to act as one big connection. Recent Microsoft Windows* and Linux* operating systems support this without having to buy any other software, but it must be supported by your Internet Service Provider (ISP).

Connection teaming allows you to connect using multiple lines without requiring support from the other end. In fact, you can connect using different ISPs for resilience. With some packages you can use lines for different functions, so you could send/receive a fax or make a call on lines not in use. The drawback is that this requires a 3rd party software package to support it.

With both of these types of solution, you can implement 'bandwidth on demand' where extra lines are only dialled up when there is a need for them, based on rules you set. This can be particularly useful if you only require high bandwidth for short periods.

Hardware requirements

In each case you will require more than one modem installed and more than one telephone line. It is possible to use several individual modems connected to the PC. However, we recommend using server-grade multi-modem cards to minimise your installation issues, and to maximise your reliability and speed. The modems you choose should support V.92 connectivity to make the most of the telephone lines, and to reduce connection times.

The hardware should also support modem-on-hold, which allows you to suspend a data connection on a particular line and take an incoming call, and then resume the data connection afterwards. This means that all your lines can be connected for data, but you won't miss a voice call or fax.

Line Bonding Connections

The method that is used for this type of connection is known as MultiLink PPP (Point to Point Protocol), MPPP or modem aggregation. This is supported by a lot of ISPs, but may not be an advertised service. If it is not supported by the ISP, it cannot be used, as software is required at both ends to associate the separate connections together.

Multilink PPP on Microsoft Windows*

Since 1998 this has been a part of the Microsoft Windows* operating system. Once you have a multi-port modem installed in your system, and the requisite number of phone lines connected, you can configure a particular internet connection to use multiple lines. You can also use the Bandwidth Allocation Protocol (BAP) to define how and when more lines are added to a connection dynamically.

You can also use the server versions of Microsoft Windows* as a Remote Access Server (RAS) accepting Multilink PPP connections. That way you can offer remote users access to a corporate network at speeds higher than 56kbps or you can securely link two sites using modems on demand, rather than costly leased lines.

Microsoft provide several detailed documents that guide you step by step on setting up Multilink PPP:

Windows XP*:
- 307849: HOW TO: Set Up Multiple-Device (Multilink) Dialing in Windows XP
Windows 2000*:
- 235610: Overview of Multilink and Bandwidth Allocation Protocol (BAP)

Up to date information on a specific version can be found by searching the Microsoft Knowledge Base at http://support.microsoft.com

Multilink PPP on Linux*

Setting up Multilink PPP can be quite involved if things do not work immediately. Linux kernel versions 2.4 and later include support Multilink as part of the pppd daemon natively, although it may be an optional compile-time option. Linux systems may be configured as either a Multilink client or server.

If you specify the multilink option when using pppd, then it will detect if a bundle (i.e. an existing connection) is in place with that host already. If not, it will create one, and subsequent instances of pppd can then make separate connections, but bundle them together with the first one. It is important that the bundle identifiers are the same for this to work and both ends are able to identify two connections as part of the same bundle. This should happen automatically, but may be worth checking if the connection is not working. If the first connection is lost, this may cause the entire bundle to be terminated.

More information on this can be found in the 'man' pages for the pppd command, or in documentation for your specific Linux* distribution. You can also find lots of information on The Linux Documentation Project website, although this information is not always up to date.

Connection teaming

Connection teaming provides several distinct advantages over the 'native' operating system capabilities. Support from the server end is not required, as the teaming software acts as individual connections and uses some tricks to make use of the extra bandwidth.

You may also be able to dynamically allocate a line to a particular function, such as fax, voice, remote access or Internet connectivity. In this way, you can efficiently use multiple lines for whatever is required at that point, rather than dedicating lines to a particular function. You may also be able to specify a particular destination for mail or web access, so that you can use different providers for different services, or prioritize by traffic type.

Connection teaming requires third-party software in addition to the operating system and modem hardware. Teaming is a built-in feature of Intergate from Vicomsoft.

Mainpine multi-port modems:

The RockForce range includes 2, 4 and 8 port boards that are ideal for these applications. They feature V.92 56kbps connectivity, V.44 web compression, modem-on-hold functions and are in a Universal PCI 3.0 Short Board package that will work in any PCI compliant server. We are confident that you will be impressed with these products, which is why we offer a 30 day no-quibble money back guarantee!