Munich  - In the best-case scenario, people just have to deal with their internet routers twice - when buying and when installing them.

But routers, which connect computers to the wider internet, sending messages and downloading data packages, come in all shapes and sizes nowadays, so check the selection before making a purchase.

There are two important considerations when purchasing a router. Is it pre-packed with a modem? And is it WLAN-capable or able to access the internet wirelessly? Price differences between WLAN and non-WLAN capable routers are minimal, says Johannes Endres of the Hanover-based c't computer magazine.

When choosing a WLAN, remember that a wireless connection will not be quite as fast as a cabled one. Manufacturer's data on transfer rates are estimated and generally not achievable.

For a really good WLAN connection, Stefan Rojacher, a spokesman for the Munich-based router manufacturer Netgear recommends a dual- band router with either 2.4 and 5 gigahertz.

"The 5 gigahertz frequency is less common and not as prone to disruption."

Other routers offer different features such as a USB connection or an integrated hard drive.

"Those are all right for transferring data," said Endres, but cautioned users against expecting such devices to transfer information as fast as a proper server. Many routers also come with a telephone connection, which is practical for anyone who wants to telephone via the internet.

When shopping, Enders advises looking for devices with particularly basic graphics displays. It's also important to make sure it displays information in your native language as even the best router is useless, if you can't understand it.

WLAN routers are practical because they function without cables. But caution is advisable as most routers are made to meet these security requirements.

Home users should make sure to activate security, either WPA or WPA2, and to set up a good password ideally one containing plenty of characters and which is hard to guess, Enders said.

The router also needs its own password in case someone tries to access it in a bid to reconfigure the software.

Lastly, Endres recommends switching off remote access software. "It's designed to let technicians access the system from outside. But it creates a security risk and should really be turned off as soon as the router is operational."

Once the router is up and running, any WLAN service should initially be shut down and the computer connected to the router via a cable, says Matthias Gaertner of the German Federal Office for Information Security.

"A good password is very important, but you should also change the router's name from the provided one."

Many users also set their router so that it's invisible to strange computers, but this does not mean additional security.

"Besides, it can be a nuisance for people who have to use the network."

Routers usually provide some protection from attacks as they form a firewall, says Endres. However, a user should still protect a computer from viruses and Trojans with an anti-virus program.

If the WLAN signal cannot be encrypted, then it's better not to surf wirelessly at all, says Gaertner.

"If in doubt, use a cable as backup when configuring the WLAN." (dpa)