SoftwareTalks

Good backup habits are essential to everyone who uses a computer with important information. It takes just a few accidental clicks of the mouse - or worse, one isolated hardware failure - and valuable data can be lost.

One dilemma for backup users is often where to put their backups. Storing them on your own hard drive is obviously not the best option. Not everyone wants to split their backups into several parts using a CD or DVD burner, and an external hard drive isn’t a standard fixture on many users’ desks.

Offsite backup over a network:

Most backup programs support network backup, and the way to use this is simple. Local Area Networks (LAN) and Wide Area Networks (WAN) usually feature “network drives”, which appear to your computer as an ordinary drive. They often have names like M:, N:, O: and so on. Depending on permissions set up by the people administrating your network, you may be able to write to certain drives but not read from them, or you may not be able to change or delete data once it’s written. These are common situations, but they should not affect the way you back up.

Once you have found a suitable location for your data - your administrator will be able to help you with this - backing up can be as easy and fast as with an external drive. Select the appropriate drive and the data you want to save and that’s it. Even though a network connection is usually not as fast as a local cable, this is just a matter of waiting. Most programs allow you to set a backup timetable, which is a great way to take the effort out of backup. If you leave your computer on at night, then setting an incremental backup every second day at 2am, for example, ensures the safety of your data. A possible disadvantage here is that if your network goes down, you might not be able to get your data back for some time. Laptop users might not always be connected to the network at the scheduled backup time, defeating the purpose entirely.

Offsite backup through FTP:

Another form of offsite backup uses a File Transfer Protocol (FTP) server over the Internet. FTP is traditionally used to move large files online and can reliably transfer any files of any size.

To access data stored on an FTP server, you can use your backup program, a special FTP client or just a regular web browser. While there are two “types” of FTP server, public and private, you will almost certainly be using a private server, which requires a password to access your data. Advantages of this method include that you can view the files stored on the FTP any time you wish using any FTP client, mobile users can back up from anywhere in the world with an Internet connection, and FTP backup can be somewhat cheaper than a specialised remote backup service.

The main disadvantage inherent in this method is data security. The FTP protocol is not secure, and even a private FTP account does not ensure the security of your files; it only protects access to the FTP server. Anyone with access to your username and password has access to your data. Added to this, unless you take steps to protect it, your data will be unencrypted as it travels to the FTP server, and could possibly be intercepted. We recommend that you encrypt your files before sending them.

One option is to store your data in a standard password-protected ZIP archive. This is a quick method that allows you to extract your files on any computer using any ZIP client. There are ZIP programs that provide tighter security by applying stronger encryption algorithms, like AES or Blowfish. This increases the security of your data, but to decrypt your files you may need to use the program that encrypted and backed them up.

To obtain access to a private FTP server, find a good hosting company (try searching with Google) and compare based on price and location - companies with servers based in your country will usually be faster. Beware that your Internet Service Provider (ISP) might charge you for the data you send, so you may wish to make incremental backups over FTP, which only backup what was changed since your last backup.

Specialised offsite backup:

Another form of offsite backup is the use of a special server provided by the company that makes your backup solution. They usually use their own protocols to encrypt and transfer your data, and a special program on their end to store it. You may have some issues using such services if you’re behind a firewall, as some of these services use non-standard Internet Protocol (IP) ports.

Offsite backup services are usually paid for by the month, by the amount of data transferred or both. They can be quite expensive, especially if you wish to back up a lot of data, or use the service over a long period of time. As with FTP servers, you may also be charged by your ISP to send your data.

SoftwareTalks Podcast
(Time 6:46 min; File Size 5.43 Mb)

Almost everyone with an e-mail account has experienced unsolicited commercial e-mail, or ’spam’ - and everyone knows how irritating it can be. Every day we can read about new breakthroughs in anti-spam technology, or another successful prosecution against spam senders located in the United States and Europe.

The running rate for sending around a million spam e-mails now is around US$200. Given that most spam senders are hawking high margin get-rich-quick or impossibly hopeful lose-weight-quick schemes, it takes less than a 0.01% “hit rate” to make a lot of money.

Regardless of how successful spam is for the senders, the fact is that most users dislike it, and want it to stop. The fight against spam, from the user’s point of view, revolves around two solutions: server side and client side filtering. Each has unique advantages and disadvantages.

Server side filtering works from a central server, usually connected to several spam ‘blacklists’ (these lists identify known spam senders) and also analyzes each e-mail based on its individual characteristics. The ability to pool knowledge from analysis of millions of messages can help the accuracy of these systems. The “Report Spam” button on your web mail service is a good example of how spam is eliminated democratically.

Another benefit of server side filtering is traffic economy. When spam messages are caught before they are received, users and service providers do not pay for their delivery. However, server side filtering is not perfect. There is the real threat of “false positives” - genuine e-mails from friends or colleagues identified as spam, and not delivered as a result. Server filters often can’t deliver suspected spam to a special folder that you can look through later. Some servers can also be overzealous in their blacklisting techniques, and block whole Internet Service Providers (ISPs) while a spam outbreak is happening. Every user might find himself unable to send legitimate e-mail and the recipients usually aren’t aware that their e-mail provider, or ISP, is using spam technology that blocks the sender.

Finally, server side filtering can lack the ability to approve certain kinds of e-mails (like newsletters from companies in which you’re interested). You might make a purchase at an online shop and never receive the receipt, lost forever in a spam filter.

Main advantages of server filtering:

- Traffic economy through interception of messages earlier in the delivery chain;
- Spam filtering is based on the analysis of many messages hitting many server users at once, potentially increasing accuracy.

Spam is annoying, but being unable to send an e-mail to a loved one because it’s wrongly identified as spam is much worse. Even though most of our e-mail will pass through a server spam filter somewhere on its journey, server filters suffer from a need to be over-cautious about designating a message as spam, lest this decision be incorrect.

Therein lies the benefit of client side filtering. This technology works in a similar way as described above, except that the work is done by a program on the user’s own PC. Client filters usually depend less on blacklists and more on sophisticated detection methods that search through each e-mail. It’s usually possible to customize the strength of the spam filter, and approve or disapprove of specific senders and domains, be they relatives, friends or industry newsletters. Client filters also deliver spam to special e-mail folders that a user can browse through every so often, to check if any mail has been misidentified.

Main advantages of client filtering:

- Most programs include a folder containing messages thought to be spam, to prevent loss of your messages;
- Wide range of personal settings, such as which senders will always be delivered, which sites may not send you e-mail, and how strong you want your spam filtering to be;
- You are in control of your own spam filtering.

The challenges for all spam filters, no matter what the technology, are huge. For example, on the client side, the better our spam filter gets, the less we tend to check our spam folders, thus increasing the risk of false positives.

SoftwareTalks Podcast
(Time 6:11 min; File Size 4.96 Mb)