By contrast all of Zen’s packages, like some other ISPs, have usage allowances which are clearly stated when a customer orders the service. Customers can therefore choose up front the product they require depending on how they intend to use their broadband. Fixed usage allowance packages are easier to design and do not need a FUP (though some ISPs do attach an FUP to their capped products). Zen and other providers will also email customers when they have used 50%, 75%, 90% and 100% of usage.

In addition, Zen’s customers can check their usage at any time via their customer portal or by calling customer services. If necessary, customers can easily purchase more usage to tide them over until the end of the month. Thanks to one month contracts customers can also upgrade to a different product at any time – it doesn't even have to be at the end of the month. Suffice to say that this approach, while less marketable than “unlimited”, is at least more honest.

Traffic Shaping and Management

This usually occurs when demand is too high for an ISP's network capacity - generally at peak times e.g. between 17.00 – 20.00. The ISP restricts or "traffic shapes" the speed of individual customers' Internet connections to accommodate everyone. So whilst a customer is still able to use their broadband the performance will fluctuate, sometimes quite dramatically, resulting in slower speeds and an unreliable connection.

To better explain this we will use a car analogy again:

Imagine the access to the Internet as a motorway and the motorway is managed by an ISP. When everything is running smoothly cars, i.e. broadband users, are travelling down the motorway at a steady 70mph with all 3 lanes open. If the motorway becomes congested at rush hour i.e. lots of users trying to use their broadband at peak times, the ISP will look at what the car is being used for, i.e. as a broadband user this could be email or P2P, and force the car into a slow lane or even prevent the car from going onto the motorway at all. This way the ISP is able to ease the congestion until rush hour is over.

This principal is not all bad and when used properly it should allow the greater majority of customers to experience the Internet’s most useful services (website browsing, email etc.) without suffering excess degradation in service quality, especially during peak times. However it can also be applied far too aggressively, which could lead to some popular services (e.g. BBC iPlayer videos) becoming unusable.