Guaranteed or Shared Bandwidth: Choosing the Right Channel


Web projects rely heavily on their Internet connection; no online service today can function normally without good bandwidth. Overlooking the speed and quality of your Internet connection can lead to serious consequences: loss of users, damaged reputation, lack of revenue, etc.

As you know, there are two main kinds of bandwidth: guaranteed and non-guaranteed (a.k.a. shared). Let’s take a closer look at each of these.

Shared Bandwidth

When bandwidth is shared, resources are dynamically redistributed among its users. Because of this, there is no consistent connection speed.

How is a connection with shared bandwidth set up? An ISP has a channel with limited bandwidth that connects to an uplink. The channel’s resources are shared by its users. In this case, there are always more users than the channel’s bandwidth permits. This is called oversubscribing. It’s not unheard of to find a 200 Mbps bandwidth channel (which is fairly average) in use by hundreds, if not over a thousand clients. How is this possible?

These clients are never all using the channel at the same time, so the channel is never at max capacity. There is always a reserve, which is constantly redistributed among the active users. The obvious advantage here is that users get an Internet connection at low cost.

However, since resources are continuously being redistributed, there is no way to guarantee a stable connection speed. Speeds can drop critically low during peak loads.

Shared bandwidth costs are almost always directly related to the amount of traffic actually used. This is what attracts many user who think, “Why pay extra for guaranteed bandwidth if I don’t use any extra traffic?” In theory, this is a fairly convincing argument, but the situation is completely different in practice. People who choose shared bandwidth unavoidably encounter a number of drawbacks.

Firstly, connection speeds are almost always lower than the service provider advertises. Sure, exact numbers are shown in the contract, but those are only maximum speeds: since the channel’s resources are shared among countless “neighbors”, these speeds can’t usually be achieved (in legal documents, this is often described with streamlined formulas, which not every user catches the first time around). Some companies practically warn users flat out that servers connected to the Internet with shared bandwidth shouldn’t be used for storing or distributing “heavy” content.

Secondly, there is always the risk of channel degradation: since the volume of traffic is constantly fluctuating, speeds can drop so critically low during extreme loads that not even a small amount of data can be transferred across the channel.

Thirdly, shared bandwidth usually requires you pay according to pricing plans that are awkward and not truly cost-effective. Prices may seem low and like a good deal at first, but again, this is entirely different in practice.

The principle behind paying per use is that you pay for increases in traffic. Here, unexpected peaks in network activity can have expensive consequences.

Some low-cost hosts can be a bit tricky. They may advertise that they don’t charge clients for using shared bandwidth unless they exceed a particular amount of traffic, but as they say, only the mousetrap has free cheese.

When the allotted amount of traffic has been exceeded, connection speeds are immediately reduced. You see this with many hosting providers: as soon as the amount of outgoing traffic surpasses the pre-established limit, speeds may drop from the advertised 200 Mbps to 10 Mbps. The client then has to pay extra to remove this cap. This limit is more or less tolerable, but some companies put limits not only on outgoing traffic, but on incoming traffic too. Thus, these prices look good on paper, but planning your expenses with shared bandwidth can prove challenging.

Guaranteed Bandwidth

Guaranteed bandwidth means it has a guaranteed (i.e. constant) data transfer rate. What guarantees it?

Let’s say two points are connected by a physical communications channel. With special equipment, we can build on this and get an electric communications channel with a defined bandwidth. What we’re left with is an information channel with a somewhat limited data rate. When one physical channel is used by several users, the channel is divided into sub-channels. Each of these sub-channels has a guaranteed bandwidth. In some cases, the speed of a sub-channel can even be increased if resources are available from other channels.

A guaranteed channel is almost always symmetrical. This means incoming and outgoing traffic does not slow down when large amounts of data are transferred in either direction.

Guaranteed channels have the following advantages:

1. Stability. The Internet connection speed is consistent, even at peak loads.

2. Guaranteed quality. When setting up an Internet connection, the user and service provider sign a Service Level Agreement (SLA), which indicates the connection speed that should always be provided. The SLA also clearly states the amount of time it takes to restore Internet access in the event of failure.

3. Fixed pricing. The cost for using guaranteed bandwidth is fixed. This makes it significantly easier to budget a project. To an inexperienced user, it may seem like you are overpaying by not using the channel’s maximum capacity. This is not a strong argument: from the increase in traffic and capacity, it’s clear that fixed pricing is much more cost-effective than a pay-per-use plan, which often contains hidden fees and conditions (see above).

Which to Choose?

Based on the above facts and arguments, we can come to just one conclusion: shared bandwidth is in no way adequate for a modern, developing web project. Most ISPs that offer shared bandwidth don’t present their pricing policy in an honest light: the advertised speed is almost never actually achieved and information about added fees and traffic limits is rarely available in plain language.

Since “heavy” media makes up the bulk of global Internet traffic, shared bandwidth is a short-sighted decision.

Guaranteed bandwidth is distinguished by its stability and simple and transparent pricing policy: your connection speed will be guaranteed and at a fixed price. As projects develop and expand, guaranteed bandwidth will more than pay for itself.