Network Platforms is a specialist Internet and networking company. MD Bradley Love gives some guidelines for users wanting to get the best value-for-money from their ISPs.
There`s a price war being fought on the broadband front, with providers vying to offer the lowest prices on ADSL services. The challenge for users is to discern whether what they are paying for is worth the drop in price – or if the marketing hype is just a smokescreen hiding a second-rate service.
Anyone thinking of taking up one of the new ADSL products must ask ISPs some key questions if they are to discover what is really on offer.
The first ISP to start the price war was Afrihost. This sparked many other ISPs to jump on board or lose customers. While the price war is fantastic for South African consumers, many smaller ISPs will be feeling the crunch in competing with current prices.
There are three ways that South African ISPs deliver ADSL to the end-user. These are:
1. Install an IP Connect (IPC) supplied by Telkom.
2. Install their own RADIUS servers to connect to the Telkom IPC.
3. Use the Telkom RADIUS servers on the Telkom IPC.
ISPs leverage these mechanisms to achieve their specific pricing models. The larger Internet service providers (ISPs) install their own IPC, which connects directly to Telkom`s backbone. This is the most efficient way of obtaining bandwidth because the ISPs obtain their connectivity straight from Telkom`s edge switch routers.
The advantage of this is that any traffic on the IPC is not billed for over and above the IPC cost, so ISPs using this mechanism can offer their clients better prices. For example, if an ISP has a client with multiple branches using a virtual private network (VPN), the traffic between the branches is not billed for because it travels on the IPC.
However, the ISP must over-subscribe the number of users on its IPC for it to be profitable – unless it charges premium rates for an uncongested IPC. So the most important question that consumers must ask of their ISPs is: `What is your contention ratio?`
A contention ratio reflects the maximum number of users on the network. The more users there are, the less bandwidth is available to each. Most ISPs offer anything from 20:1 to 50:1. The lower the contention ratio, the better the bandwidth the user will access.
It`s like the amount of traffic on a highway – the more vehicles there are, the slower the traffic moves, and vice versa. Hence Internet users should seek ISPs that have the lowest contention ratios.
The price of international bandwidth has dropped significantly with the advent of new intercontinental connections. Previously, all international network traffic flowed through Telkom`s SAT3 link. The new Seacom fibre-optic link has broken Telkom`s monopoly on international connectivity and many ISPs are opting to route their international traffic through this link at a cheaper rate.
ISPs use some other cunning infrastructure tweaks to reduce costs. One way of doing this is to install proxy devices that cache commonly accessed data. For example, if one user downloads a Microsoft update, this update will be saved on the local proxy server so that it is only downloaded once from the overseas source. The next client to download that same file will be downloading it from the local proxy rather than from Microsoft`s US-based server.
Still, the problem remains that if the ADSL network is over-subscribed – in other words there are just too many subscribers to maintain efficiency at peak use periods – then users will experience an inconsistent service. Sometimes they will have good download speeds, but in peak traffic periods, Internet connectivity will slow to a crawl – just like rush hour traffic on a city highway.
But for the ISP, more traffic means more money – so the more users they have, the cheaper the prices they can charge their clients. Users must evaluate their bandwidth speed requirements before just jumping to the cheapest provider, and the contention ratio is the means to measure the service offering.
The second means by which ISPs provide connectivity is where they have their own RADIUS (Remote Authentication Dial In User Service) servers that connect to the Telkom IPC. RADIUS servers control and measure user names and usage. Telkom`s IPC contention ratio is 20:1, which is a standard that many international ISPs have settled on. This ratio provides a good balance of traffic flow per user and allows the network to provide Internet connectivity at a reasonably consistent rate.
For the ISP, this method is not as flexible as having its own IPC – but it does allow ISPs to create any size account and it enables a fair amount of troubleshooting capacity. The price of this service is set by Telkom Wholesale, which has just reduced the cost this month. However, Telkom also sets the specifications for RADIUS servers, so the functionality is limited in comparison to an IPC.
The third method of ISP connectivity is to utilise Telkom`s own RADIUS servers on the Telkom IPC. Because this utilises Telkom`s IPC the contention ratio is also 20:1 – but the disadvantage is that the ISP is restricted to Telkom`s predefined account sizes (eg, 1GB, 2GB, 5GB etc). This means that custom accounts can`t be created unless they are defined on Telkom`s SAIX RADIUS servers. The ISP must also rely on SAIX for information on troubleshooting issues, and these factors mean that users will get a more limited service offering.
Clients must look at the ISP`s terms of use for the broadband product. These specify certain limitations on broadband supply and this may result in the service being reduced or certain protocols shaped even terminated if the client exceeds these limitations.
The bottom line is that if you want good connectivity, get in-depth information about an ISP before buying their product. That way you`ll ensure you get the right service to suit your needs.
