Because the Internet offers access to content and users anywhere, each ISP has to secure network connections to all potential senders and recipients of content, or suffer competitively suffer for the lack of global reach. Reciprocal interconnection — whether freely provisioned or provided for a fee — makes it possible for an ISP to access the entire global Internet “cloud” for its subscribers.
The Internet operates almost free of regulation, so Tier-1 ISPs can largely dictate interconnection terms and conditions. ISPs in remote areas (including most developing countries) must meet the entire cost of accessing larger “Tier-1” ISP networks, using expensive international satellite links or submarine cables.
In some cases, where there is no local or regional facility for the exchange of Internet traffic, developing country ISPs must pay for international transit facilities to deliver local traffic. This practice is known as “tromboning” (see Figure 1).
Figure 1: “Tromboning” Developing Country Internet Traffic
A key way to reduce Internet traffic costs for developing country ISPs is through the development of regional Internet Exchange Points (IXPs).
IXPs provide a centralized hub and spoke network typology (see Figure 2). These enable ISPs to hand off traffic directly to other nearby ISPs, and to aggregate long haul access. IXPs offer traffic switching and routing flexibility. By using an IXP, ISPs can individually and collectively reduce their bandwidth and line transmission costs, provide more reliable service with lower latency, and operate more efficiently.
Figure 2: IXP Hub and Spoke Networking
IXPs provide a centralized location for the exchange of traffic, close to both the originators and recipients of traffic and content. Having access to an IXP has a range of benefits for local ISPs, and ISP subscribers. IXPs:
- Reduce the ISP costs, and enable ISPs to manage traffic more efficiently,
- Improve quality of service by reducing the transmission time, number of routers, and distance traffic must travel,
- As a result, add value to an ISP service subscription. This creates new growth and development opportunities,
- Provide a neutral, universally supported “clearing house” for the exchange of traffic, making it possible to keep local traffic local.
RELATED INFORMATION
Supporting IXPs in Developing Countries
Internet Exchange Points in Africa