For a lot of places in the rural US, the only game in town for WAN connectivity is the local telephone company, know in the business as the ILEC (Incumbent Local Exchange Carrier). Even if you didn’t get your Internet, ATM, or Frame network from that carrier the local loop (The piece between you and the telco central office) always went through the ILEC. For businesses in a rural market that means that many types of service are priced much higher than the same product in another market where there is competition.
My client was a local ISP that was planning an expansion. The conventional wisdom was to build a hub and spoke network using the ILECs frame relay resources (This was before metro ethernet, MPLS, and other services were available). This would carry the ISP’s customers Internet traffic back to their network core were it would then get to the Internet.
This network design originated with the local ILEC sales and engineering team. They were pushing hard to lock up their customer in a multi year deal. They pitched this network design as something that could grow with the client as the market grew and by signing a three year contract that ILEC would wave installation charges. The same type of network was also pitched to the client from the CLEC (Competitive Local Exchange Carrier) where they were colocating their equipment.
The business side of the company just wanted to pit both providers against one another and see which one came out on top in price. I approached the problem from a different route. What’s the best network for the type of traffic we were expecting? That analysis was pretty simple – being an ISP the client’s customers wanted raw Internet access. The only traffic coming from the users to the network core was primarily for email. There was no VoIP traffic, video traffic, or VPN requirements.
The next step was to analyze traffic usage against the proposed network. Once I had those requirements it was very clear that a hub and spoke network didn’t make sense. Why bring data back to the most rural point in the network that had the least amount of redundancy? Why add an extra hop (or 2) for customer traffic to get to the Internet when tier one providers sat right next to the clients equipment in the other CLEC data centers?
My proposed network design was to have each location directly connected to the Internet. This gave the clients userbase the most direct connection to a tier one Internet provider and didn’t bring each region down if one location had a problem. Any traffic that was destined for the clients core came across the Internet. By leveraging the Internet providers and the CLEC I was able to provide four times more bandwidth to each location than I could get guaranteed with the hub and spoke network at a lower cost. By challenging the conventional wisdom we were able to provide a more robust network for the client, that was also less expensive and easier to expand.