> Shouldn't this be in favour of the ISP? If the traffic isn't balanced, then doesn't the peer that's sending more (e.g. YouTube, Netflix) usually pay? No, the

> Shouldn't this be in favour of the ISP? If the traffic isn't balanced, then doesn't the peer that's sending more (e.g. YouTube, Netflix) usually pay? No, these providers end up peering or placing CDN edge nodes on the provider network and essentially don't pay for their transit. They get this arrangement because it reduces the distance that the high-tier ISPs have to move their traffic. The basic problem is this: ISPs enter peering arrangements with each other to avoid the bureaucracy of both paying each other to access the other's customers. As a consumer ISP, you only have end users, not service providers (or at least you have many more end users than service providers). So, your customers want to access to other networks. No other networks want to access your customers. This means that you don't have the negotiating position to set up peering agreements (because only your own customers would be affected by not having one). In general, peering agreements are becoming very strained over the last five plus years because the underlying assumption of traffic symmetry is virtually never true for consumers now. In practice most of the high-tier ISPs business is providing consumers with access to Netflix. Netflix doesn't care about getting access to anyone else. So no one likes to peer with consumer ISPs, even the big ones, because there's nothing in it for them. This has produced some very high profile disputes with major consumer ISPs dropping peering with tier-1 providers. > Looking online, it looks like the prices are $15 to $30 per IP address, depending on the size of the block. So I guess this cost swallows the first month of revenue from each new customer. Yes, but you don't buy addresses onesy-twosy. If you're going to buy your own block you're probably going to want at least a /24 (255 addresses). That runs upwards of $5k. Most small ISPs start up with very little capital and that's out of reach. Plus you'll need to participate in BGP which is out of the technical expertise of most of the people I know running WISPs, although sometimes you can pay your transit provider to handle BGP for you.