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What an internet exchange is

An internet exchange is a neutral meeting point where networks swap traffic directly. The Internet Society's tracker lists 19 active ones in Canada, two of them in Alberta, and none in southern Alberta outside Calgary.

What an internet exchange is
Transcript

The internet is a network of networks. Your provider runs one. Your bank's host runs another. For your traffic to get from one to the other, those networks have to connect somewhere. An internet exchange is one of the main places they do it.

Picture a neutral room with a switch in it. Networks bring a connection into that room and plug in. Then they trade traffic directly with any other network there that agrees to. That direct trade is called peering. Usually, neither side pays the other.

The other option is transit: paying a bigger network to carry your traffic everywhere. It works. But you pay by capacity, and your traffic goes wherever that network sends it. Every bit that goes over peering instead is transit you didn't pay for, on a shorter path.

The Internet Society lists three main payoffs. Shorter paths, so local traffic stays local. Lower cost, because networks buy less transit. And resilience: if a long-haul line fails, networks at the same exchange can keep swapping traffic.

The Internet Society's tracker lists nineteen active exchanges in Canada. Alberta has two, in Calgary and Edmonton. There's none listed in southern Alberta outside Calgary. None in Lethbridge, Medicine Hat or Regina.

An exchange doesn't make anyone's wire faster, and networks still choose whether to show up. But it's one of the cheapest things a region can add. Calgary's was built by volunteers, on donations. That's why this site marks Medicine Hat as a candidate.

  1. A neutral room with a switch

    The internet is a network of networks. Your provider runs one; your bank’s host runs another. For traffic to get between them, they have to connect somewhere. An internet exchange point (IXP, or “exchange”) is one of the main places they do it.

    Networks bring a connection into a neutral room, plug into a shared switch, and trade traffic directly with any other network there that agrees to. Networks can also link privately, one pair at a time; at an exchange, one connection reaches every network there that agrees to peer. The Internet Society describes an IXP as essential infrastructure where networks come together to connect and exchange traffic. Members are typically internet providers, mobile operators and content networks.

    without an exchange with an exchange 15 links 6 links

    Left: six networks in a ring, every pair joined by its own link, 15 links in all. In general, N networks need N times N minus 1, divided by 2, direct links. Right: the same six networks each run one link to an exchange in the middle, 6 links in all, and can reach each other through it.

    Linking every pair of 6 networks directly takes 15 links. Through an exchange, each connects once: 6 links. Illustration

  2. Peering and transit

    That direct trade is peering. It’s usually settlement-free: neither side pays the other, and each covers its own cost of reaching the room. The other option is transit: paying a bigger network to carry your traffic everywhere. You pay by capacity, and your traffic goes wherever that network sends it.

    Peering doesn’t replace transit; a small network still needs transit to reach everything else. But every bit that goes over peering is transit you didn’t pay for, on a shorter path.

    rest of the internet transit, paid transit, paid in town exchange network A network B network C peering usually unpaid

    Three networks in one town each run a link to a shared exchange in the middle and swap traffic with each other through it: peering, usually unpaid. Networks A and B also each have a separate paid transit link up to the rest of the internet.

    At an exchange, networks in town trade their local traffic directly. Networks still pay for transit to reach the rest of the internet. Illustration

  3. Why it matters here

    According to the Internet Society, exchanges deliver shorter paths with lower delay; lower cost, with less paid transit, which can mean lower prices for their customers; and resilience: if a long-haul link fails, networks at the same exchange can keep swapping traffic.

    The Internet Society’s Pulse tracker lists 19 active exchanges in Canada, most in Toronto, Montreal and Vancouver. Alberta has two: YYCIX in Calgary and YEGIX in Edmonton. None is listed in southern Alberta outside Calgary, or along the Trans-Canada between Calgary and Regina; the nearest listed to the east is in Saskatoon. So traffic between neighbours can detour hundreds of kilometres (see what we measured).

    Calgary not needed Medicine Hat you exchange website network A network B a few km

    Inside Medicine Hat, your network and the website's network both connect to a local exchange. Traffic goes from you to the exchange and straight to the website, a few kilometres, with no trip to Calgary.

    With a local exchange, traffic between two networks in town stays in town. Illustration

How they’re run

Many exchanges are run by non-profits or volunteer groups, and the Internet Society argues they work best when they’re neutral, open and community-built. Calgary’s YYCIX says it was built by volunteers on donations, lists no mandatory recurring membership or port fees, and lists several Calgary data centres where networks can connect.

An exchange doesn’t make anyone’s last-mile wire faster, and networks still choose whether to show up and peer. But it can be one of the cheapest pieces of infrastructure a region adds. That’s why the map marks Medicine Hat as a candidate.

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