A MAE (pronounced MAY), originally an abbreviation for Metropolitan Area Exchange and now a service mark of MCI WorldCom, is a major center in the United States for interconnecting traffic between Internet service providers (ISPs). There are three major MAEs in the United States: MAE-East in the Washington, D.C. area; MAE-West in the San Jose, California area; and MAE-Central in Dallas, Texas. These three points along with several interconnection points previously identified by the National Science Foundation as network access points (NAPs) form what is sometimes considered the national commercial Internet backbone. In addition to MAE-East, MAE-West, and MAE-Central, there are two central MAEs for frame encapsulation (FE) service -- in Chicago and New York. The MAEs and their services, originally developed by MFS Communications, are now owned and operated by MCI WorldCom.
A MAE can be viewed as a giant local area network (LAN) switch. In fact, the three major MAEs use a Fiber Distributed-Data Interface (FDDI) switch. The only ISP device that can interconnect to a MAE switch is a router or a computer host acting as a router. The ISPs work out their own peering agreements and manage their own routing tables. Routers at the three major MAEs need very large routing tables. Cisco's 7xxx series routers are examples of such routers.
The MAEs offer colocation space for ISP equipment on their premises.