When you send an email from New York to Japan, that email,is sent from your home to the local exchange point over the access network. Once it is in the local exchange it is then sent to aggregating points in different cities and counties over the regional network. Then it is aggregated and transported over the long-haul network so that it reaches the launching point at the country shoreline where it is then sent over the ocean network to Japan. Once there, the email is sent back over the long-haul or regional network to the local exchange and then on to the individual receiving the email. This occurs using mostly fiber optics so the speeds at which all this takes is at the speed of light which is approximately 127,000 miler per second.
To understand how to interface with the local exchange you must first understand the different networks that comprise it. The first network being the access network. The access network is the network that connects the individual user or business with the telecommunications system. This is made up of a series of fiber-optic and copper cabling and passive and active equipment that connects you to the local exchange. The central office at the local exhange contains the switching equipment to direct your telephone, data , video, etc. to where it needs to go. The access network is very important to the local exchange since its the part that reaches the end user, who is you, and connects them. The metro network, sometimes called a MAN (metro area network), is where the information is collected from the local exchange of the service provider as well as other service providers and and then sent on to the regional and long-haul networks. The regional network, sometimes called a WAN (wide area network) is basically just a larger version of the MAN or metro network.
This is usually the last point before the information is sent to the core network. The core network or long-haul networkis responsible for sending the information collected from the metro and regional networks over very long distances to the metro and regional networks of a different part of the geography, for example sending the email from New York to Japan. Because of the great distances this information must travel on the long-haul network these networks will be set up so that there is always more than one route to get to the destination point. Ocean networks are the most complicated and technically advanced networks that connect different continents to one another. These networks are also the most expensive to install since optical fiber cables for these networks have to be installed on or under the ocean floor.