, depending on congestion or network failures. MPLS Implementation www.TechnicalPDF.com When customers sign up for MPLS service, they give their provider a list of the IP addresses associated with each site that they want included in their MPLS service. Each IP address identifies a specific location on a network. The carrier uses this list to define a closed group of sites that are allowed to communicate with one another over the MPLS network. The list can be amended by notifying carriers of IP addresses to be added or deleted. In addition to an IP address, each location connected to the MPLS network requires an access line from the customer to the carrier's network. However, a single link from each location can transmit messages to all sites. Each location does not need a separate physical connection to every other site on the MPLS network. The MPLS service is referred to as an any-to-any network. MPLS is a Layer 3 protocol that switches traffic between IP addresses rather than Media Access Control (MAC) addresses. MAC addresses are assigned to individual computers and other devices on a network. With MAC addressing the message is received at the customer end, and onsite equipment sends the MPLS content to individual devices. By contrast, IP addresses are assigned to the network or to the Virtual LAN (VLAN). Managing fewer addresses makes routing by using MPLS with its IP addressing less complex to manage. It also enables networks to scale to larger sizes. MPLS is an optional feature in routers. MPLS for Multinational Locations Internationally, most large providers have a presence in Europe, the United States, the Middle East, and parts of www.TechnicalPDF.com Asia. However, they have less presence in fewer Latin American cities, and the lowest presence in Africa. The term presence means that they have a switch in a local provider's Point of Presence (POP). A POP is the physical building in which a telephone company's switch (central office) is located. The POP is connected to the Internet as well as to other ce