To understand WAN technologies, you need to understand the different WAN terms and connection types that can be used to connect your networks together. This section will discuss the different WAN terms and connection types typically used by service providers.
Defining WAN Terms
Before you order a WAN service type, it is important to understand the terms that the service providers use. Customer premises equipment (CPE) Equipment that is owned and located at the subscriber’s premises.
Demarcation (demarc) : The last responsibility of the service provider, usually an RJ-45 jack located close to the CPE. The CPE at this point would be a CSU/DSU or ISDN interface that plugs into the demarc.
Local loop : Connects the demarc to the closest switching office, called a central office.
Central office (CO) : Connects the customers to the provider’s switching network. A CO is sometimes referred to as a point of presence (POP).
Toll network : Trunk lines inside a WAN provider’s network. It is a collection of switches and facilities. It is important to familiarize yourself with these terms, as they are crucial to understanding WAN technologies.
