eing gradually replaced in high-traffic portions of networks by Voice over Internet Protocol (VoIP) technologies, in which voice packets are interspersed with data and video traffic more efficiently, without wasting capacity. Thus, network capacity is not wasted during pauses in voice or data traffic. Both T1 and T3 use TDM and carry voice, video, and data over a single circuit. In North America and Japan, T3 carries 672 conversations over one line at a speed of 45Mbps. T3 is used for large enterprises, call centers, and Internet access. Small and midsize organizations commonly use T1 for Internet access. T1 carries 24 streams over one circuit at 1.54Mbps. Matching multiplexers are required at the sending and receiv- ing ends of each channel. Increasing Network Capabilities via Multiplexing Statistical Multiplexing and Achieving Efficient Utilization via Priority Network Services Unlike TDMs, statistical multiplexers do not guarantee capacity for each device connected to them. Rather, they transmit voice, data, and images on a first-come, first-served basis, as long as there is capacity. Ethernet is an example of statistical multiplexing. It can be used in a Wide Area Network (WAN) to connect customers to the Internet. It is also the most common method of accessing LANs within buildings. On Ethernet LANs, if more than one device attempts to access the LAN simultane- ously, there is a collision and the devices try again later. Ethernet used for LAN access is located in each network-connected device, such as a printer, computer, or security monitor. Statistical multiplexers support more devices than TDMs because they don't need to save capacity when a device is not active. Carriers sell WAN Internet access via Gigabit Ethernet offerings, supporting a range of speeds from 10Mbps to 10Gbps. If there is a surge in traffic, such as during peak times, the carrier can temporarily slow down traffic. However, because Gigabit Ethernet's statistical multiplexing has the capability to prioritize traffic, customers who contrac