. But, many experts believe that the capacity on these circuits will not be adequate for future requirements. This adds pressure to increase capacity to more closely match consumer and business consumption of data and video services. A number of factors are increasing the demand for bandwidth. For enterprise and commercial customers, the trend toward centralizing applications within enterprise and cloud data centers is a key cause. As more remote offices and telecommuters access centralized files, high-speed links are becoming increasingly critical at remote offices, cloud-based data centers, and the data centers that need bandwidth to handle these requests. The high cost of travel, lost productivity, and improvements in video conferencing are additional factors contributing to increased demands on bandwidth. Skype video conferencing was initially used by consumers and then adopted by enterprises. Its ease of use and worldwide adoption meant anyone with broadband Internet access could spontaneously initiate video conferencing at the office, from home, and while traveling. Large enterprises that use Skype often also often use the higher-quality video con- ferencing that consumes large amounts of bandwidth on LANs and requires priority service. For this reason, many videoconferences now take place on quality-controlled, private IP networks offered by carriers. These networks use Multi-Protocol Label Switching (MPLS) and are operated separately from the Internet. Customers access MPLS networks via high-speed links, such as Gigabit Ethernet (GigE), T1, and T3. T1 and T3 services are examples of older Time-Division Multiplexing (TDM) technologies. These services are limited to speeds of 1.54Mbps on T1 and 44Mbps on T3 links. TDM technologies save fixed capacity for each message and voice con- versation. Although this guarantees voice quality, it is inefficient because capacity is wasted during pauses in transmissions. (See the section "T1 and the Inefficiencies of Time-Division Multiplexing," later in this chapter, fo