 an organiza- tion's core business. Thus, in many organizations the applications remaining in data centers are often customized, complex, and core critical. Moreover, applications centralized in data centers at main and regional headquar- ters require high network availability as more staff members depend on access. Cen- tralization of applications in data centers also requires networks with higher speeds and more capacity to carry ever-increasing amounts of computer data. In summary, streamlined data centers, cloud computing, and virtualization have created more pressure on IT staff members to operate data centers with around-the- clock availability, and networks with ever-increasing capacity. They also require more complex skills on the part of IT personnel. APPENDIX Table 2-1 Protocols and VolP Terms Protocols and Terms for VolP Service Description 802.1pq 802.1pq is used to tag certain Virtual LAN traffic to indicate that it is part of a special group. It might tag voice packets to segregate them for special treatment and monitoring. It also contains bits that identify the packet's priority level. Class of Service provides priority to particular types of traffic. Voice or video can be designated with a higher priority than voicemail. Denial-of-Service attacks occur when hackers attempt to disrupt communications by bombarding endpoints or proxies with packets. Appendix Protocols and Terms for VolP Service Description G.711 G.711 is used to compress voice signals at 64,000 bits per second plus a 6- to 21-kilobit header for VoIP services. It produces good voice quality but uses more network capacity than other compression techniques. This technique requires 60 milliseconds to process and "look ahead" (check the route). G.723.1 G.723.1 is a compression protocol that uses small packets with 6.3Kbps compression. Small packets are more efficient than large ones, in terms of bandwidth use. With the header, total bandwidth is about 16Kbps. G.729 G.729 is a voice compression standard used in VoIP. It com- presses voice