rom the rest of the corporate network SO that all devices in the same VLAN can be given a higher priority or level of security. They are programmed as a separate LAN but are physically connected to the same switch as other devices. A group of data devices, usually LANs, that communicate with one another between multiple cities. www.TechnicalPDF.com Table 2-3 Protocols and VoIP Terms Protocols and Terms for VolP Service Description 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. 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 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 is a voice compression standard used in VoIP. It compresses voice signals from 64,000 bits per seconds to 8,000 bits per second. The header brings the total bandwidth to about 18,000 bits per second. H.323 is a family of signaling standards for multimedia transmissions over packet networks adopted by the International Telecommunications Union (ITU). Microsoft Corporation and Intel Corporation adopted the standard in 1996 for sending voice over packet networks. H.323 includes standards for compressing calls and for signaling. It has higher overhead than the newer signaling pro