## Appendix A: Glossary of Terms

802.1D 802.1Q | 802.1Q defines a layer 2 frame structure that supports VLAN identification and a QoS mechanism usually referred to as 802.1D.
ARP | Address Resolution Protocol, used, for example, to verify that the IP address provided by the DHCP server is not in use by another IP telephone.
CELP | Code-excited linear-predictive. Voice compression requiring only 16 kbps of bandwidth.
CLAN | Control LAN, type of Gatekeeper circuit pack.
CNA | Converged Network Analyzer, an Avaya product to test and analyze network performance.
DHCP | Dynamic Host Configuration Protocol, an IETF protocol used to automate IP address allocation and management.
DiffServ | Differentiated Services, an IP-based QoS mechanism.
DNS | Domain Name System, an IETF standard for ASCII strings to represent IP addresses. The Domain Name System (DNS) is a distributed Internet directory service. DNS is used mostly to translate between domain names and IP addresses. Avaya 9600 Series IP Telephones can use DNS to resolve names into IP addresses. In DHCP, TFTP, and HTTP files, DNS names can be used wherever IP addresses were available as long as a valid DNS server is identified first.
Gatekeeper | H.323 application that performs essential control, administrative, and managerial functions in the media server. Sometimes called CLAN in Avaya documents.
H.323 | A TCP/IP-based protocol for VoIP signaling.
HTTP | Hypertext Transfer Protocol, used to request and transmit pages on the World Wide Web.
HTTPS | A secure version of HTTP.
IETF | Internet Engineering Task Force, the organization that produces standards for communications on the internet.
LAN | Local Area Network.
MAC | Media Access Control, ID of an endpoint.
Media Channel Encryption | Encryption of the audio information exchanged between the IP telephone and the call server or far end telephone.
NAPT | Network Address Port Translation.
NAT | Network Address Translation.
OPS | Off-PBX Station.
PHP | Hypertext Preprocessor, software used to assist in the format and display of Web pages.
PSTN | Public Switched Telephone Network, the network used for traditional telephony.
QoS | Quality of Service, used to refer to several mechanisms intended to improve audio quality over packet-based networks.
RSVP | Resource ReSerVation Protocol, used by hosts to request resource reservations throughout a network.
RTCP | RTP Control Protocol, monitors quality of the RTP services and can provide real-time information to users of an RTP service.
RTP | Real-time Transport Protocol. Provides end-to-end services for real-time data such as voice over IP.
SDP | Session Description Protocol. A well-defined format for conveying sufficient information to discover and participate in a multimedia session.
Signaling Channel Encryption | Encryption of the signaling protocol exchanged between the IP telephone and the call server. Signaling channel encryption provides additional security to the security provided by media channel encryption.
SIP | Session Initiation Protocol. An alternative to H.323 for VoIP signaling. This protocol is not applicable to 9600 Series IP Telephones.
SNTP | Simple Network Time Protocol. An adaptation of the Network Time Protocol used to synchronize computer clocks in the internet.
TCP/IP | Transmission Control Protocol/Internet Protocol, a network-layer protocol used on LANs and internets.
TFTP | Trivial File Transfer Protocol, used to provide downloading of upgrade scripts and application files to certain IP telephones.
TLS | Transport Layer Security, an enhancement of Secure Sockets Layer (SSL). TLS is compatible with SSL 3.0 and allows for privacy and data integrity between two communicating applications.
UDP | User Datagram Protocol, a connectionless transport-layer protocol.
Unnamed Registration | Registration with Avaya Communication Manager by an IP telephone with no extension. Allows limited outgoing calling.
VLAN | Virtual LAN.
VoIP | Voice over IP, a class of technology for sending audio data and signaling over LANs.
WML | Wireless Markup Language, used by the 9600 Series IP Telephone Web Browser to communicate with WML servers.