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3Com® IP Acronyms and Glossary

TECHNOLOGY GUIDE

ACRONYMS AA DiffServ ITU Auto-Attendant Differentiated Services International Union (www.itu.int) ACD DNIS Automatic Call Distribution Dialed Number Identification IVR Service Interactive Voice Response ADSL Asymmetric Digital Subscriber DSS/BLF Kbps or Kb/s Line Direct Station Selection/Busy Kilobits per second Lamp Field AES KTS Advanced Encryption Standard DTMF Key System Dual-Tone MultiFrequency ANI LAN Automatic Number Identification E911 Enhanced 911 ANSI LCR American National Standards E&M Least Cost Routing Institute (www.ansi.org) Earth and Magnet (signaling) Mbps or Mb/s API ETSI Megabits per second Application Programming Interface European Standards Institute (www.etsi.org). MIB ATM Management Asynchronous Transfer Mode FXO Database B2BUA Foreign eXchange Office Back-to-Back User Agent FXS Modulator/Demodulator BRI Foreign eXchange Subscriber Basic Rate ISDN MOS HTTP Mean Opinion Score CAS Hypertext Transfer Protocol Complement Attendant Software MPLS IEEE Multi-Protocol Label Switching CDR Institute of Electrical and Call Detail Reporting Electronic Engineering NAT Network Address Translations CLI/CLID (www.ieee.org) Calling Line Identification NBX® IETF Network Branch eXchange CO Engineering Task Force Central Office (www.ietf.org) NCP Network Call CoS IM Class of Service Instant Messaging NOS Network Operating System CRM IMAP Customer Relationship Internet Access Protocol NPA Management Numbering Plan Area IP CTI PABX Telephony Integration Private Area Branch Exchange IPS DCA Intrusion Prevention System PAN Desktop Call Assistant Personal Area Network IPsec DES IP Security PBX Data Encryption Standard Private Branch Exchange ISDN DHCP Integrated Services Digital PCI Dynamic Host Configuration Network Peripheral Component Protocol Interconnect DID/DDI ISO Direct Inward Dialing/Direct International Organization of POP3 Post Office Protocol 3 Dialing Inward Standardization (www.iso.org)

1 3COM® IP TELEPHONY ACRONYMS AND GLOSSARY

ACRONYMS—continued

POTS SMTP VCX™ Plain Old Telephone Service Simple Transfer Protocol Voice Core eXchange

PRI SNMP VLAN Primary Rate Interface Simple Network Management Virtual LAN Protocol PSTN VM/MS Public Switched Telephone SRTP /Messaging System Network Secure Real-Time Transport Protocol VoIP QoS Voice over Internet Protocol TAPI Telephony Application VPIM RSVP Voice Profile for Internet Mail Reservation Protocol Programming Interface VTL TCP/IP RTP Virtual Tie Line Real-Time Protocol Transmission Control Protocol/ Internet Protocol W3C RTSP World Wide Web Consortium Real-Time Streaming Protocol TLS (www.w3.org) Transport Layer Security SDP WAN Session Description Protocol TSAPI Telephony Application SIP Programming Interface Wi-Fi Session Initiation Protocol Fidelity UCD SIMPLE Uniform Call Distribution WLAN Wireless LAN SIP Instant Messaging and UDP User Datagram Protocol Presence Leveraging Extensions XML Extensible Markup Language UMTS SMDI Universal Mobile Simplified Message Desk Interface Telecommunications System SMDR (www.umts-forum.org) Station Message Detail Recording

2 3COM® IP TELEPHONY ACRONYMS AND GLOSSARY

TERMS 3—C 3G provide dialing instructions for Bridged Appearance Third-generation digital cellular reaching certain users, departments Allows joint management of an mobile standard for delivering or a live attendant. extension by enabling specified high-speed data to mobile devices; phones to simultaneously share a will eventually deliver packet- Auto-Discovery line appearance; typically used in A feature that “discovers” a new based mobile as an executive/admin environment telephone or other device on the IP Multimedia Subsystem (IMS) where the admin can see, answer network and provides it with architectures are implemented. and manage calls made to multiple service without specific directions . 802.11a/b/g from a system administrator. Standards for wireless networking Buffer using unlicensed spectrum Automatic Call Distribution (ACD) Area in a device for temporary A call management system that for Wi-Fi communications. storage of data in transit; can routes calls to queues so they can accommodate differences in pro- be answered by appropriately Abbreviated Dialing cessing speeds to facilitate a clear Also known as speed dialing, skilled agents. The ACD can transmission between devices by allows a list of frequently called manage individual and groups of storing data blocks until they are numbers to be stored in system ACD agents, as well as recorded ready to be processed by a slower memory and accessed via a two- announcements presented to device. or three-digit code. callers; the software also can provide database reports on both Busy Override Account Codes calls and agents. Allows users to override a busy Allows a phone user to enter an signal to break into an existing account code that will appear in a Automatic Hold Recall conversation; most systems, but record of calls made or received; Allows calls to be placed on hold not all, offer this feature with a codes can be forced or unforced; and recalls the called party if warning tone that is given to all optionally, they can be verified there is no response to the call parties of a current conversation. against an allowed code list within a specified period of time. defined by an administrator. Call Accounting System Auto-Redial Usually an external application to A modem, or telephone fea- Ad-hoc Conference a telephony system which merges Conference bridge facility where ture that redials a busy number call detail records with call costs, parties can call a number at any- a fixed number of times before facilitating client and/or depart- time and be placed in conference, disconnecting. mental billing and helping verify sharing a pool of conference ports bills. with no guarantee of availability; Auto-Relocation A feature that allows a telephone unlike scheduled conferences with to keep its extension number and Call Coverage pre-booked resources; also known Pre-configured routing for calls personal and systems settings at meet-me conferences. which are unanswered by a called when it is connected to a different extension or port on the network. Attendant Console rules; frequently configured to A standard telephony device that voice mail. shows the status of each extension Back-to-Back User Agent (B2BUA) A device that follows the rules of in a telephone system, allowing a the Session Initiation Protocol (SIP) Call Detail Record (CDR) receptionist to connect incoming Saved call information relating to —standard RFC3261—for a user calls to the requested destination. number dialed, duration, etc.. agent (client), but relays signaling Authorization Codes (CoS Override) to other clients or proxies; enables Caller Identification Allows phone users to temporarily comprehensive features to be › CLID (Calling Line IDentification): override the configured Class of delivered to SIP clients without indicator on the phone receiving Service (CoS) on a phone and the constraints of being a SIP proxy. a call the caller’s name or phone access additional services by number; Caller ID is a service using their authorization code; Basic Rate ISDN (BRI) that a local phone company or Two-channel ISDN service usable usually enabled by entering a service provider can offer that for voice or data (2 x 64 Kbps). user’s extension number and PIN. displays a CLID. Bit › ANI (Automatic Number Identi- Auto-Attendant (AA) Unit of information within binary An application that answers fication): indicator of caller data data represented by one or zero. incoming calls with a menu of displayed on the phone receiv- options; a recorded greeting may Bluetooth ing the call. When the call is be followed by a transfer to a live Wireless standard for short-range, routed to a PBX via an ISDN attendant or station, or it may device-to-device communications trunk from the public telephone (www.bluetooth.com). network, the caller’s phone

3 3COM® IP TELEPHONY ACRONYMS AND GLOSSARY

C—E

number (ANI) is automatically Camp-On Busy assistance, allowing easier and processed for future reference. Allows a caller to request an auto- faster access to called parties. › DNIS (Dialed Number Identifi- matic callback from a busy exten- sion when that user is free. Directory Service (on LCD phones) cation Service): indicator of Look-up functionality that allows data about the number called Central Office (CO) users to enter a name or set of that is displayed on the caller’s Term used by service providers characters on a phone’s keypad to phone. When the call is routed for the site that houses the display a needed phone number. to it, the PBX processes the switching equipment for their DNIS for display. public telephony services. Distinctive Ringing A system configuration that iden- Call Forward tifies callers or their locations by Enables users to arrange for calls A allocation method unique ringing patterns; may to be sent to another phone in for using a fixed portion of the also be combined with Personal defined situations; can be imple- network and creating end-to-end Ringing. mented for: connections that are open during › busy calls only the full duration of the communi- Do Not Disturb A feature that prohibits calls from cations session. › no-answer calls terminating at a particular phone. › all calls Class of Service (CoS) User profiles defined by a system Do Not Disturb with Override › fixed calls: forwards to an A capability that allows author- administrator to restrict or allow assigned location (generally ized users to override the Do Not access to specific features and customizable), such as a manager Disturb feature and have their calling privileges and services. to an admin calls ring the phone that is in Do › override/return calls: allows Not Disturb mode. a call to override a forwarded Coder/decoder for handling audio signals over a data network; e.g., Door Phone call and return it to the call An intercom box or a combination G.711 and G.729. forwarder’s phone intercom box/electronic door lock › off premise calls: allows calls to Complement Attendant Software that can be installed on an outside be forwarded off-site (CAS) door and directly connected to a A desktop call control application specific phone or to the system. Call Park with advanced features to improve Allows users to transfer calls to call handling for receptionists. Dual-Tone MultiFrequency (DTMF) Parking or Orbit zones where the Signaling calls remain on hold until picked Computer Telephony Integration A tone-based signaling system up at the same station or at another (CTI) that can be used for initial dialing The integration of appli- location. or leveraged to communicate to a cations with voice systems through call processing application after Call Park (with Recall) specialized software applications the initial call is established. An automatic function of some (middleware); applications include Interactive voice response (IVR) systems that recalls either the contact center software which systems may prompt the user to original phone or the attendant will manage call routing based on enter information via the dial pad to ensure that the caller is not business rules and enable viewing that will be sent via DTMF tones forgotten when a call is placed in caller information on a PC when a that correspond to the key(s) that a Park location for an extended call is received. were pressed. period of time. Conference Dynamic Host Configuration Call Pickup (Directed, Group) Pre-scheduled or ad-hoc calls Protocol (DHCP) Enables any user or a group of with multiple parties. Software that dynamically assigns users to pick up a call ringing at IP addresses to network devices an unattended station; one group Desktop Call Assistant (DCA) such as workstations, IP phones On-screen dialing and contact member can dial an access code to and gateways, allowing network management software. pick up a call ringing at an unat- devices to be easily moved from tended member’s station. Direct Group Calling one subnet to another without Allows users to call a group of administrative attention. Call Waiting stations such as a sales department An indication to a user who is by dialing a group code number. E1 engaged on one call that another European digital transmission for- is trying to connect; a recorded Direct Inward Dial (DID)/Direct mat that carries signals at 2 Mbps message can be used to let the Dialing Inwards (DDI) (32 channels at 64 Kbps, with 2 caller know that the called user Connects calls from the public channels reserved for signaling is being alerted. network directly to the dialed and controlling). extension without attendant

4 3COM® IP TELEPHONY ACRONYMS AND GLOSSARY

E—I E&M (Earth & Magnet) Signaling Foreign Exchange Station (FXS) users, any of whom can answer A legacy signaling system used An interface that connects directly the calls. Users can usually log over two- and four-wire analog to a standard analog phone, fax in and log out of hunts groups. connections. machine or similar device, sup- Administrators can determine plying ringing voltage, behavior with a variety of hunt Enhanced 911 (E911) and similar signals to the end- group types, including: An emergency system, based point device. on database information, that › linear: starts with the same transmits a caller’s phone Frame Relay extension in the group each A high-speed number and location directly time and continues ringing all protocol in which unprocessed to emergency responders. the phones in the group until a packets are relayed from a user answers, or the last phone switch’s input port to output has been rung or a pre-deter- The most common local area net- port: used for wide area network mined time is reached work (LAN) technology, defined (WAN) connectivity. by the IEEE 802.3 standard, that › circular: starts with ringing the lets devices contend for access Gateway next number in the group for to a shared network. A device that interconnects networks each new call and continues with different, incompatible com- through the extensions in the Executive Override of Privacy munications protocols; specifically group until the call is answered Allows authorized users to override used to connect VoIP networks or a pre-determined time is the privacy feature and join an with analog phones, PBXs and reached existing two-party conversation. PSTN trunks. › longest idle: rings the phone in Extensible Markup Language H.323 the group that has been without (XML) A comprehensive standard of the A standard for storing and trans- a call for the longest time; con- International Telecommunication mitting data between systems; tinues to the next shortest idle Union (ITU) for realtime voice and allows data to be simply struc- until answered or a pre-deter- videoconferencing (including tured and shared between data- mined time is reached application sharing and white- bases and applications. boarding) over packet networks— Hybrid Mode A PBX operating mode in which LANs, WANs and the Internet. External Alerting Device some outside lines are grouped External bells, lights or gongs that Hands-Free together in pools while other lines can be placed in special locations A phone feature that allows users are assigned directly to buttons to facilitate the handling of calls. to answer incoming calls using an on telephones; users access out- External Page Interface integral speaker and microphone side lines by dialing a pool access Connections for an external loud without having to touch the phone. code (see key mode). speaker able to page one or more After a warning tone the phone zones. automatically goes off-hook. Hybrid PBX A PBX that is able to support both Fax (Facsimile) Hold (System, Exclusive) traditional analog or digital Transmission of a document over Allows users to put callers on hold phones as well as IP phones. telecommunications channels so that they can answer or initiate using a modem or ISDN. another call; calls can be placed I-Hold Indication on System Hold so that any other Provides multiline station users Fax Machine station user with the same line with an indication as to which A device that converts a document appearance can pick up the call, holding line is the one that they to a digital form suitable for sending or they can be placed on Exclusive placed on hold. and receiving over telecommuni- Hold so that only the station user cations systems and that allows Internet Engineering Task Force who put the caller on hold can (IETF) the printing of a “fax.” access the call. Organization responsible for the many Internet standards such as Flexible Station Numbering Hot Lines Allows users to customize their (or Manual Lines/House Phones) HTTP, SMTP and SIP. own phone numbering scheme and Allows a direct connection to be Internet Message Access Protocol feature and trunk access codes. automatically established to (IMAP4) another phone in the system A standard interface between an Foreign Exchange Office (FXO) when a user goes off-hook. email client and an email server An interface that connects local that displays headers with to/from calls to a PSTN central office or to Hunt Groups addresses and subject (rather than a PBX that does not support E&M A group of extensions accessed entire ) so that users can signaling. via a single number and allowing calls to be distributed to multiple selectively open and download their messages.

5 3COM® IP TELEPHONY ACRONYMS AND GLOSSARY

I—N

Incoming Call Group Key Telephone System (KTS) can also be calculated from delay, Allows central office trunk lines A standalone, inhouse telephony jitter and packet-loss measurements to be assigned to ring directly into system (often with relatively few to give an approximate score. A a group of stations without being users) in which all lines are score greater than 4.0 equates to routed through the attendant. directly connected to the tele- toll grade (see QoS). phone company central office, Message Waiting Interactive Voice Response (IVR) allowing users to place outside An automated system that can A feature that lights a message- calls without dialing “9” first; interact with a caller, providing waiting lamp to indicate receipt connected phones have buttons additional services such as direc- of a message (either voice- or text- for contacting on-premises phones tory lookup or call transfers by based) from an attendant or as well as for making outside calls. collecting information through another phone user. DTMF or ; LAN Telephony Modulator/Demodulator (Modem) often used in front of contact The convergence of voice and data A device that allows digital com- centers to collect customer specific traffic over a local area network. munication over circuits designed information before connecting the for voice by converting the data caller to an agent. Latency The sum of all the delays in an to suitable analog signals. Internal Paging end-to-end connection on a net- Multiple Trunk Groups Allows users to place page calls to work transmission. Allows central office trunk lines certain groups or all users on the to be assigned to pools or groups system via the telephone speaker. Least Cost Routing (LCR) A call routing plan, similar to Auto in applications that require more than one central office trunk line Intrusion Prevention System (IPS) Route Selection (ARS) that uses An inline security system for time-of-day, day-of-week and digit for the same function. detecting and eliminating network- translation information to find the Music-on-Hold borne application or infrastruc- least expensive routes for long- Audio signals (music, advertising ture attacks; uses deep packet distance calls. or other sounds) that are played inspection to identify and block to users on hold so that they transmission of malicious software know they are still connected. The analog component of the such as worms, viruses and trojan PSTN that connects subscribers MySQL horses. to a service. An open source database that is IP Telephony able to run under various versions Main/Satellite Service Voice services delivered over an of UNIX, Windows and Mac sys- Interconnectivity among multiple IP network. tems and is often used to store systems—such as those deployed and access provisioning system Integrated Services Digital in a business or school campus and subscriber feature data. Network (ISDN) environment—provided by special An international standard for trunks that allow almost transpar- Network-Branch eXchange (NBX®) switched, digital voice and data ent feature sharing with common A registered trademark of 3Com services based on 64 Kbps circuits. numbering plans and access codes. Corporation that identifies an IP telephony platform providing high- I-Use Indication Manual Signaling value converged services to small Provides multiline station users Allows users to send a manual and medium-sized organizations. with an indication of the line that signal or intercom tone to another is currently in use. phone by pressing a button. Network Call Processor (NCP) The heart of an IP telephony Jitter Meet-me Conference system that takes signaling from The variation in latency (delay) Conference bridge facility where end points, such as phones and for different packets to travel over parties can call a number at any- gateways, and forwards it to other a network; for real-time data such time and be placed in conference, endpoints based on dialing plans, as voice transmission, jitter must sharing a pool of conference ports routing rules and feature settings; be kept to a minimum. with no guarantee of availability; configured by an administrator to unlike scheduled conferences Key Mode provide the required IP telephony A telephone system operating with pre-booked resources; also features. known as ad-hoc conferences. model in which each telephone Night Service in the system has buttons for each Mean Opinion Score (MOS) Allows central office trunk lines available outside line; also known A commonly used measurement to be assigned in a fixed or flexi- as a square plan or a direct system of voice quality derived from ble configuration to different inward access (DISA) system (see multiple callers rating call quality, ringing locations after normal hybrid mode). thereby creating the mean opinion; business hours.

6 3COM® IP TELEPHONY ACRONYMS AND GLOSSARY

O—R

Off-Hook Post Office Protocol 3 (POP3) Proxy Server (SIP proxy) The state of a telephone that is Common protocol enabling email An intermediate device that ready to receive dialing digits, in clients to access email servers receives requests from a client the process of dialing or has a call over an IP network. and then initiates requests on in progress (in contrast with on- the client’s behalf; a SIP proxy Power Failure Transfer Phones hook); though normally deter- Allows specified central office follows the rules of the Session mined by whether the handset trunk lines to be connected Initiation Protocol (SIP)—stan- is off the cradle, with modern directly to certain phones in the dard RFC3261—to relay SIP speakerphones a device may go event of a system or commercial signaling onto other proxies “off-hook” automatically as the power failure. or clients. first digit is pressed or upon pressing a dial or send button Primary Rate ISDN (PRI) Public Switched Telephone Service provider connection that Network (PSTN) after entering digits. The term The name of the international net- delivers up to 24 (T1) or 30 (E1) stems from the days when a work of circuit-switched, automated switched data channels to a site. telephone handset was hung on telephone exchanges governed by Each channel supports voice or 64 a hook. International Telecommunication Kbps of data. Union standards. Off-Premise Extension Often a single-line phone, an off- Privacy Protects an existing conversation Q.931 site device that provides a user Signaling protocol for interfacing from accidental or intentional with the same capabilities and with service provider networks interruption by another user. features as on-site phones. over a T1 or E1 connection. Privacy Release (Non-Privacy) On-Hook Gives a phone user control of the Q.SIG The state of a telephone that is An open, standards-based protocol not ready for dialing or is in the privacy feature, enabling its release should the user want to that provides signaling and feature process of dialing and does not interoperability between PBXs. have a call in progress (in contrast allow another phone user with with off-hook). the same line appearance to join Quality of Service (QoS) the conversation. Used to describe the characteristics On-Hook Dialing required by a network in order to Private Automated Branch Allows station users to dial calls Exchange (PABX) handle real-time communications without lifting the handset. (See PBX) and data applications simultane- ously. Voice and video need QoS Outgoing Call Restrictions Private Branch Exchange (PBX) Administrator-defined limitations Also referenced as PABX, Private characteristics such as low delay, placed on users or extensions Automated Branch Exchange, an low packet loss and minimal jitter that prohibit numbers or number inhouse telephony switching net- which are tolerated by most data ranges; often used to block exter- work that allows phones to be applications. nal or international calling. used for internal calls or calls to Real-Time Protocol (RTP) phones outside the network via a An IP protocol for voice, video Packet Switching group of shared PSTN trunks. A communications method that and other real-time IP traffic that PBXs can support analog or digi- breaks-up data into small packets, provides timestamping and syn- tal services and capabilities such routes them through the network chronization information in the as least cost routing for outside and then reassembles them at the packet header to ensure proper calls, call forwarding, conference receiving end. reassembly when it reaches its calling and call accounting. destination. Personal Ringing Allows users to program their Private Lines Recorded Messages Also known as personal lines, phones with personal ringing Allows the system to connect enable assignment of a trunk line tones to distinguish one ringing callers to a recorded announcement to a specific button available only phone from another; may also be in conjunction with such features on certain telephones or to a spec- combined with Distinctive Ringing. as Night Service, Station Hunting, ified phone user. Automatic Call Distribution and Phantom Mailbox Auto Wakeup. A user profile that assigns a tele- Protocol Rules controlling phone number but without an Remote Access between devices (rather like associated telephone and automat- Allows specified users to dial into grammar in a language) for the ically connects all calls to its mailbox the system from an outside location purposes of exchanging of infor- within a voicemail system. and be permitted access to system mation. features and outside lines.

7 3COM® IP TELEPHONY ACRONYMS AND GLOSSARY

R—T

ReSerVation Protocol (RSVP) SIP Instant Messaging and T.38 A communications protocol for Presence Leveraging Extensions A standard for converting a fax notifying a router that bandwidth (SIMPLE) transmission from a circuit net- IETF SIP enhancements that needs to be reserved for real-time work to a packet network and provide a standardized method audio and video traffic to enhance vice versa. of delivering presence informa- transmission quality. tion and for supporting instant Telephony Saved Number Redial messaging (IM). Voice communications. Allows a user to dial a number and Simple Mail Transfer Protocol Telephony Application Program- save it so that it can be redialed at (SMTP) ming Interface (TAPI) a later time by pressing a button A standard that defines the mes- Call control and call manipulation or dialing an access code. sage format and transfer agent standards developed by Microsoft (MTA) needed for storing and and Intel for connecting Scheduled Conference A pre-scheduled, formal meeting forwarding emails using a variety to telephone services. conducted as a call between mul- of encoding methods to enable plain text, executable program Tenant Service tiple parties based on a predeter- Allows more than one organization and multimedia attachments. mined participant list and/or a (tenant) to share the same telephony scheduled start and end time. Simple Network Management system; through programming, Protocol (SNMP) each tenant can be restricted to Screen Pop A standard for sending messages A window that automatically opens its own central office (CO) trunks, between a management system attendant consoles and extension on a user’s computer when a pre- and managed devices; includes defined telephone event occurs; links; incoming calls are directed the ability to interrogate device to the appropriate tenant. for example, an incoming call status and configuration, change could generate a screen pop that parameters and receive alarms. Toll Restriction lists caller ID information. SNMP-compliant devices and Prevents specified phones from long distance toll calling (see out- Session Description Protocol agents store data about themselves (SDP) in management information bases going call restrictions). An IETF protocol that defines (MIBs) and return this data to the a text-based message format Toll Restriction Override SNMP requesters. Enables authorized users to tem- for multimedia session requests porarily override toll restriction between IP devices using stan- SIP Phone assignments on a specific phone dards such as Session Initiation An IP phone that uses Session by using a authorization code Protocol (SIP). Initiation Protocol (SIP)-based software for handling calls. or specific abbreviated dialing Secure Real-Time Transport numbers. Protocol (SRTP) Station Message Detail Recording A protocal that provides confiden- (SMDR) Traffic Measurement tiality, message authentication and Recording of data relating to Enables the system to generate replay protection and control of incoming and outgoing calls that feature and utilization reports on RTP traffic. enables phone activity reports to such statistics as number of calls, be produced detailing time, dura- duration of calls placed on differ- Security Alarm Interface tion and number dialed (see CDR). ent lines or the frequency that all Allows an alarm to trigger a tele- lines are busy. phone system alert whenever the Station Queuing/Trunk Queuing with Callback door is opened. Transmission Control Protocol/ Allows phone users who encounter Internet Protocol (TCP/IP) Session Initiation Protocol (SIP) a busy line to put themselves in a The family of protocols that An IETF application layer, text- queue and go on-hook until called supports communications via based protocol, based on HTTP back when the number they called the Internet and most corporate and MIME, that is used to handle becomes available (see camp-on networks. session establishment between busy). end points; enables interactive Transport Layer Security (TLS) T1 Enables signaling to be encrypted sessions to be established using A standard network connection, over the network. SDP to negotiate required predominantly in the U.S., that such as text, voice or video. can handle 24 channels with each Trunk channel able to handle 64 Kbps A communications channel Signaling between two intermediate switching Indicators that control transmis- of data or a voice call. The total points in a network; often used to sion of data or operation requests. circuit operates at 1.544 Mbps.

8 3COM® IP TELEPHONY ACRONYMS AND GLOSSARY

T—W refer to telephone channels between Voice Core eXchange (VCX™) Volume Control (for Microphone) major switching centers or con- A trademark of 3Com Corporation Allows adjusting the outgoing nections from a private network that identifies a SIP-based IP volume of a phone’s microphone into a public network. telephony platform providing on a hands-free call. high-value converged services Trunk-to-Trunk Connections to distributed organizations of Volume Control Also known as Unsupervised (for Speaker/Ringer) any size. Conference, allows a user to Allows adjusting the volume of the incoming call ringer and the establish a connection between Voicemail/Messaging System two outside lines without needing (VM/MS) phone’s speaker. to remain in the conversation. A standalone or networked system for receiving, storing and forward- Wi-Fi A location providing access to a Unified Messaging ing recorded voice messages. Provides access from a single inter- wireless LAN or the Internet. face—either a PC or phone—to Voice over Internet Protocol (VoIP) A technology that leverages IP Wi-Fi Phone voice, fax and email exchanges. A wireless handset that uses the data networks for transporting 802.11 standards to allow mobile User Datagram Protocol (UDP) voice calls. Connectionless, unreliable trans- telephony using Wi-Fi hotspots. port protocol used over IP where Voice Profile for Internet Mail error recovery is not required or (VPIM) A standard that enables software- is handled at a higher layer. Often based, seamless messaging between used to carry RTP. multiple sites and multiple voice Virtual Tie Lines messaging systems. Enable private connections between two or more telephony Voice Synthesizer An electronic or software-based systems (two business sites) over system that can generate voice an IP network. prompts or messages by simulating a human voice.

Visit www.3com.com for more information about 3Com secure converged network solutions. 3Com Corporation, Corporate Headquarters, 350 Campus Drive, Marlborough, MA 01752-3064 3Com is publicly traded on NASDAQ under the symbol COMS. Copyright © 2006 3Com Corporation. All rights reserved. 3Com, the 3Com logo and NBX are registered trademarks of 3Com Corporation. VCX is a trademark of 3Com Corporation. All other company and product names may be trademarks of their respective companies. While every effort is made to ensure the information given is accurate, 3Com does not accept liability for any errors or mistakes which may arise. All specifications are subject to change without notice. 200251-004 05/06

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