VoIP Terms

bearer bandwidth limit (BBL)

Maximum bandwidth available for voice traffic on an interface when dynamic call admission control is configured on the interface. See also dynamic CAC.

call admission control (CAC)

Method of limiting voice traffic over a particular link in a network. See also dynamic CAC.

centralized automatic message accounting (CAMA)

Recording of toll calls at a central point.

direct inward dialing (DID)

Feature of a trunk line that allows incoming calls to be routed directly to selected stations without help from an attendant.

direct outward dialing (DOD)

Feature of a trunk line that allows outgoing calls to be routed directly without help from an attendant.

direct inward and outward dialing (DIOD)

Feature of a trunk line that allows both incoming and outgoing calls to be routed directly without help from an attendant. See also direct inward dialing (DID) and direct outward dialing (DOD).

Disk-on-Key

Memory device (stick) that plugs into a USB port to load a complete JUNOS configuration with VoIP onto a Services Router. You must first use an Electronic Preinstallation Worksheet (EPW) to download the configuration to the Disk-on-Key device. The EPW and Disk-on-Key device provide an alternative method to configure the router for VoIP.

dynamic CAC

Application that blocks calls on a WAN interface when the bandwidth is exhausted. See also call admission control (CAC).

Electronic Preinstallation Worksheet (EPW)

Customized Microsoft Excel spreadsheet used with a Disk-on-Key USB memory stick to configure VoIP on a Services Router. You download the EPW from an Avaya Web site.

emergency transfer relay (ETR)

Feature that provides an emergency link between the telephone connected to the first LINE port on the TGM550 and the trunk connected to the TRUNK port on the TGM550 if power is disconnected from the Services Router or if the TGM550 becomes unregistered from its Media Gateway Controller (MGC).

IEEE 802.1p standard

IEEE standard for a Layer 2 frame structure that supports virtual LAN (VLAN) identification and class-of-service (CoS) traffic classification.

IEEE 802.3af standard

IEEE standard that defines a method for powering network devices through an Ethernet cable. Also known as Power over Ethernet (PoE), this standard enables remote devices (such as VoIP telephones) to operate without a separate, external power source. See also Power over Ethernet (PoE).

ITU H.248 standard

International Telecommunications Union (ITU) standard for communication between a gateway controller and a media gateway.

ITU H.323 standard

International Telecommunications Union (ITU) standard for packet-based multimedia communications over networks that do not guarantee class of service (CoS), such as IP networks. H323, modeled after ISDN PRI, is the standard for voice over IP (VoIP) and conferencing.

Media Gateway Controller (MGC)

Avaya media server that controls the parts of the call state that pertain to connection control for media channels in a media gateway. The MGC is the controlling entity in an H.248 relationship.

Power over Ethernet (PoE)

Electrical current run to networking devices over Ethernet Category 5 or higher data cables. No extra AC power cord or outlets are needed at the product location.

public switched telephone network (PSTN)

The public worldwide voice telephone network.

standard local survivability (SLS)

Configurable software feature that enables a TGM550 to provide limited Media Gateway Controller (MGC) functionality when no link is available to a registered MGC.

time-division multiplexing (TDM)

A form of multiplexing that divides a transmission channel into successive time slots.

TGM550

Avaya Telephony Gateway Module. Avaya VoIP H.248 media gateway module installed in a Services Router along with one or more Telephony Interface Modules (TIMs) to connect VoIP and legacy analog telephones and trunks over IP networks. Only the TGM550 has an interface configurable through the J-Web interface or JUNOS CLI. The TIMs are configured and administered from the TGM550 CLI.

TIM510

Avaya E1/T1 Telephony Interface Module. Avaya VoIP module installed in a Services Router to provide an E1 or T1 trunk connection over the Internet to a telephone central office (CO). A TIM510 is configured and administered from a TGM550 installed in the same router.

TIM514

Avaya Analog Telephony Interface Module. Avaya VoIP module installed in a Services Router to connect individual telephones or trunk lines to the Internet. A TIM514 is configured and administered from a TGM550 installed in the same router.

TIM521

Avaya BRI Telephony Interface Module. Avaya VoIP module installed in a Services Router to connect ISDN Basic Rate Interface (BRI) trunk lines to a telephone central office (CO) over the Internet for data or voice transmission. A TIM521 is configured and administered from a TGM550 installed in the same router.