Cisco Voice over IP (CVOICE)

Introducing Digital Voice Ports (Performing Call Signaling over Digital Voice Ports) Part 6

Configuring a BRI Trunk Example In this example, you have been asked to configure a BRI connection to the PSTN according to the following network requirements. Figure 4-18 presents the topology used in this example. Figure 4-18 ISDN BRI Configuration Topology Example The requirements are as follows: ■ Because the ISDN switch is located in […]

Using QSIG for Digital Signaling (Performing Call Signaling over Digital Voice Ports) Part 1

QSIG is an extension of ISDN and supports enterprise-class call features, such as signaling message-waiting indicators and call back. This section describes the characteristics of QSIG and how to implement QSIG trunks on a Cisco IOS gateway. QSIG Overview QSIG is a variant of ISDN Q.921 and Q.931 ISDN D-channel signaling for use in devices […]

Using QSIG for Digital Signaling (Performing Call Signaling over Digital Voice Ports) Part 2

Verifying QSIG Trunks To display information about the PRI interface controller, use the show controllers command, as demonstrated in Example 4-21. Example 4-21 show controllers Command Use the show isdn status command, as illustrated in Example 4-22, to verify the ISDN Layer 1 is ACTIVE and the Layer 2 state is MULTIPLE_FRAME_ESTABLISHED. If these conditions […]

Configuring H.323 (Examining VoIP Gateways and Gateway Control Protocols) Part 1

To provide voice communication over an IP network, Real-time Transport Protocol (RTP) sessions are created. These sessions are dynamically created and facilitated by one of several call control procedures. Typically, these procedures also embody mechanisms for signaling events during voice calls and for managing and collecting statistics about the voice calls. Several types of protocols […]

Configuring H.323 (Examining VoIP Gateways and Gateway Control Protocols) Part 2

H.323 Network Components Figure 5-4 shows some typical terminal devices in an H.323 network. Figure 5-4 H.323 Network Components Components of an H.323 network include the following: ■ Terminals ■ H.323 ■ H.324 ■ Gateways ■ Cisco Unified Border Elements (Cisco UBEs), also known as session border controllers ■ Gatekeepers ■ MCUs The following sections […]

Configuring H.323 (Examining VoIP Gateways and Gateway Control Protocols) Part 3

H.323 Call Establishment and Maintenance Although H.323 is based on the concepts of a distributed call control model, it often embodies centralized call control model concepts. Calls can be established between any of these components: ■ Endpoint to endpoint: The intelligence of H.323 endpoints allows them to operate autonomously. In this mode of operation, endpoints […]

Configuring H.323 (Examining VoIP Gateways and Gateway Control Protocols) Part 5

Fax Relay Example Figure 5-14 shows a topology example for a voice service VoIP and dial-peer configuration of a voice gateway that is configured for fax relay. Figure 5-14 H.323 Fax Relay Configuration Topology Example This scenario requires a company’s headquarters in San Jose to be able to fax to its Austin office using T.38 […]

Implementing MGCP Gateways (Examining VoIP Gateways and Gateway Control Protocols) Part 1

The MGCP enables the remote control and management of voice and data communications devices at the edge of multiservice IP packet networks. Because of its centralized architecture, MGCP overcomes the distributed configuration and administration problems inherent in the use of protocols such as H.323. This section describes how to configure MGCP on a gateway and […]

Implementing MGCP Gateways (Examining VoIP Gateways and Gateway Control Protocols) Part 2

Package Types A call connection involves a series of events and signals, such as off-hook status, a ringing signal, or a signal to play an announcement, that are specific to the type of endpoint involved in the call. MGCP groups these events and signals into packages. A trunk package, for example, is a group of […]

Implementing MGCP Gateways (Examining VoIP Gateways and Gateway Control Protocols) Part 3

Configuring Fax Relay with MGCP Gateways Figure 5-22 and Example 5-9 show an MGCP configuration of a voice gateway that is configured for T.38 fax support. Figure 5-22 Fax Pass-Through and Relay with MGCP Gateways Topology Example 5-9 Fax Pass-Through and Relay with MGCP Gateways Example This scenario requires a company’s headquarters in San Jose […]

← Previous Entries

Next Entries →