Routing Clear Channel VoIP Calls

The following examples show the host application initiating Clear Channel VoIP Calls using the VDAC-ONE card but without running SIP or H.323 software.

The following are two examples of API messages that cause the Excel platform to initiate a clear channel VoIP call. Even though the examples use different API messages, they perform the same function.

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00 34 00 2c 00 00 ff 00 01 0d 03 00 40 03 01 03 00 33 00 22 00 04 27 92 00 04 87 77 33 b2 27 93 00 04 00 00 17 84 27 94 00 04 87 77 33 b7 27 95 00 04 00 00 17 88

These messages require the host to manage the IP call signaling and to map the VDAC-ONE spans and channels to the correct IP resources (VDAC-ONE IP addresses and ports).

The following example involves host-to-host signaling (also called IP endpoint signaling).

1. A call from the PSTN comes into Excel platform A, which sends a Request for Service with Data message to Host A.

2. Host A notifies Host B (or an endpoint directly) of a call request using any protocol.

3. The call request contains the IP address and port number of a resource on the VDAC-ONE card (those IP addresses and ports must be managed by the host in this example).

4. The Host B side responds to the call request with the Host B side
parameters: IP address and port.

5. Host A issues a Route Control or Outseize Control message to Excel platform A supplying the local and remote VDAC-ONE IP and port address (as well as the correct span/channel) to initiate a VoIP clear channel call from the VDAC-ONE card.

6. Host B issues a Route Control or Outseize Control message to Excel platform B to complete the IP call.

Signaling technique where the full channel bandwidth is used for data transmission, while the framing and control bits (signaling) use a separate channel. No control or signaling is performed on this path. See B8ZS and ZBTSI.

Voice over Internet Protocol. The delivery of voice information in digital form in discrete packets rather than in the traditional circuit-committed protocols of the public-switched telephone network (PSTN).

Session-Initiation Protocol. A signaling protocol used for establishing sessions in an IP network. A session could be a simple, two-way telephone call, or it could be a collaborative multi-media conference session.

ITU-T standard defines a set of call control, channel setup, and codec specifications for transmitting real-time voice and video over networks that do not offer guaranteed service or quality of service.

Outgoing call setup during real-time call processing on a specific channel.

Internet Protocol. Part of the TCP/IP family of protocols used to route messages and tracks the addresses of nodes.

An H.323 terminal or gateway, or MCU. An endpoint can call and be called. It generates and/or terminates the information stream.

Public Switched Telephone Network

A computer, attached to the Excel platform through an RS-232 or Ethernet link, from which you run the telecommunications application that controls the Excel platform.