Call Control - Multi-Host Control

Basic Multi-Host Control lets you connect the with up to six hosts. One of the six connections is designated as the default. Each host can register to receive specific API messages from the Excel platform.

Call Control lets you customize the basic Multi-Host Control, to let you dynamically route API messages to the host.

Call Control components record which host sends a particular message, so that it can respond to that host with other messages for the call. The components can also test and report whether a host port is active or available.

Configuration

To enable Multi-Host Control, you must modify the PPL configuration, as described in the Customization section.

Customization

The CH component maintains information about the host port that can be used whenever a message is to be sent to the host. After each call, the host port is reset to the default: 0xFF, No Host Port Specified. So the host port must be set for every call. If the port is not set, the basic Multi-Host Control feature is used. Atomic functions 76–79 are used for host port information.

The valid values for the host ports are as follows:

0xFF: No Host Port Specified (default)

0x00: Port 3142

0x01: Port 3143

0x02: Port 3144

0x03: Port 3145

0x04: Port 3146

0x05: Port 3147

Atomic Functions

Using the four Atomic Functions below, you can modify the CH DSD to support Multi-Host.

• AF 76: Tests the real-time availability of the specified host port

• AF 77: Loads the current host port ID into the GPR. The PPL can then test the value.

• AF 78: Sets the current host port ID based on the value of the specified GPR. All messages initiated by Call Control for this channel are sent to this host port.

• AF 79: Stores the host port ID from the incoming host message (the host that sent it) into the GPR.