Dialogic 6.2 manual Channel Numbering

The Bfv API Functions

Channel Numbering

The Bfv API uses two numbering schemes when referencing channels within a system. One is the unit number or ordinal channel number; the other is the logical channel number.

The unit number is a number range 0…n-1, where n is the number of channels in the system. The BfvLineAttach function uses the unit number in its argument and returns a pointer to the BTLINE structure, providing a means to reference the channel in future function calls. For example, a system comprising two 60-channel modules would have a unit number range of 0-119. The module that had the firmware downloaded first would contain the channels starting from 0.

The logical channel number is used together with the module number to reference a work channel (also called a hardware channel) in a system. The BfvSessionAttach function uses the module and logical channel numbers in its arguments. Logical channels not only include work channels traditionally considered to be channels, but also administrative channels. The work channel number range for logical channels is 2…n+1, where n is the number of work channels on this hardware module.

Each module has a unique module number. For example, the same system comprising two 60-channel modules could have the following configuration:

„First module: Module 2, work channels 2-61

„Second module: Module 3, work channels 2-61

Each virtual module has 120 channels (the maximum allowed in a system).

The BfvSessionAttach function also returns a BTLINE structure; other functions that accept a BTLINE structure as an argument can use either that returned from BfvLineAttach or BfvSessionAttach. When detaching, use the corresponding detach functions BfvLineDetach or BfvSessionDetach.

Unit numbers and BfvLineAttach are typical of our legacy product.

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