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Unified Conferencing

Overview

Unified Conferencing provides the following functionality:

• Mixed conferencing (µ-Law and A-Law, DSP-ONE card only)

• Unlimited Broadcast or "listen only" capability (µ-Law and A-Law)

• Ability to increase conference size dynamically

• Unified Conference algorithm

You can create, connect to, and delete a Unified conference by using the same techniques that are used for a Standard conference. But the Unified conference presents significant advantages over the Standard conference, including more channels, µ-Law and A-Law channels, and dynamic growth. Dynamic growth means that a Unified conference can automatically grow beyond its creation size when additional parties are connected to the conference.

Example

On the DSP-ONE card, an individual Unified conference can grow dynamically until the maximum Unified conference size of 25 is reached, or until all 31 channels on the DSP chip are used, whichever comes first. For example, a particular DSP chip can support one conference with 6 channels, a second conference with 10 channels, and a third conference with 15 channels, for a total of 31 channels.

All of the channels on this DSP chip are now in use, so none of the conferences on that chip can grow until one of these conferences frees a channel. If the 6-channel conference and the 10-channel conference were deleted, then 16 channels on that DSP chip would be freed. The remaining 15-party conference could then grow to the system-imposed maximum conference size of 25 parties, using 10 of the 16 freed channels. The six remaining channels on that DSP chip would then be available for new conferences.

Choosing Among Unified Conference Types

For the conference type Unified Dynamic Conference (0xN5), two local timeslots per conference are allocated to broadcast over the ring in both µ-law and A-law. In contrast, using one of the conference types 0xN7, 0xN8, 0xN9, or 0xNA, you can create a unified dynamic conference over the CSP that broadcasts over the ring in either A-law or µ-law, but not both. This way, only one local timeslot per conference is allocated to broadcast.

If you use µ-law exclusively, you should use one of these conference types:

• 0xN7 - Unified Dynamic, µ-law Broadcast

• 0xN8 - Unified Dynamic, µ-law Broadcast with DTMF Clamping

If you use A-law exclusively, you should use one of these conference types:

• 0xN9 - Unified Dynamic, A-law Broadcast

• 0xNA - Unified Dynamic, A-law Broadcast with DTMF Clamping

These two conference types behave the same way as the Unified Conference:

• Unified Dynamic, µ-law Broadcast

• Unified Dynamic, A-law Broadcast

These two conference types behave the same way as Unified Dynamic with DTMF Clamping:

• Unified Dynamic, µ-law Broadcast with DTMF Clamping

• Unified Dynamic, A-law Broadcast with DTMF Clamping

You receive a NACK of 0x2D (Incompatible PCM Encoding for Conference) if a channel from a remote node tries to connect 1-Way to a conference and the encoding type does not match the broadcast type set during the conference creation.

When the CSP creates a Unified conference, it places the conference on whichever DSP chip has the largest number of free channels at that moment. For example, if one DSP chip has 10 free channels and another has 20 free channels, the CSP places the new conference on the DSP chip with 20 free channels. This logic maximizes the opportunity for that conference to grow.

The call flow below illustrates how the host application can configure the CSP to use Unified conferencing. It also illustrates how to dynamically increase the size of a conference beyond the number originally specified in the Conference Create (0x004B) message.

Table 9-28 Configuring Unified Conferencing

For the Unified Dynamic Conference (0xN5) type, two local timeslots per conference are allocated to broadcast over the ring in both µ-law and A-law. In contrast, conference types 0xN7, 0xN8, 0xN9, and 0xNA, use only one local timeslot per conference to broadcast over the ring, in either µ-law or A-law, but not both. Users who use only µ-law do not need to allocate midplane ports for A-law, and vice versa.

PCM and companding standard used in North America and Japan to compress and expand the amplitude range of a signal before and after transmission. See A-Law
PCM and companding standard used in Europe to compress and expand the amplitude range of a signal before and after transmission. See µ-Law.
Digital Signal Processor
Negative acknowledgement to a message.
See Pulse Code Modulation.