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Definitions
Software Conference: Default conference option for UC500. Software conferencing enables 3-party ad-hoc conferencing capabilities and is enabled by default for a maximum of 8 conferences (8x3).
Hardware Conference: Conferencing option that makes use of a DSP for audio mixing. Two types are available on the UC500, ad-hoc and meet-me. When hardware conferencing is enabled on the UC500, ALL conferencing sessions (including 3-way calls) will be hardware-based.
- An Ad-hoc conference is an unscheduled conference. It occurs when a third party is added into any conversation by the participants by use of the conference softkey or access code. The ad-hoc initiators can add/delete/drop participants to/from the conference. The conference falls back into a normal call when there are only two parties in the conference. A maximum of 8 users can be in a hardware ad-hoc conference or less depending on how configured.
- A Meet-Me conference is a conference that is initiated by a conference initiator by using the meet-me softkey. Only an IP Phone user can start a meet-me conference. Once the conference is initiated, anyone is allowed to join the conference by dialing into the conference number (internal DN or external DID). Additionally, the meet-me conference initiator is allowed to add or delete parties to/from the conference. A maximum of 32 users allowed in a meet-me or less depending on how configured.
DSP or Digital Signal Processor: A DSP is a dedicated Hardware component used to process digital voice for a variety of functions, such as codec conversion (also known as "transcoding", for example G.711 to G.729 conversion), audio mixing (for conferencing), voice quality processing (echo cancellation, jitter buffers, etc.), fax signal demodulation (for fax to fax transmissions and also fax to email/email to fax implementations) and voice packetization (for transport over packet network technologies, such as VoIP).
Packet Voice Digital Signal Processor (DSP) Module (PVDM2): Microprocessor included with every UC500. The DSP module on a UC500 is a non-replaceable part. The PVDM2 included with the UC500 has the following characteristics:
Table 1: Available DSPs Per Platform
| Platform | PVDM2 | Number of DSPs |
|---|
| UC520 8/16U | 1x PVDM2-32 | 2 |
| UC520 24/32/48U | 1x PVDM2-64 | 4 |
| UC540 | 1x PVDM2-64 | 4 |
| UC560 | 2x PVDM2-64 | 8 |
Hardware Conferencing
When hardware conferencing is enabled CCA statically allocates the following number of DSPs for conferencing:
Table 2: Available DSPs For Conferencing
| Platform | Number of Configured Voice T1/E1's | DSPs Allocated for Conferencing |
|---|
| UC520 8/16U | 1 | Not supported |
| UC520 8/16U | 0 | 1 |
| UC520 24/32/48U | 1 | 1 |
| UC520 24/32/48U | 0 | 2 |
| UC540 | 1 | 1 |
| UC540 | 0 | 2 |
| UC560 | 0 | 4 |
| UC560 | 1 | 4 |
| UC560 | 2 | 3 |
Meet-Me
For Meet-me conferencing each DSP can support a maximum of 64 G.711 conference streams (single-mode) or 16 G.711/G.729a/G.729 conference streams (mixed-mode). The maximum number of conference participants in a single Meet-me conference call is 32. Here are the following configuration options:
Table 3: Single-Mode (G.711) Meet-me Conference
Maximum Multi-Party Sessions | Maximum Meet-Me Partipants | 1 DSP |
|---|
| 2 | 32 | 64 streams |
| 4 | 16 | 64 streams |
| 6 | 8 | *48 streams |
| 8 | 8 | 64 steams |
*A configuration of 6 conference sessions with a maximum of 8 participants each would be underutilizing the DSP resource
Table 4: Mixed-Mode (G.711/G.729a/G.729) Meet-me Conference
Maximum Multi-Party Sessions | Maximum Meet-Me Participants | 1 DSP |
|---|
| 1 | 16 | 16 streams |
| 2 | 8 | 16 streams |
For a UC500 platform that has more than 1 DSP for hardware conferencing (refer to Table 2) the number of sessions would increase by the number of DSPs available. E.g. A UC560 with two voice T1’s in single-mode (G.711) can support up to 6 simultaneous conference sessions (2 sessions x 3 DSPs) of a maximum of 32 participants in each conference. Note that the maximum number of Meet-me participants remains unchanged.
Ad-hoc
For Ad-hoc conferencing the maximum number of conference participants is 8. This value is not configurable as in the case of Meet-me conferencing. Keeping in mind that a single DSP can support a maximum of 64 G.711 conference streams (single-mode) or 16 G.711/G.729a/G.729 conference streams (mixed-mode), we have the following options:
Table 5: Single-Mode (G.711) Ad-hoc Conference
Maximum Conference Sessions | Maximum Ad-hoc Participants | 1 DSP |
|---|
| 8 | 8 | 64 streams |
Table 6: Mixed-Mode (G.711/G.729a/G.729) Ad-hoc Conference
Maximum Conference Sessions | Maximum Ad-hoc Participants | 1 DSP |
|---|
| 2 | 8 | 16 streams |
