CSP Conferencing

CSP Conferencing allows channels on any CSP node to be connected to a conference. The conference can use a single DSP resource located on any node on the ring. All of the conferencing capabilities of a single CSP are supported.

• The conference node has available CSP conferencing timeslots to the remote channel onto its local bus.

The EXNET-ONE card (EXS-XIO-1201) and the DSP-ONE card are required for CSP conferencing.

A space on the TDM bus that may or may not contain voice or data information. The CSP 2090 has 2,048 timeslots; the CSP 2040 has 1,024.

A local timeslot allocated for CSP Conferencing and assigned to a channel in a conference.

The only special configuration required for CSP Conferencing is the allocation of available timeslots on each node for conferencing, using the EXS Node Configure message. When these available timeslots are allocated, conferences are created and set up the same way as they are for a single CSP. Information about timeslot configuration is stored on the Matrix Controller card(s) and is maintained even if the Matrix Controller card is switched over.

To allocate timeslots for CSP Conferencing, use the EXS Node Configure message with a value of 0xFFFF in the Number of Timeslots field. Entering any other value returns a response status of Invalid Value for Entity.

When a conference is created, timeslots are allocated for all parties in the conference (local and remote channels) and broadcasting if broadcasting is supported by the conference type. A Standard Conference requires one additional timeslot, and a Monitor Conference requires two additional timeslots.

Important! There must be at least 256 unlicensed timeslots available to allocate any timeslots.

The number of timeslots used by line cards is determined by the number of spans supported by the card, not by the number of spans assigned by the host.

To calculate the number of timeslots available for EXS conferencing in your CSP, use the following formula:

Total Number of free Timeslots = (2048 minus (the number of T1 spans multiplied by 24) minus (the number of E1 spans multiplied by 32) minus (the number of J1 spans multiplied by 32) minus (the number of VDAC spans multiplied by 32) minus (the number of DS3 spans multiplied by 24))

For example, you would calculate free timeslots on a node with three
T-ONE-16 line cards as follows:

Card:	Spans * Channels/Span	= Time Slots Used
ST1LC 8-span	8 * 24	192
SE1LC 8-span	8 * 32	256
T-ONE 8-span	8 * 24	192
T-ONE 16-span	16 * 24	384
E-ONE	16 * 32	512
DS3	28 * 24	672
VDAC-1 w/2 modules	(2 * 32) + 16 odd channels	80
VDAC-1 w/4 modules	5 * 32	160
VDAC-2 profile 1	32 * 32	1024 (port consuming mode)
VDAC-2 profile 2	16 * 32	512 (port consuming mode)

If the allocation is successful, a positive acknowledgment (ACK) is returned, with data bytes that indicate the number of timeslots allocated. If the allocation is unsuccessful, a negative acknowledgment (NACK) is returned, with data bytes that indicate the number of unallocated timeslots available for CSP conferencing. To successfully allocate timeslots after a negative acknowledgment, re-issue the message with the number of free timeslots that were indicated in the response.

This example shows a four-party standard conference established on a node where three parties are local and one party is on a remote node.

The conference requires six CSP Conferencing timeslots on the local bus, in addition to the three physical timeslots initially assigned to the local channels in the line card:

• Three physical time slot are used on the line card (T1/E1, which is already allocated)

• Two for conferencing to broadcast to the ring (one for u-law, one for a-law) Note: only one time slot is needed if you only use a-law or u-law.

If a line card is inserted or removed, the number of timeslots available for an CSP Conference changes, and the host receives the CSP Node alarm, Available CSP Conferencing Timeslot Count Changed. The data in the alarm indicates the new timeslot count.

When the number of free timeslots decreases to a threshold pre-set by the host, the host receives a General Alarm of Resource Utilization Threshold Reached. The Data field in the alarm indicates a Resource Type of CSP Conferencing Timeslots.

The host sets the upper and lower threshold of the alarm, with the System Configuration message, are as follows:

Configuration Type	Resource Threshold (0x07)
Data[0]	Resource Type: Conferencing Timeslots (0x01)
Data[1, 2]	Number of Assigned Timeslots to Generate an Alarm Cleared
Data[3, 4]	Number of Assigned Timeslots to Generate an Alarm

You can query the CSP Conferencing Resources with the System Resource Usage Query message, which reports the following:

The System Resource Utilization Query message reports the number of timeslots currently used by CSP conferencing. You can calculate the number of free timeslots by subtracting this number from the total number of timeslots that are allocated for CSP Conferencing.

As with a single CSP, conferences are created using the Conference Create message.

You can use the Conference Type field in the Conference Create message not only to specify a conference type, but also to specify the channels and DSP resources to be used to establish the conference. The lower nibble (the right-most four bits) of the Conference Type field indicates the conference type. The upper nibble (the left-most four bits) indicates which channels and DSP resources can be used to establish the conference.

This nibble indicates whether the conference can be established on the designated node only, or on any node with an available DSP resource. The nibble also indicates whether the channels in the conference must be located on the designated node, or on any node with available channels. The options are listed below:

• Only a DSP residing on the node that receives the Conference Create message can be used to establish the conference. If no DSP is available on the node, a Response Status is returned of No DSP Resource Available.

• If available, a DSP located on the node receiving the Conference Create message is used to establish the conference. If no DSP is available on the node, a remote node is chosen, based on the number of available resources.

The response to the Conference Create message contains a two-byte Conference ID. Within this Conference ID, the bits 2-4 (zero based) of the MSB indicate the Logical Node ID of the Conference Node.

You can use the System Configuration Query message to query the currently-active conference IDs for each node.

The conference exists until the host specifically deletes it, or until a system event deletes it, as described in the System Events section below.

Please refer to the Conference Create 0x004B message in the API Reference for more information.

This section describes the following effects of various system events on CSP Conferencing, and any required host interaction:

If a line card is removed or reset, any channels on the card involved in a conference are purged from the conference.

If a line card is removed or inserted, the number of timeslots available on a node for CSP Conferencing is dynamically updated. The host is informed of the new number of available timeslots with an Alarm message.

If inserting a line card brings the number of timeslots available for CSP conferencing below the number assigned to CSP conferences, some channels connected to conferences are purged. This situation is a concern only for systems with many line cards installed and many CSP conference connections.

You can query the use of CSP conferencing resources, with the System Resource Utilization Query message.

When a DSP-ONE card is inserted into a node, it must be configured for conferencing with the DSP SIMM Configure message before it can be used to establish a conference.

If a DSP-ONE card is removed from a node, any conferences active on the card are deleted and all channels associated with the conference are purged.

If the conferencing node has a redundant Matrix Controller, and the active Matrix Controller is removed or reset, all conferences and conferees are maintained through the switchover.

EXNET® ring failure is defined as a node becoming inaccessible to the ring due to:

All inter-nodal conferees are purged. Local connections for conferences in each node are maintained.

If communication between nodes fails, conferences on the Conference Node are maintained with any local channels connected to the conference. Conferees on remote nodes are purged from the conference.

Digital Signal Processor

Excel's open architecture, proprietary, 1.3 Gbps fiber optic network using a packet-based protocol.

See Time Division Multiplexing.

Digital communications link - voice, data, and video at a 1.544 Mbps rate (24 64 Kbps channels)

A digital communications link - voice, data, and video at a 2.048 Mbps rate; 30B/2D or 31B/1D (ISDN); non-North American version of T1.

Range of channels provided by T1 or E1 transmission service. A physical span is a group of channels taking up a single physical wire. A logical span is a group of channels taking up less than a single logical wire, or carried over more than one physical wire.

Positive acknowledgment to a message

Negative acknowledgement to a message.

Most Significant Bit

In PPL, a condition that, when met, drives a state machine (PPL Component) from one state to another, by invoking an associated Primitive. In PPL files, an Event is marked by an arrow and text.

The protocol used in most local area PC networks. Typically, most Ethernet networks support data transmission speeds up to 10 Mbps, but 100 Mbps is also possible.