Service
Minimum
performance
*1
Resources per unit of
performance
No. of required DSP
resources
Free Resources
*5
47
*1
Minimum performance refers to the minimum number of simultaneous operations.
*2
Unified
Messaging operations include operations such as users (subscribers) accessing their mailboxes and outside callers leaving
messages in subscribers’ mailboxes.
*3
DSP resources are used when DSP Conference Priority is set to Preferential.
*4
The resources for Unified Messaging tones (used for Two-way Recording) are reserved automatically and cannot be released.
*5
Free Resources = DSP capacity – Total Reserved Resources, rounded to the nearest whole number.
If the PBX’s resources are reserved as shown in the example above, the resources required to meet the
numbers of operations listed in the "Minimum performance" column are guaranteed to be available. Note,
however, that for an operation such as a conference call, DSP resources are required for each individual
conference party in addition to the resources required for the conference CO line itself. Therefore, if all 40 VoIP
units as well as all free resources are being used, a new conference call cannot be established, even if sufficient
conference resources are available.
Conditions
• One-look Networking (® 14.1.4 One-look Network)
Resources are reserved individually for each PBX.
• The total number of resources provided by each type of DSP card is as follows:
– DSP S card: 63
– DSP M card: 127
– DSP L card: 254
PC Programming Manual References
9.5.1 PBX Configuration—[1-1] Configuration—Slot—Site Property—Main—DSP Conference—
DSP
Conference Priority
9.33 PBX Configuration
—[1-5] Configuration—DSP Resource
5.1.18 DSP Resource Usage
Description
To digitally process audio signals, such as a telephone call, the PBX must use a certain number of DSP (Digital
Signal Processing) resources. DSP resources are provided by the DSP cards installed in the PBX. Since there
are a limited number of DSP resources, no further operations (e.g., telephone calls, playing an OGM) can be
performed if all resources are being used.
The following list shows some of the basic operations that require DSP resources.
• IP extension call
• IP CO line call
• Conference
• Accessing the Unified Messaging system (including recording calls)
• OGM playback
• Echo canceller (for CO line-to-CO line analog calls)
For IP extension and CO line calls, the number of required resources differs depending on the codec (G.711
or G.729) used.
118 Feature Manual Document Version 2016-03
5.1.18 DSP Resource Usage