Nortel BCM 3.7, Manual

Page: 617 / 1004

Rules for managing the MSC resources 617
Programming Operations Guide
DSP resources rules
The number of DSP resources you have depends of the number of type of MS-PEC you have
installed. For information about how to determine the MS-PECs you have, refer to
“Viewing the
MS-PEC configuration” on page 627 .
For the purposes of calculating DSP resources, we can estimate the relative power of each
configuration as follows:
• 4 MS-PEC I 24 units
• 2 MS-PEC III 64 units
• 4 MS-PEC III 128 units
The number of DSP resources you need depends on the features and type of codec you are using.
• Dial-on-Demand WAN uses 1 unit for each 64Kbit/s channel
• Voicemail, IVR, and call center use 1 unit for each active session
• Fax uses 6 units for each active fax channel
• IP telephone or IP trunk using G.711 codec uses 1 unit
• IP telephone or IP trunk using G.729 codec uses 3 units
• IP telephone or IP trunk using G.723 codec uses 4 units
Voice bus path
There are 62 voice bus paths available on Business Communications Manager.
• Voicemail and IVR use one voice bus path for each active session.
• Dial-on-Demand WAN uses one voice bus path for each 64Kbit/s channel that is active.
• IP telephones and IP trunks require one voice bus path when ever a media channel is required.
Note:
Some of the DSP resource units listed above are rounded to the nearest whole
number. This is done to ease the calculation of the DSP resources you require. To
calculate more accurate DSP requirements, use the DSP resource units in shown in the
following table.
Table 144 DSP resource requirements
Feature or codec Resource units on a MS-PEC I Resource units on a MS-PEC III
G.729 3 2.75
G.723 4 4.2
Fax 5 6
T.38 IP Fax 5 6
IVR Fax 6 6