Nortel BCM 3.7, Manual

Page: 618 / 1004

618 Determining the MSC resources you require
N0008589 3.3
Media gateways
One media gateway is required for each call:
• from an IP telephone to an analog or digital telephone
• from an IP telephone using a PSTN line
• from an analog or digital telephone using an IP trunk
Determining the MSC resources you require
The following 20 questions are designed to help determine how many MSC resources you require.
Based on the answers to these questions you can calculate the number of signaling channel
s , media
channels, voice bus paths and DSP resource units you need. Use the table in “Evaluation” on page
624 to determine the configurations.
ISDN WAN (Dial-up/Nailed-up)
As you answer the following questions, record your answers in the table in “Record of required
MSC resources” on page 623 .
1 What is the maximum required WAN bandwidth?
The range is 0 to 1 Mbit/s (16 x 64 kbit/s) in 64 kbit/s increments.
If the answer is more than zero:
• add 27 to the signaling channel count
• add 27 to the media channel count
2 What is the required WAN bandwidth during peak periods?
The range is 0 to the maximum bandwidth you entered in question 1.
For each 64 kbit/s of bandwidth:
• add 1 to the voice bus time slot count
• add 1 to the DSP resource unit count
Note: In the following questions, “peak periods” refers to the periods of time when there
is the highest overall activity. It is necessary to consider the resource requirements for
“peak periods” to determine if available voice bus paths and DSP resources meet your
resource requirements at all times.