Traffic Engineering 623
NOTE
When troubleshooting voice networks, remember that the telephone company only responds to
problems beyond the demarcation point (the jack or other connection that ties your system to
the telephone company).
Consider the following issues when planning the voice aspects of your converged network:
·
Identify communities of interest. Identify groups or teams in your organization that tend
to exchange phone calls frequently.
·
Centralize digital service units (DSUs). Keeping DSUs in a centralized location makes it
easier to manage network connectivity. This approach also potentially shortens the
distance between nodes, reducing the cost of cable runs.
·
Use high-bandwidth media. Packetized voice traffic is highly sensitive to network
problems such as delay and congestion.
·
Install or upgrade to the fastest possible medium that you can afford--preferably fiber-
optic cable.
NOTE
If the cost of laying additional cable is prohibitive, a wireless networking solution might be
appropriate. Contact your Cisco sales representative for additional information.
Traffic Engineering Process
Traffic engineering for a VoIP network consists of the following steps, which are described in
the following sections:
Step 1
Forecast growth.
Step 2
Gather voice traffic data.
Step 3
Categorize traffic by group.
Step 4
Calculate the number of trunks.
Step 5
Choose the proper combination of trunks.
Step 6
Convert PSTN traffic to IP traffic.
Forecasting Growth
To ensure that your system can keep pace with your organization's needs, determine how many
phones are needed now and in the future.
87200333.book Page 623 Wednesday, August 22, 2001 1:41 PM