Preparation; Site Survey; System Design Considerations; Bandwidth Requirements And Call Capacity - Linksys SPA9000-NA Installation And Configuration Manual

3

Preparation

To ensure that the installation process goes smoothly, verify that you have the services, equipment,
and information described in the following sections . This chapter is essential reading before you
begin installing the equipment or configuring the system . Refer to the following topics:
"Site Survey" on page 19
•
"System Design Considerations" on page 19
•
"Network Setup Review" on page 20
•
"Deployment Scenarios" on page 22
•
"Services and Equipment" on page 25
•
"Downloading Firmware" on page 26
•

Site Survey

The site surveys consists of gathering relevant information about the customer, the existing
infrastructure, the network, the telephone equipment, and the available services . This survey helps
you to prepare for the installation of the LVS equipment (for example, ordering the LVS components
from the distribution channel) and to anticipate the design considerations . The site survey can be
conducted on the customer premises or remotely over the phone and e-mail .
Various site survey templates can be used . Appendix A, "Installation Workbook", contains a site survey
template example, used to fill the customer information .

System Design Considerations

When installing and configuring the LVS, it is necessary to analyze and meet some design
considerations to ensure the best quality and user experience . The design considerations cover
available bandwidth and quality of service .

Bandwidth Requirements and Call Capacity

The available connection bandwidth determines the maximum number of simultaneous calls that
the system can support with the appropriate audio quality . Before installing and configuring the
LVS components, use this information to determine the maximum number of simultaneous VoIP
connections that the system can support . For asymmetric connections, such as ADSL, the maximum
number of calls is determined by the upstream bandwidth . In general it is a good practice to use
no more than 75% of the total available bandwidth for calls . This provides space for data traffic and
helps ensure good voice quality .
The following table provides the approximate bandwidth budget for different codecs .
Codec Approximate bandwidth budget
for each side of conversation
G .711 110 kbps
G .726-40
G .726-32
G .726-24
G .726-16
G .729
Linksys Voice System Installation and Configuration Guide
2 calls
220 kbps
87 kbps 174 kbps
79 kbps 158 kbps
71 kbps 142 kbps
63 kbps 126 kbps
55 kbps 110 kbps
Preparation
Site Survey
4 calls 6 calls 8 calls
440 kbps 660 kbps 880 kbps
348 kbps 522 kbps 696 kbps
316 kbps 474 kbps 632 kbps
284 kbps 426 kbps 568 kbps
252 kbps 378 kbps 504 kbps
220 kbps 330 kbps 440 kbps
19