1 8
T a l k S w i t c h U s e r G u i d e
Voicemail:
All Local Extension and Remote Extension Voicemail data is stored on the unit
where the extensions normally reside. For example, all greetings, directory names
and voicemail messages for extensions 121-128, 221-228 and mailboxes 420-429 are
stored on the TalkSwitch with Unit ID 2. If a unit is completely filled with voicemail
messages, new messages will not be stored on other units. The system will simply
not accept anymore messages for mailboxes belonging to that unit. If you need more
memory, TalkSwitch Memory Cards can be purchased from your reseller. You can also
use the Voicemail Memory Manager to view the memory usage of each TalkSwitch
unit and each mailbox.
2.6 Optimizing Your IP Network for VoIP
2.6.1
The Broadband Connection
For optimum quality of VoIP calls on your system, we recommend that you subscribe to
a high-speed broadband connection from your Service Provider. ‘Lite’ broadband
connections (typically 128 Kbps downstream and 64Kbps upstream) are not typically
suitable for simultaneous voice and data traffic. The limiting factor for a broadband
connection is typically the upstream bandwidth to the Internet Service Provider.
For example, if you have a typical 1Mbps ADSL connection from your service provider,
this usually means that you have an upstream bandwidth of approximately 380 Kbps.
Just because the service provider says that you have 380 Kbps upstream bandwidth
does not mean that the full 380 Kbps is available at all times. In fact, a conservative
approach is to estimate about half of the upstream bandwidth as being available. In
this case you could safely support 2 simultaneous G.711 calls or 4 simultaneous G.726
calls or 10 simultaneous G.729 calls. These estimates do not factor in other data traffic
on the network at the same time. With additional traffic on the Internet or private IP
network, the number of simultaneous calls supported by the link is reduced. For more
information on VoIP calling, see chapter 1.
