What Happens If The Power Goes Out Or If The Ip Network To Voip Fails; Can A Firewall Prevent Voip Calls From Passing Through; What Is Sip; What Is A Vpn - Talkswitch CT.TS005.003904 User Manual

• Use high-speed connections on both ends of the call
VoIP requires a broadband connection to support simultaneous calls. Please visit the support
section of our site at http://global.talkswitch.com to determine what your Internet
connection can support. Good quality VoIP is not possible over a dial-up modem connection.
• Choose the right codec for your location
• The default codec is G.729 (8 Kbps), using approximately 25 Kbps bandwidth upstream
and 25 Kbps bandwidth downstream for each call. G.729 provides very good call quality
while minimizing bandwidth usage.
• The G.726 (32 Kbps) codec is a better quality solution compared to the G.729 codec.
However, it requires more bandwidth per call. A G.726 call typically requires 50 Kbps
bandwidth upstream and 50 Kbps bandwidth downstream for each call.
• The G.711 (64 Kbps) codec provides the best voice quality. The trade-off is the
bandwidth requirement. G.711 calls typically require up to 100 Kbps bandwidth
upstream and 100 Kbps bandwidth downstream.

What happens if the power goes out or if the IP network to VoIP fails?

To ensure a reliable network connection, all elements of the VoIP network should be connected
to back-up power supplies (UPS). These elements should include LAN switches, routers, firewalls,
broadband connection devices (i.e. cable modems, DSL modems), and VoIP devices. If the power
goes out at the Internet Service Provider, no VoIP calls can be made. Calls can still be placed over
the telephone lines.

Can a firewall prevent VoIP calls from passing through?

The purpose of a firewall is to control what kind of traffic enters and leaves your network. The
TalkSwitch unit is designed to allow VoIP calls to traverse firewalls properly. To allow VoIP calls
to pass through your firewall, you may need to use the port forwarding feature on your firewall.

What is SIP?

The Session Initiation Protocol (SIP) is a signalling protocol used for establishing sessions in an
IP network. A session could be a simple 2-way telephone call or it could be a collaborative multi-
media conference session.
Over the last couple of years, the Voice over IP community has adopted SIP as its protocol of
choice for signalling. SIP is an RFC standard (RFC 3261) from the Internet Engineering Task
Force (IETF). This is the body responsible for administering and developing the mechanisms that
comprise the Internet.
The IETF's philosophy is simplicity: specify only what you need to specify. SIP just initiates,
terminates and modifies sessions.
TalkSwitch phone systems use the Appello® SIP Stack for VoIP communications. The Appello®
SIP Stack was developed by TalkSwitch, a division of Centrepoint Technologies Inc.

What is a VPN?

VPN stands for Virtual Private Network. It is a means of having the advantages of a private
network on a shared public infrastructure like the Internet.
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