The G.726 (32Kbps) CODEC is a better quality solution compared to the G.729 CODEC. It does, however, require more bandwidth per call. A G.726 call will typically require 50Kbps bandwidth upstream and 50Kbps bandwidth downstream for each call.
The G.711 CODEC provides the best voice quality. The tradeoff is the bandwidth requirement. G.711 calls typically requires up to 100Kbps bandwidth upstream and 100Kbps bandwidth downstream.
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. In fact, a conservative approach is to estimate just over 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.
If the power goes out, does the VoIP network stay up?
To ensure a reliable network connection, all elements of the VoIP network should be connected to
What happens to VoIP if the IP network fails?
If the connection to the IP network is lost, it will not be possible to make VoIP calls. Calls can still be placed over the regular phone lines.
I have a firewall and heard that it can prevent VoIP calls from passing through. Is this true?
The purpose of a firewall is to control what kinds of traffic enter and leave your network. The TalkSwitch
TalkSwitch |
| |||||
Format | Type | Unit 1 | Unit 2 | Unit 3 | Unit 4 | |
RTP (voice): | UDP | 6000 | - 6006 | |||
SIP (signaling): | UDP | 5060 | (This port is mapped to only one unit) | |||
ii
TalkSwitch User Manual
