What is VoIP?
VoIP stands for Voice over Internet Protocol
, a general term for a family of transmission technologies, used for delivery of voice communications over IP networks (such as the Internet or other packet-switched networks.)
What is SIP?
SIP stands for Session Initiation Protocol
, a signalling protocol used for setting up and tearing down multimedia communication sessions for VoIP
. TFone VoIP Numbers
protocols to initiate phone calls. Other signalling protocols (ie. IAX) will be implemented at a later stage.
Can I send and receive fax documents over VoIP?
TFone does not limit or block fax traffic over our network.
However, if you wish to transmit fax signals over the VoIP network, you should use the G.711 ulaw (PCMU)
codec (highest quality but uses the most bandwidth). TNZ Group cannot guarantee the quality of fax documents transmitted using TFone.
Alternatively, TNZ Group offers PSTN Fax Numbers (TFaxIn Numbers
) for the most reliable fax transmissions possible. See the TFax Service
for details on fax to email and email to fax. TNZ Group will issue you a dedicated internet fax number that offers guaranteed delivery and excellent quality at a low cost, right into your email inbox!
We are currently offering a Fax-In plan for TFone customers only. Signup for a TFone VoIP Number and you can also receive a TFax Number on a special plan! See details here: Fax-In 500
Can I send and receive SMS/TXT messages over VoIP?
Sorry, at this stage TNZ Group does not offer SMS messages over VoIP. See the TSMS Service for details on SMS / TXT messaging
over the internet.
Do you provide internet connections?
We prefer to let our customers choose their own Internet Service Provider (ISP), however for large VoIP installations we can provide direct HSNS or Fibre circuits.
Each Fibre or HSNS installation will need to be quoted specifically, so please contact a TNZ Group representative for more information. An example of the contractual agreement for this service can be found here: HSNS-Fibre Delivery of Service Agreement
Which VoIP / SIP audio codecs do you support?
TFone VoIP Number supports number of codecs as per below:
- G.711 ulaw (PCMU)
- G.711 alaw (PCMA)
Ocassionally we have issues making over three calls at the same time reliably over an ADSL connection. Why?
Can we increase the number of concurrent calls?
If you are using the G.711 ulaw (PCMU)
codec, G.711 ulaw requires roughly about 80kbps - 90kbps for each up and down link. You can use codecs with higher compression, such as iLBC or GSM to increase the number of concurrent calls on an existing line. However, your IP PBX / VOIP hardware MUST support these codecs. Beware, more compression means lower call quality.
If you want more concurrent calls while reserving call quality, we recommend you install a fibre or UNS Internet Connection, or an additional (dedicated) ADSL connection on your site to increase reliability.