Business VoIP

What is a SIP Service?

A SIP service connects a company’s PBX (internal) telephone system to the traditional telephone network.

SIP services that connect to the Comvergence network may be used with VoIP equipment such as ATAs*, IP handsets, Softphones, Mobile Phones with VoIP capability and Gateways or for connection to compatible IP PBXs such as Switchvox, Cisco Call Manager or Asterisk to make/receive calls over VoIP.

*An ATA is an Analogue Terminal Adapter that connects an Analogue Telephone to a VoIP network

All SIP Trunk Services support the following:

  • Caller ID (CLI) and caller ID restriction at no additional charge
  • Advanced call forward, call diversion and follow-me functions (web interface)
  • Call Waiting, Hold and Transfer
  • Line Hunting at no additional charge
  • Voicemail, including Voicemail to Email
  • Fallover Support (should your VoIP Service go down, calls to your number can be sent automatically to your Mobile or other nominated number)
  • Support for G729a and G711A voice codecs
  • Direct Indial Support for IP PBXs

Initial and Monthly Costs
ServiceInitial SetupMonthly Cost
SIP Trunk * 10
Includes 10 SIP Trunks (10 Direct Indial Numbers and 10 Concurrent Calls)
Additional SIP Trunks and direct indial numbers. (min requirement 10)$5.50$5.50
100 Number In dial Range Hosting Fee$30.00$30.00
Initial SIP Trunk purchased in block of 10 SIP Trunks and then additional SIP trunks can be added to the same trunk.
Each SIP trunk allows for one concurrent call and includes one direct indial number. These SIP trunks can be attached to your onsite PBX.

How does it work?

The VoIP service is setup on your PBX or VoIP equipment and connects back to the Comvergence voice network via the Internet or a dedicated Voice circuit from Comvergence. All inbound and outbound calls from your PBX are then sent via VoIP.

Service numbers for each line are allocated in the calling area of the service address.
These numbers can be used as Direct Indial Numbers direct to an Extension on a PBX (where supported).


The service is available nationally.


For business-grade delivery, it is highly recommended that you obtain a Multiline Service from Comvergence, a dedicated link for Voice Traffic only.

If you wish to use the Business VoIP Service over your existing internet connection, note there are no QoS or rate limiting controls on your connection to prioritise VoIP traffic. You may therefore experience quality issues such as call breakup.

You may also experience issues if your ISP or the bandwidth between their network and the Comvergence Network is congested. Generally with the G729a Voice Codec, each line that is in use will require 40kbps of bandwidth.

Further Information

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