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Single line adapter Dual line adapter
8-line adapter 4-line adapter

16-48 line adapter


VoIP for Legacy PBX

If you are satisfied with the performance and features of your current PBX connected to traditional telephone lines, you can reap the savings of VoIP by simply using an Analog Telephone Adapter (ATA) device like the ones pictured on the left in conjunction with any of our SIP Trunk plans and starting at as little as $2.75 per month. You can retain your current phone numbers and add more anytime including numbers in other cities or even other countries.

This solution is ideal for businesses of any size that need the assurance of having as many lines as needed but would only like to pay only for the actual service that they use. SigmaVoIP can ship the adapter as a do it yourself install kit or have a technician install it onsite on most traditional PBX telephone systems or single and multi-line traditional phones. The savings are phenomenal with most customers saving up to 80% and much more on International calling.

The only requirement to use this solution is having a reliable internet connection. The speed required is based on the number of concurrent calls (lines in use at once), please see the table below for speed requirements.

Lines Minimum Optimal
1 32.7Kbps 80Kbps
2 65.5Kbps 160Kbps
4 131Kbps 320Kbps
8 262Kbps 640Kbps
16 525.1Kbps 1280Kbps
24 786.2Kbps 1920Kbps
36 1179.3Kbps 2880Kbps
48 1572.4Kbps 3840Kbps
VoIP PRI 754Kbps 1840Kbps
Note: 1Mbps = 976.56Kbps

SigmaVoIP uses exclusively Award winning Grandstream devices to offer this service to ensure reliable performance and expert and swift support.

For a complimentary consultation and customized price quote using this solution, please fill out the form below or call us at 1-888-283-9810.

How many lines Max. 48
Will you self-install? Yes    No




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Serving all major  metro areas in Connecticut, New York, New Jersey, Massachusetts, DC, Texas, California, Virginia, Rhode Island, Florida, Virginia and Colorado         Copyright 2014 SigmaVoIP, LLC.