Can I use SIP if my PBX is behind a NAT firewall?

Yes, using SIP registration, this is possible.

Do I need a specific type of VOIP phone system?

Different SIP providers are certified to work with various IP phone system manufactures. Some IP phone system manufactures require additional equipment to operate. Check with an Access Technologies representative to determine if your phone system is certified.

Note: It is important that you test your phone system EXTENSIVELY with the SIP provider before implementing production systems with SIP. Often, demo trunks can be ordered on a monthly basis for this purpose. Test all important features like call forwarding, conferencing, transferring, etc. Often a phone system can be “certified” but certain features can be missing. As an agent, we’ll try to get you in touch with another agent who is using the same type of phone system for technical / feature discussions.

What fail-over options do I have with SIP?

The answer depends on the SIP provider. We’ll answer this question with Broadvox capabilities:

• The ability to provide a primary / secondary configuration to two SIP trunks.
• The ability to load balance to multiple IP addresses on the customer’s end. Concurrent call sessions (per trunk) must be split between IP addresses.
• The ability to perform fail-over to a POTS line or cellular number if the SIP trunk goes down.
• The ability to automatically fail over between separate Internet connections using SIP registration.

Note: Fail-over capabilities also depend on the phone system and/or network equipment deployed. We’ve seen in work natively with some phone systems and we’ve seen additional routers that had to be installed with others. We highly recommend you test all SIP capabilities, including fail-over, with your particular brand of PBX.

I don’t want to pay for a trunk I might not use. Can I only pay for minutes used?

Absolutely. With Broadvox’s GoDomestic product, you only pay for the minutes used, not on a per-trunk basis. You can have as many simultaneous call sessions as your bandwidth can handle. This is very popular for outbound call centers and schools who don’t use their phone lines during parts of the year.

Do I need a static IP address to support SIP trunks?

No, with Broadvox, SIP trunks can be provisioned with a dynamic IP address using registration.