What is SIP trunking?

SIP trunking replaces traditional phone lines with an internet-based connection between your PBX or UC platform and the public telephone network, delivering voice calls at lower cost and with greater flexibility.

Does Softtop SIP trunking support E911?

Yes. Softtop SIP trunks include Enhanced 911 support. Emergency call routing is configured per-location so first responders receive the correct registered address for every user.

How many concurrent calls can I run?

SIP trunk capacity scales elastically. You define a minimum channel count and a burst limit. Additional channels activate automatically during peak demand without pre-purchasing capacity in advance.

Is STIR/SHAKEN attestation included?

Yes. All Softtop SIP trunks are STIR/SHAKEN attested at the carrier level, ensuring your caller ID is verified and your calls are not flagged as spam by receiving carriers.

Can I connect my existing PBX?

Yes. Softtop SIP trunks connect to any SIP-compatible PBX — on-premise Cisco, Avaya, Asterisk, FreePBX, or cloud systems — so you can upgrade connectivity without replacing your phone infrastructure.

What is elastic channel scaling?

Elastic scaling means your SIP trunk expands and contracts with call volume automatically. You are not locked into a fixed channel count — capacity adjusts in real time and billing reflects actual usage.

SIP Trunking for US Business — Tier-1 Direct Interconnects