SIP Trunks for Operators Who
Dial Like They Mean It.

A SIP trunk is a virtual phone line that connects your phone system (PBX, dialer, contact center) to the public telephone network over the internet using the SIP protocol. Instead of physical copper lines, your calls travel as data packets. The trunk is the connection between your system and the carrier — in this case, SIPNEX.

On SIPNEX, there is no artificial concurrent channel limit at the trunk level. Your capacity is determined by your own server resources and internet bandwidth, not by a cap we impose. Most resellers limit you to 10–50 concurrent channels per trunk — we don't.

G.711 (ulaw/alaw) for highest quality, G.729 for bandwidth-constrained environments, and Opus where supported. For VICIdial deployments, we recommend G.711u as the primary codec with G.729 as a fallback.

You need an IP-capable PBX, dialer, or softswitch with a reliable internet connection. VICIdial, FreePBX, Asterisk, FreeSwitch, 3CX, and most modern platforms support SIP trunking natively. We provide configuration templates for VICIdial and will assist with other platforms.

24 hours from signed agreement to live trunk, typically. We provision your initial DIDs and trunk credentials within one business day. Number porting from another carrier takes longer (7–14 business days is standard) but you can start dialing on new DIDs immediately while the port completes.

STIR/SHAKEN is a caller ID authentication framework mandated by the FCC. Your outbound calls are cryptographically signed by the originating carrier with an attestation level (A, B, or C). A-level means verified caller — best answer rates. SIPNEX signs with our own SP-KI certificate, giving you direct A-level attestation. Most resellers can only provide B-level because they don't hold their own certificate.

Yes. We support full number portability for local, toll-free, and vanity numbers across North America. The porting process typically takes 7–14 business days depending on the losing carrier. You can start dialing on new SIPNEX-provisioned DIDs immediately while porting completes in the background.

Phone and email support from engineers who run VICIdial and high-volume dialing operations themselves. When you call us about a sip.conf issue, the person answering knows what that means without escalation. We don't have a generic tier-1 helpdesk — your first contact is the person who can fix it.