There is no single best SIP trunk for a VICIdial® or AI-voice-bot floor. The right one passes seven checks: it allows dialer and AI traffic in writing, gives you enough calls per second and channels, bills in increments that suit short calls, handles caller ID and STIR/SHAKEN, tolerates your short-call mix, and answers traceback requests. VoiceOI does not sell trunks or endorse a carrier; any SIP carrier works through the Carrier Manager.
Last reviewed by the VoiceOI team
No SIP trunk is best for every floor, and a carrier's own comparison page will not be neutral about it. Use the seven checks below, and get each answer in writing before you move traffic.
VoiceOI does not sell SIP trunks, phone numbers or minutes, and it does not recommend a carrier. Any SIP carrier works once its sip.conf or pjsip.conf block is pasted into the Carrier Manager. Twilio and Telnyx are ordinary SIP trunks from that point of view.
The facts below come from each carrier's and regulator's own pages, read on October 1, 2026. Limits and prices change, so confirm them with the carrier before you buy.
What to confirm with a carrier, and what should make you pause.
| Check | What to confirm | Red flag |
|---|---|---|
| 1. Dialer and AI traffic is allowed | The acceptable-use policy covers outbound auto-dialed and AI-voice traffic, in writing. | Dialing is listed as improper use, or support will not confirm in writing. |
| 2. Calls per second (CPS) | Your CPS limit, how to raise it and what happens to attempts over it. | A default far below your launch rate, or surcharges for peaks you did not plan for. |
| 3. Concurrent channels | The channels you get on day one, not after a later verification step. | A low default cap that blocks the bots you plan to run. |
| 4. Billing increments | Per-second, 6/6 or 60/60, and any minimum charge per call. | 60-second rounding on a floor whose calls often end in a few seconds. |
| 5. Caller ID and STIR/SHAKEN | Who attests your numbers, at what level, and the caller ID rules. | B or C attestation on numbers you want to display, or no rules you can read. |
| 6. Short and unanswered calls | The carrier's thresholds, and what happens when you pass them. | A policy that does not support short calls, when answering machine detection ends calls early. |
| 7. Traceback and listing | A named contact for traceback requests and a Robocall Mitigation Database listing. | No contact, no listing, or no answer to either question. |
Each check has the carrier or regulator wording behind it, so you can verify it yourself.
In VoiceOI you add the carrier in the Carrier Manager by pasting the sip.conf or pjsip.conf block your carrier gives you. The manager reloads on save, and bots dial through it. The setup guides are the Twilio SIP trunk guide, the Telnyx SIP trunk guide and the SIP trunk guide for any carrier.
If you run VICIdial, carriers are set up in VICIdial's own admin, and bots join your campaigns as remote agents (VICIdial AI integration). Either way, the trunk carries dialing, answering machine detection and transfers. Your carrier bills the minutes, and VoiceOI bills per bot with no per-minute AI fee.
Copy these into an email to sales or support, and keep the answers.
None of these proves a carrier is wrong for you. Each is a reason to ask more questions first.
Every quotation and figure above comes from one of these pages. Links to commercial vendors that compete with carriers or with us are marked nofollow.
Short answers on picking a carrier for a dialer or AI voice bot floor.
There is no single best carrier, and a carrier's own comparison page will not be neutral about it. Use the seven checks on this page: written permission for dialer and AI traffic, CPS, channels, billing increments, caller ID and attestation, short-call tolerance, and traceback. VoiceOI does not sell trunks and does not recommend a carrier.
Yes, as ordinary SIP trunks: paste the carrier's sip.conf or pjsip.conf block into the Carrier Manager and bots dial through it. Read each carrier's acceptable-use and voice policies first, because they treat dialer traffic and short calls differently. VoiceOI does not require or endorse any particular carrier.
Plivo's documentation gives a rule of thumb: divide your peak concurrent calls by your average call duration in seconds. For example, 100 bots on calls that average 30 seconds need about 3.3 calls per second, and the need rises if many calls end within a few seconds on answering machines. Compare the result with the carrier's default CPS limit.
No. Attestation says how confident the originating provider is about who is calling and whether they may use the number. Labels come from analytics apps and networks. TransNexus reported that in March 2026, 89.8% of the calls authenticated by prolific robocall signers had an A-level attestation.
They can. At a 60/60 increment an 8-second call is billed as 60 seconds, at 6/6 as 12 seconds and at 1/1 as 8 seconds. Some carriers also limit the share of very short calls. Model your cost on your own mix of machine and human answers.
No. You bring your own carrier. VoiceOI bills prepaid per bot with no per-minute AI fee, and your carrier bills the minutes. Any SIP carrier works once its configuration block is added to the Carrier Manager.