Your predictive dialer is only as good as the trunk feeding it.
Channel caps throttle your algorithm. B-level attestation kills your answer rate. High PDD breaks your pacing. SIPNEX SIP trunking removes all three — unlimited channels, A-level attestation, sub-3s PDD. Built by operators who run predictive dialers.
What a predictive dialer demands from its carrier.
A predictive dialer places many calls at once and predicts when agents will free up. It only works if the trunk under it keeps pace. The dialer needs three things from a carrier: channels that never cap, call setup that never drifts, and caller ID the networks trust.
Miss any one and the math on top falls apart. This page covers the carrier side — what the trunk must deliver, and how SIPNEX delivers it. New to the software itself? Start with what a predictive dialer is and how pacing works, then come back for the trunk.
Unlimited Concurrent Channels
No caps. No per-channel fees. Your dialer's algorithm runs without carrier-imposed throttling. 200 channels or 2,000 — same trunk, same price per minute.
A-Level STIR/SHAKEN
Every call signed with our own SP-KI certificate at A-level. Not B-level inherited from an upstream carrier. The single highest-impact factor for answer rates.
Sub-3-Second PDD
Consistent post-dial delay under 3 seconds. Low variance. Your predictive algorithm's pacing predictions work because the underlying timing is stable.
G.711 Native — No Transcoding
G.711u pass-through without carrier-side transcoding. Clean audio for AMD accuracy and agent conversation quality. No compression artifacts.
Dialer-Specific Support
Support engineers who run VICIdial. They know sip.conf, AMD tuning, adaptive pacing, and CID rotation strategy. First-call resolution on dialer-specific issues.
Wholesale Pricing
Carrier-direct rates published on our website. No CPaaS markup. No per-channel fees. No platform overhead. Just minutes and DIDs.
What predictive dialing demands from the carrier.
A predictive dialer exists to dial multiple lines per agent instead of leaving agents manually dialing one lead at a time. The predictive dialing software watches call metrics — answer rate, average talk time, abandon rate — and adjusts its pacing in real time. Every one of those predictions assumes the layer below behaves: consistent call setup, honest signaling for busy signals and no-answers, and enough capacity to absorb the next burst.
When a human answers, milliseconds matter. The carrier has to hand the live call back fast enough for the dialer to connect answered calls to agents before the person says a second hello. That handoff window decides customer experiences — dead air is why so many answered calls end before the agent speaks. It compounds from both sides: pacing and AMD settings on the dialer, answer-signaling delay on the trunk. The trunk side is ours to keep tight.
Caller ID reputation compounds the problem. Auto dialers burn through phone numbers quickly once analytics engines flag them, and outbound dialers running on B-level attestation get flagged faster. SIPNEX signs with its own STIR/SHAKEN certificate, so calls from the phone numbers we assign carry full A-level attestation — the carrier attesting that it knows the caller and the caller's right to use the number.
None of this depends on where the dialer runs. Whether your outbound call center is a cloud-based VICIdial cluster or racked hardware in your own facility, the trunk requirements are identical — and they are different from what office phone systems need. Sales teams measure the difference in conversations per hour, not in feature checklists.
The compliance layer: TCPA and calling hours.
The Telephone Consumer Protection Act shapes every US predictive campaign: abandonment limits, consent rules, and calling windows tied to the lead's local time zone. Those controls live in your dialer configuration, and the legal obligations stay with you as the caller. The carrier's contribution is the infrastructure underneath — A-level signing on every call and clean number provisioning — so a compliant campaign is not undermined at the network layer. Our guide to auto dialer laws in 2026 covers the rules in detail.
How pacing math meets the trunk.
The pacing algorithm watches two numbers: answer rate and agent availability. It dials ahead of demand. If one call in four gets answered, it launches about four calls per agent about to free up. The ratio adjusts every few seconds as the numbers move.
That math rests on two assumptions about the carrier. Call setup time stays stable, so the dialer knows when a dialed call will connect. And channels never cap, so the dialer can launch every call the ratio calls for.
When the carrier varies, the predictions miss. The dialer over-dials on some cycles and under-dials on others. Calls connect with no agent free, and each one counts as an abandon. The FCC abandoned-call rate rules cap abandons at 3 percent of answered calls.
Predictive vs progressive, preview, and power dialers.
| PREDICTIVE | PROGRESSIVE | PREVIEW | POWER | |
|---|---|---|---|---|
| How it dials | Many lines per agent, algorithm-paced | One call per available agent | Agent reviews lead, then dials | Fixed ratio, no pacing predictions |
| Agent idle time | Lowest | Low | Highest | Low to moderate |
| Abandon-rate risk | Highest — pacing must be tuned | Minimal | None | High at aggressive ratios |
| Trunk load | Heavy, bursty | Steady, moderate | Light | Heavy, steady |
| Best for | Large lists, short calls | Compliance-sensitive campaigns | High-value, researched calls | Small teams, simple lists |
Weighing the two auto-paced modes against each other? Read the full predictive vs progressive dialer comparison.
Predictive dialer trunk: SIPNEX vs typical provider.
| SIPNEX | TYPICAL PROVIDER | |
|---|---|---|
| Concurrent channels | Unlimited, no fee | Capped at 10–100 |
| STIR/SHAKEN attestation | A-level (own cert) | B-level (upstream) |
| Post-dial delay | Under 3 seconds | 3–8 seconds variable |
| Per-channel fee | None | Charged monthly per channel |
| Codec | G.711 native pass-through | May transcode to G.729 |
| Billing increment | 12/6 (6-sec steps) | Often 60/60 full minutes |
| Dialer-specific support | VICIdial engineers | Generic SIP support |
| Contract required | No | Often 12+ months |
Current per-minute rates are on the published volume-tier pricing page. No quote gate.
Predictive dialer carrier FAQs.
What happens if I run a predictive dialer on a generic carrier?
How many concurrent channels do I need for predictive dialing?
Does STIR/SHAKEN attestation affect my dialer's answer rate?
What dial ratio should I start with on a new trunk?
What codec should I use for predictive dialing?
What PDD should I expect?
How does PDD affect the 3 percent abandon rate limit?
Do you support VICIdial specifically?
What does a predictive dialer trunk cost to run?
Can I test before committing?
Go live in 3 steps.
- Request a trunk. Provisioned in 24 hours. No contract, no minimum term.
- Point your dialer at the SIPNEX SIP proxy. Run a split campaign next to your current carrier.
- Compare answer rate, PDD, and audio on the same leads. Port when the numbers win.
Test us against your current carrier.
24-hour setup. No commitment. Compare answer rates on the same leads.