What to evaluate
SIP trunk flexibility, per-minute inbound/outbound rates, geographic DID coverage, concurrency limits, media server region proximity to your AI runtime, and support responsiveness for production incidents.
Resource — Carriers
Choosing a voice carrier for AI voice agent deployments.
The carrier you choose affects per-minute cost, geographic coverage, SIP flexibility, concurrency headroom, and the latency profile of every call. The right choice depends on your volume, geography, and how much control you want over the SIP layer. Telepath works with all of them.
What AI voice adds
AI voice deployments run at sustained high concurrency, care more about media latency than traditional call centers, and need carriers that support direct SIP trunking rather than proprietary media relay paths.
Telepath is carrier-neutral
Telepath doesn’t prefer any carrier. It accepts standard SIP/RTP from any provider. Use whichever carrier fits your volume and geography, and switch or add carriers without changing your AI agent configuration.
Carrier context for AI voice teams
This is a neutral overview based on what teams building AI voice at scale typically encounter with each carrier. Pricing and feature availability change; verify directly with each carrier for current terms. All of the carriers below can be used with Telepath via a standard SIP trunk configuration.
Twilio
Twilio is the most widely deployed carrier in AI voice because it has the largest developer ecosystem, the best documentation, and the most familiar API surface. Elastic SIP Trunking gives you a direct SIP trunk with configurable concurrent call limits. Twilio’s media servers are distributed globally, though call routing to a specific media server is not user-configurable. Per-minute rates are higher than most other carriers, which matters at volume. Twilio’s SIP implementation is well-tested and handles re-INVITEs and edge cases reliably. For teams prioritizing developer experience and operational familiarity, Twilio is a reasonable default. For teams optimizing unit economics at 10,000+ minutes per day, the rate differential relative to Telnyx or Bandwidth is worth evaluating.
Telnyx
Telnyx has strong pricing for high-volume deployments and good SIP flexibility. Their elastic SIP trunking supports high concurrency without pre-provisioned trunk groups, which simplifies scaling. Telnyx operates their own global IP network rather than routing through third-party transit, which gives them more control over media path quality and latency. Their developer portal and API are solid, and their support response for production issues is generally responsive. Telnyx is often the carrier that teams migrate to when Twilio unit economics become the primary constraint at volume.
Bandwidth
Bandwidth is an enterprise-grade carrier with particularly strong US coverage and direct PSTN access. They operate their own US network infrastructure (not just a CPaaS layer on top of a larger carrier), which gives them a degree of control over call quality and routing that pure CPaaS providers lack. Bandwidth’s onboarding process is more involved than Twilio or Telnyx, and they typically target enterprise accounts rather than self-serve developers. For teams with large US call volumes, local number compliance requirements, or enterprise procurement processes, Bandwidth is worth evaluating seriously. Their SIP trunk implementation is production-grade and widely deployed at enterprise scale.
Vonage (now part of Ericsson)
Vonage has a strong position in European markets and EMEA origination. For AI voice deployments targeting European callers, Vonage’s geographic coverage and local presence in key markets can matter. Their SIP API and developer portal have improved over recent years. Teams primarily serving US callers will find Twilio or Telnyx more straightforward, but Vonage is worth considering if significant EU call volume is part of the deployment.
Plivo
Plivo is a competitive option for cost-sensitive deployments with straightforward requirements. Their pricing is consistently lower than Twilio for comparable call volumes, and their API is reasonably well-documented. Coverage is solid for US and India, with more limited coverage in other markets. Teams with high inbound volume from those geographies and price sensitivity as a primary constraint find Plivo a viable option. Their SIP implementation is standard and works reliably with Telepath.
SignalWire
SignalWire is built on FreeSWITCH, which gives it deep SIP flexibility and a strong appeal to technically oriented teams who want fine-grained control over their telephony stack. SignalWire supports native SIP trunking, custom SIP headers, and advanced media handling options that more consumer-oriented CPaaS providers don’t expose. For teams that are comfortable with SIP internals and want maximum configurability, SignalWire is worth evaluating. Their pricing is competitive, and the FreeSWITCH heritage means SIP behavior is standards-compliant and highly configurable.
Sinch and Flowroute
Sinch has global scale and strong messaging roots in addition to voice. Their voice SIP trunking is suitable for AI voice deployments, particularly for teams that also need messaging capabilities on the same carrier account. Flowroute (acquired by Intrado/West) is another solid SIP provider with US focus, competitive pricing, and good SIP flexibility. Both work with Telepath via standard SIP trunk configuration.
Start with any carrier
Telepath connects via SIP trunk to all major carriers. Start with the carrier you already have, and switch or add carriers later without changing your AI agent configuration.
Compare them with data
Because Telepath sits between your carrier and your agent, per-call metrics are comparable across carriers on a consistent measurement basis. Carrier quality comparisons are evidence-based.
Add carriers without re-plumbing
Multi-carrier failover and load distribution are configurable at the carrier SIP routing layer. Adding a second carrier to your Telepath connection doesn’t require changes to your AI agent setup.
Bring whichever carrier fits your deployment. Telepath handles the rest.
Telepath connects your SIP carrier to your AI voice agent with a clean transport layer and per-call diagnostics that let you see exactly how each carrier is performing.