How Beside Replaced Twilio, Vonage, and ElevenLabs with One AI-Native Platform

Beside makes AI receptionists for small businesses. An auto detailer misses a call while working in the bay; Beside's agent picks up, quotes the ceramic package, books the appointment, and follows up the next day. A real estate agent is out showing a house; Beside captures the listing inquiry, schedules the showing, and sends comps automatically. The product handles the entire phone workflow, from the first ring to the completed task, so the business never has to staff a desk just to answer calls.

The business model depends on volume. Every call has to connect, sound natural, and complete a task. When the AI pauses too long or the audio stutters, the caller hangs up and the business loses the lead. In this market, latency is revenue.

When three vendors can't get a call through

Beside's original architecture stitched together Twilio for call control, Vonage for SIP trunking and phone numbers, and ElevenLabs for text-to-speech. Three vendors, three contracts, three APIs, and three places for latency to accumulate.

The Frankenstack pattern played out exactly as it does for every team that stitches voice AI together from components. Each vendor in the chain adds a network hop and a processing delay. By the time a caller's speech was transcribed, sent to the AI, routed to ElevenLabs for synthesis, sent back through Vonage's SIP trunk, and delivered through Twilio's call control, round-trip latency pushed toward 1200ms. Callers heard dead air. Conversations felt robotic and halting. For a product whose entire value proposition is answering the phone faster than a human, the architecture was working against the product.

Debugging was the other casualty. A dropped call meant checking Twilio's logs, then Vonage's, then ElevenLabs', then trying to correlate timestamps across all three systems. When DTMF verification failed or call control bugs appeared, there was no single place to look. Each vendor pointed at the others. Not maliciously. Structurally. Nobody owned the full call path, so nobody could fix it.

Twilio was also pushing for a $500K commitment. Beside needed quality improvements and better margins, not a bigger contract with the same broken architecture. The old stack was too expensive to keep and too fragmented to fix.

One network, from the first ring to the AI response

Beside consolidated on Telnyx as its single voice and AI platform, displacing Twilio, Vonage, and ElevenLabs entirely. The migration started with TeXML as a drop-in replacement for Twilio's TwiML, so existing call flows ported over without rewriting application logic. Where TeXML's declarative model reached its limits, Beside layered in the Call Control API for programmatic call handling, DTMF processing, and dynamic routing. Phone numbers ported from Twilio and Vonage to Telnyx.

The latency improvement came from architecture, not optimization. Instead of routing audio through a third-party TTS provider and back, Beside uses Telnyx Voice AI Agents with built-in speech synthesis on the same network that carries the call. The network that answers the phone also runs the inference. The network that carries the SIP trunk also generates the speech. Co-locating those functions on one carrier-owned network eliminated the inter-vendor hops, and latency dropped accordingly. Where the Frankenstack pushed round-trips toward 1200ms, the single-stack approach brought natural, responsive conversations.

A Telnyx solutions engineer worked directly with Beside through the migration, debugging WebRTC authentication issues, resolving call control edge cases, and navigating API behavior discrepancies. Credit limit increases were processed quickly as usage scaled. One escalation path instead of three vendors pointing at each other.

Building faster on a single stack

Three vendors became one contract, one invoice, one support channel, and one data boundary. The integrated stack also accelerated development. Issues that used to require coordinating across three vendor support teams now have a single escalation path on Telnyx's own network.

Beside is expanding its AI receptionist into more verticals and more complex call flows. With voice, telephony, and AI on one platform, they can add capabilities without rearchitecting. More businesses to serve, more calls to handle, and the infrastructure that already works at the scale they need.

Beside is building the future of SMB phone support. Telnyx supplies the infrastructure.