Managed Agents at Previously $0.06 $0.03/minManaged Agents are Previously $0.06 $0.03/min.
SIP trunk

Plivo AI voice agents over a Zentrunk SIP trunk

Point a Plivo Zentrunk inbound trunk at sip.cartesia.ai, link the trunk and assign an agent, and you keep your Plivo numbers and rates.

Start buildingRead the docs
create-provider.sh
curl -X POST "https://api.cartesia.ai/agents/phone-numbers/providers" \
  -H "X-API-Key: $CARTESIA_API_KEY" \
  -H "Cartesia-Version: 2026-08-14" \
  -H "Content-Type: application/json" \
  -d '{
    "type": "sip_trunk",
    "label": "Plivo",
    "inbound": {
      "credentials": { "username": "YOUR_URI_USERNAME", "password": "YOUR_URI_PASSWORD" },
      "media_encryption": "allowed"
    },
    "outbound": {
      "address": "YOUR_TRUNK_ID.zt.plivo.com",
      "transport": "tcp",
      "destination_country": "US",
      "credentials": { "username": "YOUR_ZENTRUNK_USERNAME", "password": "YOUR_ZENTRUNK_PASSWORD" }
    }
  }'

Cartesia docs: SIP trunking

What a Plivo AI voice agent can do

What teams build when they put Cartesia and Plivo together.

Your numbers and rates

Cartesia charges only agent calling rates on a SIP trunk number, and Plivo bills its own rates for the line.

Two-way calling

Inbound calls reach the agent assigned to the dialed number. Outbound calls go through your Zentrunk outbound trunk.

Transfers

The agent transfers calls by SIP REFER to a phone number or a SIP URI, as long as Plivo accepts the REFER.

Plivo settings

Inbound trunk direction
inbound
Origination URI
sip.cartesia.ai;transport=tcp
Origination URI authentication
On, with a username and password that you also enter as Cartesia inbound credentials.
Outbound trunk authentication
A Zentrunk credential. Plivo also accepts an IP access control list.
Outbound address in Cartesia
The outbound trunk's domain, in the form <trunk_id>.zt.plivo.com.
Secure trunking
Plivo's secure setting turns on TLS signaling and SRTP media. Set Cartesia to TLS and required media encryption to match.

Set it up

A SIP trunk, with no native Plivo integration. A Zentrunk inbound trunk points at sip.cartesia.ai, and Cartesia calls out through an outbound trunk. Vendor details read in November 2026.

  1. Create an origination URI at Plivo

    In Zentrunk, create an origination URI of sip.cartesia.ai;transport=tcp. Turn on authentication and set a username and password, so Plivo signs in when it sends a call.

  2. Create an inbound trunk and attach your numbers

    Create a Zentrunk trunk with the inbound direction and the URI as its primary URI. Then set each Plivo number to use that trunk.

  3. Create an outbound trunk

    Create a Zentrunk credential, then an outbound trunk that uses it. Copy the trunk domain, which looks like 21784177241578.zt.plivo.com.

  4. Link the trunk in Cartesia

    Create a provider with the origination URI's username and password as inbound credentials, the trunk domain and Zentrunk credential as outbound settings, then import each number and assign an agent.

Documentation

Before you build

Only inbound trunks attach to numbers

Plivo lists only inbound trunks in a number's configuration. The outbound trunk carries Cartesia's calls out and is not attached to a number.

Test a transfer early

Transfers go out as SIP REFER. Place a test transfer before launch to confirm Plivo accepts it for your destination type.

Use cases for teams on Plivo

Customer support

Resolve support calls on the first try, refund and credit within your rules, and keep customers who call to cancel.

See the use case

Appointment scheduling

Book, reschedule and confirm appointments on your calendar, 24/7.

See the use case

More integrations

All integrations
SIP trunk

Vonage

Run a Cartesia voice agent on Vonage numbers with Vonage SIP Trunking, at your Vonage rates.

  • Managed Agents
See the integration
SIP trunk

SIP trunking

Point your carrier at sip.cartesia.ai and run Cartesia voice agents on your own numbers, with TLS, SRTP and digest or IP access control.

  • Managed Agents
See the integration
Official

Twilio

Connect your Twilio account to bring your existing phone numbers, including international ones, to Cartesia voice agents.

  • Managed Agents
See the integration

Enterprise-grade security

  • HIPAA compliant badge

    HIPAA compliant

  • SOC 2 Type 2 badge

    SOC 2 Type 2

  • GDPR badge

    GDPR

Plivo AI voice agent FAQs

How do I connect Plivo to an AI voice agent?

Over a Zentrunk SIP trunk. Create an origination URI of sip.cartesia.ai;transport=tcp with authentication on, attach it to an inbound trunk, and point your Plivo numbers at that trunk. Then link the trunk in Cartesia, import each number and assign an agent. There is no native Plivo integration.

Why does Plivo need two trunks?

Plivo lists only inbound trunks in a number's configuration, so one inbound trunk sends your numbers' calls to Cartesia. A separate outbound trunk, with a Zentrunk credential, carries the calls Cartesia places. Its domain looks like 21784177241578.zt.plivo.com and goes in Cartesia as the outbound address.

Can I encrypt calls between Plivo and Cartesia?

Yes. Plivo's secure trunking setting turns on TLS signaling and SRTP media. Set Cartesia's transport to TLS and media encryption to required to match. Choosing those in Cartesia alone does not turn on SRTP at Plivo.

Can the agent transfer Plivo calls to a person?

Yes, as a cold transfer by SIP REFER to a phone number or a SIP URI, as long as Plivo accepts the REFER for that destination. Place a test transfer before launch. If the carrier rejects it, Cartesia keeps the caller connected.

What does a Plivo number cost on Cartesia?

Plivo bills the line at your Plivo rates, and Cartesia adds no telephony fee on a trunk number. Agents run at $0.03/min, plus LLM usage. Numbers that Cartesia provisions, which are US only, carry a $0.014 per minute telephony fee instead.

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