The telephony layer your AI voice agent needs
Ultra-low-latency SIP trunking, instant number provisioning, and STIR/SHAKEN attestation — purpose-built for Vapi, Retell, Bland.ai, and OpenAI voice agents.
Key benefits
Sub-50ms media latency
Purpose-built media infrastructure delivers audio with under 50ms latency — essential for natural-sounding AI conversations.
WebSocket SIP
Connect your AI agent over WebSocket-based SIP, eliminating NAT traversal headaches and firewall complexity.
STIR/SHAKEN attestation
Full A, B, and C attestation ensures your AI agent calls pass carrier verification and reach end-users reliably.
Instant provisioning
Provision DID numbers in under a second via API. Scale from one number to thousands without manual intervention.
1000+ concurrent channels
Handle massive call volumes with elastic channel capacity. No pre-booking, no capacity planning required.
Global PSTN
Reach any phone number in 60+ countries. Your AI agent can call or receive calls from anywhere in the world.
How it works
Configure SIP trunk
Point your AI agent platform (Vapi, Retell, Bland.ai, OpenAI) at your CloudVNO SIP termination URI. No hardware required.
Provision DID numbers
Instantly provision local or toll-free numbers via API. Assign them to your trunk and start receiving inbound calls.
Connect your AI agent
Your agent handles the conversation over low-latency media. CloudVNO manages PSTN connectivity, STIR/SHAKEN, and call routing.
Code example
from cloudvno import Client
client = Client("YOUR_API_KEY")
# Provision a DID for your AI agent
number = client.numbers.provision(
country="US",
capabilities=["voice"],
ai_optimized=True,
)
# Configure SIP trunk for your agent
trunk = client.sip.trunks.create(
name="vapi-agent-trunk",
termination_uri="sip:your-agent.vapi.ai",
origination_uri="sip:us1.cloudvno.com",
numbers=[number.phone_number],
)
print(f"DID: {number.phone_number}")
print(f"Trunk SID: {trunk.sid}")
print(f"WebSocket URI: {trunk.websocket_uri}")Features
Pricing
See full pricing →Pay as you go. No minimums. No contracts. Volume discounts available.
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