Before an AI voice agent can pick up a single call, you have to decide how it reaches the phone network. There are two clean ways to do it: bring your own SIP trunk (BYOC) or connect a provider account like Twilio, Exotel, or Plivo. Both handle inbound and outbound calling. The difference is who owns the carrier relationship, who bills you, and how much setup you sign up for.
Most guides make this sound like a religious choice. It is not. It is a practical one that hinges on whether you already have a trunk, whether you care about your existing numbers and rates, and how fast you want to be live. This post lays out the trade-off honestly, with a comparison table, so you can pick in a few minutes.
Already own a SIP trunk? BYOC lets you keep your carrier, numbers, and negotiated rates and add AI on top. See Bring Your Own SIP Trunk — or read on to compare it against a provider account first.
Quick verdict (TL;DR)
| If this is you... | Choose |
|---|---|
| You already have a SIP trunk and negotiated rates | Bring your own SIP trunk (BYOC) |
| You want numbers and calling live today, no trunk of your own | Provider integration (Twilio/Exotel/Plivo) |
| You must keep existing DIDs printed on invoices and directories | Bring your own SIP trunk (BYOC) |
| You have no telephony yet and no carrier relationship | Provider integration |
| You run high volume and want to pay the carrier directly | Bring your own SIP trunk (BYOC) |
Short version: if you already have a trunk, bring it. If you do not, a provider account gets you calling fastest.
The two options, defined
Bring your own SIP trunk (BYOC). You connect a SIP trunk you already own from any carrier you like. The connection is provider-agnostic and standards-based: you configure the SIP host, port, transport, and authentication, and any standards-compliant trunk works, including your Twilio, Telnyx, Tata, or Airtel trunk. You keep the carrier relationship, you pay the carrier directly, and you keep your numbers. Calls terminate on Edesy's managed SIP infrastructure through the Edesy Voice API; you manage the trunk and the platform runs the media path and the AI agent.
Provider integration. Instead of your own trunk, you connect a provider account, such as Twilio, Exotel, or Plivo. You provision numbers through that provider, and the provider bills you for telephony. There is no trunk of your own to configure, no gateways to define, and no SIP IP to whitelist. You connect the account and go. See Telephony Providers for the details.
Both options do inbound and outbound. Neither is a downgrade — they suit different starting points.
Head-to-head comparison
| Dimension | Bring Your Own SIP Trunk (BYOC) | Provider Integration (Twilio/Exotel/Plivo) |
|---|---|---|
| Carrier | Your existing SIP carrier | The provider's network (Twilio/Exotel/Plivo) |
| Control | Full control over the trunk, transport, and auth | Provider manages the carrier layer for you |
| Billing | Pay your carrier directly at your rates | Pay the provider for telephony |
| Numbers | Keep your existing DIDs | Provision numbers through the provider |
| Rates | Your negotiated per-minute rates | Provider's published rates |
| Setup effort | Add carrier + gateways + DID; whitelist SIP IP | Connect the provider account |
| Time to live | Longer — SIP config and peering | Faster — account connect, provision, call |
| Direction | Inbound and outbound | Inbound and outbound |
| Best for | Existing trunk, negotiated rates, high volume | Fast start with no trunk of your own |
Control: who owns the carrier layer
With BYOC, you own the carrier layer end to end. You choose the SIP host, the transport (UDP, TCP, or TLS), the port, the authentication method, the tech prefix, the E.164 leading-+ behavior, and the DTMF mode. That is real control, and it is what infrastructure and telecom teams want when they already run a trunk and know their carrier's quirks.
With a provider integration, you deliberately hand that layer off. The provider abstracts the carrier away. You do not touch gateways or SIP IPs; you connect an account and use the numbers it gives you. Less control, but also less to get wrong.
Neither is universally better. Control is an asset if you have the expertise to use it and a liability if you just want calls flowing without becoming a SIP administrator.
Billing: pay the carrier or pay the provider
This is often the deciding factor.
BYOC — pay your carrier directly. The AI runs on top of your existing telephony, and your carrier keeps billing you at your negotiated per-minute rates. If you have spent time earning a good rate card, BYOC preserves it. Nothing gets marked up and resold back to you. For high-volume operations, keeping the direct carrier rate is frequently the whole reason to choose BYOC.
Provider integration — pay the provider. Telephony is billed by Twilio, Exotel, or Plivo at their published rates. That is simpler if you have no carrier relationship and do not want to build one. You trade a potentially higher per-minute cost for zero carrier procurement.
If you already have negotiated rates, BYOC almost always wins on cost. If you are starting from nothing, the provider's convenience usually outweighs the rate difference until volume grows.
Numbers: keep yours or provision new
BYOC — keep your DIDs. Point the numbers you already own at an AI agent, in E.164 format. No porting, no re-provisioning. This matters enormously if your numbers are printed on invoices, listed in directories, embedded in ad campaigns, or wired into your CRM. Callers dial the same number; it just reaches an AI agent now.
Provider integration — provision through the provider. You get numbers from the provider's inventory. Clean and fast if you are starting fresh, but it means new numbers rather than your existing ones (unless you go through a separate porting process with the provider).
If keeping your current numbers is non-negotiable, that alone points you to BYOC.
Setup effort and time to live
BYOC takes more up-front work. You add a carrier with its SIP host and auth mode, define inbound and outbound gateways with transport and port, whitelist the Edesy SIP IP for static-IP trunks, and point a DID at an agent. For standard trunks this is self-serve in the SIP Trunks settings; for complex peering, the Edesy team helps you onboard. The reward for that effort is control and your own rates. A full walkthrough is in How to Connect Your Own SIP Trunk to an AI Voice Agent.
Provider integration is faster to live. Connect the account, provision a number, assign it to an agent, and you are calling. There are no gateways to define and no SIP IP to whitelist. If speed to first call is your priority, this is the shorter path.
Decision framework
Check the boxes that apply to you.
You should bring your own SIP trunk (BYOC) if:
- You already have a SIP trunk with a carrier you trust
- You have negotiated per-minute rates worth keeping
- You must keep your existing phone numbers exactly as they are
- You have the telecom knowledge (or onboarding help) to configure SIP
- You run enough volume that paying the carrier directly matters
You should use a provider integration if:
- You have no trunk or carrier relationship today
- You want numbers and calling live as fast as possible
- You would rather not manage SIP gateways and IP whitelists
- You are fine paying the provider's published rates
- You are piloting and want the lowest-friction start
If three or more boxes apply in one column, that is your answer. And you are not locked in — many teams start on a provider to launch quickly, then move to BYOC once volume justifies keeping carrier rates.
What stays the same either way
Whichever route you pick, the AI voice agent itself is identical. Both options support inbound and outbound calling, both let you assign numbers to specific agents with their own prompts and integrations, and both terminate on Edesy's managed SIP infrastructure via the Edesy Voice API. You can also bring your own AI keys and providers with BYOK & BYOP, or skip the phone network entirely for in-app calls with WebRTC Browser Calls. The telephony choice does not constrain the agent's capabilities.
Frequently asked questions
Is BYOC cheaper than a provider integration?
Usually, if you already have negotiated carrier rates. With BYOC you pay your carrier directly at your rates, so nothing is marked up and resold to you. With a provider integration you pay Twilio, Exotel, or Plivo at their published rates. If you are starting from scratch with no carrier deal, the provider's convenience often outweighs the per-minute difference until your volume grows enough to justify a trunk.
Can I keep my existing phone numbers with a provider integration?
Not automatically. Provider integrations typically provision numbers from the provider's inventory. Keeping your current numbers as-is, with no porting, is a strength of bringing your own SIP trunk: you point the DIDs you already own at an AI agent in E.164 format. If your numbers are printed on invoices or embedded in campaigns, BYOC preserves them without a porting project.
Which is faster to set up?
A provider integration is faster to first call. You connect the account, provision a number, and assign it to an agent, with no gateways or SIP IP whitelisting. BYOC involves more configuration — carrier, inbound and outbound gateways, transport and port, authentication, and a DID — but rewards that effort with control and your own carrier rates. The full BYOC walkthrough is in How to Connect Your Own SIP Trunk to an AI Voice Agent.
Do both options support inbound and outbound calls?
Yes. Both BYOC and provider integrations handle inbound and outbound calling. With BYOC you define inbound and outbound gateways on your own trunk; with a provider integration the provider carries both directions. The choice is about carrier ownership, billing, and numbers, not about which directions of calling you can run.
Can I switch from a provider to BYOC later?
Yes. A common pattern is to launch on a provider integration for speed, then move to BYOC once call volume makes keeping direct carrier rates worthwhile. Both connect to the same agent, so switching the telephony layer does not change your prompts, integrations, or how numbers map to agents.
Conclusion
The choice between a SIP trunk and a provider integration is really a choice about starting point. If you already own a trunk, want your negotiated rates, and need to keep your numbers, bring your own carrier. If you have no telephony yet and want to be calling today, a provider integration is the fastest route in. Both do inbound and outbound, and both run on the same AI agent, so neither decision boxes you in.
Ready to decide? If you have a trunk, start with Bring Your Own SIP Trunk. If you would rather use a provider account, see Telephony Providers. Either way, you can sign up and be connected in one sitting.
Related resources
- Bring Your Own SIP Trunk — connect your own carrier and keep your rates
- Telephony Providers — use a Twilio, Exotel, or Plivo account
- BYOK & BYOP — bring your own AI keys and providers
- WebRTC Browser Calls — in-browser calling with no trunk
- How to Connect Your Own SIP Trunk to an AI Voice Agent — the step-by-step BYOC setup
- AI Voice Agent — the full voice agent platform