Phone numbers in 130+ countries for Retell AI agents
A neutral telephony partner for your Retell stack
Retell connects to any telephony provider through elastic SIP trunking, and recommends it as the path for production numbers. By default that points at Twilio or Telnyx underneath. didlogic is that same elastic SIP trunking path, with deeper global coverage and no per-channel billing.
didlogic only sells voice infrastructure. Our own Autonomous System (AS13006), 12 physical PoPs, 240+ carrier agreements, and direct Tier 1 peering exist to carry your calls, not to compete with Retell. You keep the agents you built in Retell. We handle the numbers and the network underneath.
That neutrality matters when you scale. Some SIP providers in the AI voice space also sell their own agent platforms, which puts them in conflict with the Retell stack you chose. We do not have an agent product. We will not have one.
didlogic is a listed Retell integration partner, with a published profile in the Retell app partner directory and a step-by-step setup guide in the didlogic docs.
Connect Retell to a didlogic number in three steps
Buy a local or toll-free direct inward dialing (DID) number in any of 130+ countries from the didlogic portal. Provisioned in seconds.
In Retell, open Phone Numbers and choose “Connect to your number via SIP trunking.” Enter your number in E.164 format, set the Termination URI to your nearest didlogic proxy (for example, sip.nl.didlogic.net), and add your 5-digit SIP login and password.
In the didlogic portal, edit your number, set “Forward to” to a SIP URI, and send it to your Retell address ([email protected]). Assign an inbound or outbound agent in Retell and place a test call. A sales engineer helps with SIP setup, so many teams place their first test call the same day.
What Retell teams get with didlogic
Local and toll-free DIDs in 130+ countries, with licensed local voice in 17 of them. Retell’s built-in number purchasing runs on its telephony partners with limited international reach. didlogic does not stop at a handful of markets.
Sub-20ms added media latency on 80% of calls on the carrier-side leg, measured across our 12 PoPs. Direct Tier 1 peering with PCCW, GTT, Telia, and NTT keeps the audio path short before it reaches Retell’s SIP server.
Elastic SIP trunking with username and password authentication, TLS signaling and SRTP media encryption on request, and G.711 for a transcoding-free path. Everything Retell’s custom telephony specification asks for.
One SIP account handles inbound agents, single outbound calls, and batch campaigns from CSV or the Retell API. CLI rotation cycles your number pool to keep outbound pickup rates healthy. Answering machine detection (AMD) passes through so the agent reacts correctly to voicemail.
Pay per DID and per minute. No charges per concurrent channel, no seat licenses, no tier gates on CPS for AI-native accounts. Concurrency scales without a separate billing conversation.
Provision numbers and configure trunks from Claude Code, Cursor, or any MCP client at mcp.didlogic.com. One less portal to switch into while you are already building Retell agents.
| Retell requirement | didlogic support |
|---|---|
| Elastic SIP trunking (recommended path) | Supported |
| Termination URI to your SIP server | didlogic regional proxy (for example sip.nl.didlogic.net) |
| Username and password authentication | Supported, recommended (Retell's SIP server has no static IP) |
| TLS signaling (transport=tls) | Supported on request |
| SRTP media encryption (with TLS transport) | Supported on request |
| G.711 (PCMU/PCMA) codec | Supported |
| E.164 number format | Supported |
| Inbound routing to Retell SIP URI | Forward to [email protected] |
| Outbound: manual, batch CSV, and API | Supported on the same SIP account |
| SIP REFER for human hand-off | Supported, enable once on your didlogic account |
| DID porting to didlogic | Paperless LNP in 8 countries |
The numbers that matter for AI voice
Added carrier-side media latency on 80% of calls, measured across our 12 PoPs.
Network availability target, backed by owned infrastructure (not third-party cloud).
Median DID provisioning time from portal checkout to SIP-ready.
With licensed local voice, not just pass-through.
Deploy in the EU, UK, and APAC without regulatory friction
didlogic routes calls through its own regional data centers. Voice traffic stays on domestic infrastructure where required, keeping call handling aligned with local data processing laws.
Direct connectivity to 80% of Tier 1 carriers and national operators worldwide. Calls hand over to the recipient’s local mobile network, not through foreign gateways.
EU and APAC DIDs are activated on domestic mobile networks. Outbound calls originate from in-country IPs with compliant caller IDs, so they arrive as domestic traffic rather than being flagged as foreign.
Our regional legal and telecom engineering teams track regulatory changes across the countries we serve. Call processing adjusts proactively when rules change, so your Retell agents stay compliant without a ticket on your side.
What teams build on Retell + didlogic
Route inbound PSTN calls to a Retell agent on a local number in any market, 24/7. didlogic delivers clean caller ID on every inbound call, which your Retell inbound webhook can use to recognize the caller.
Local caller IDs that get answered. CLI rotation cycles your number pool to keep pickup rates healthy. Outbound campaigns ship without per-channel concurrency taxes on the carrier side.
Run Retell batch calls from a CSV or the API over didlogic numbers. AMD passes through so the agent knows when it reaches a voicemail. Transfer to a human via SIP REFER when intent is high.
Pair Retell agents with local numbers across 130+ countries. One Retell deployment, native-language coverage in every market you sell into.
Many platforms have gaps in MENA, parts of APAC, and Eastern Europe. didlogic carries licensed local voice in 17 markets and sources DIDs in 130+ countries, including the ones most carriers refuse.
Our clients
FAQ: SIP trunk for Retell AI agents
Does didlogic work with Retell AI?
Yes. didlogic connects to Retell through elastic SIP trunking, which is Retell’s recommended path for production numbers. You set the didlogic regional proxy as your Termination URI, authenticate with your 5-digit SIP login and password, and forward your didlogic number to your Retell SIP address. A test call typically goes through within minutes of finishing setup. A step-by-step guide is published on the didlogic docs.
How do I connect a phone number to Retell with didlogic?
Buy a DID in the didlogic portal, then in Retell open Phone Numbers and choose “Connect to your number via SIP trunking.” Enter the number in E.164 format, set the Termination URI to your nearest didlogic proxy, and add your SIP login and password. Back in the didlogic portal, forward the number to [email protected]. Assign an inbound or outbound agent and place a test call.
How does didlogic compare to Twilio for Retell?
Two differences. First, no per-channel fees, which is the line item that grows fastest on outbound AI campaigns. Second, deeper global DID coverage, 130+ countries with licensed local voice in 17, versus a smaller direct-coverage footprint. Retell connects to both through the same elastic SIP trunking path, so what changes is the telephony layer underneath. See our Twilio alternative for AI voice page for a full breakdown.
What does Retell cost, and what does didlogic add to it?
Retell bills its own per-minute rate for the AI agent. didlogic is a separate telephony layer billed per DID and per minute, with no per-channel charges. You pay Retell for the agent and didlogic for the numbers and minutes underneath. The two are independent line items.
Does Retell on didlogic support outbound and batch calls?
Yes. The same SIP account handles single outbound calls, batch campaigns uploaded as CSV, and calls triggered through the Retell API. Because didlogic does not charge per concurrent channel, batch concurrency scales on the carrier side without a telephony tier upgrade.
Does didlogic support SIP REFER for call transfers on Retell?
Yes. Retell’s Call Transfer function can use SIP REFER to hand a caller to a human. SIP REFER needs to be enabled once on your didlogic account, so contact your account manager before you configure it. The transfer destination uses the format sip:number@proxy:5060 with the transfer method set to SIP REFER.
Which IP addresses or hosts do I need for Retell on didlogic?
On the didlogic side you forward inbound calls to [email protected] and point your trunk at a didlogic regional proxy such as sip.nl.didlogic.net. Because Retell’s SIP server does not use a static IP, username and password authentication is the recommended method rather than IP allowlisting.
Can I get Retell-ready numbers in countries Retell does not sell directly?
Yes. didlogic supplies numbers in 130+ countries, including markets where most providers have gaps, such as parts of MENA, Southeast Asia, and Africa. Once the number is provisioned on didlogic and connected through elastic SIP trunking, it works with your Retell agents like any other number.
Can I port my existing number to didlogic for use with Retell?
Yes. didlogic supports paperless LNP in 8 countries and manual porting in most others, with no downtime during the move. A common pattern is porting numbers to didlogic for voice while keeping another provider for SMS. Retell does not care which carrier owns the number once it is connected by SIP trunk.
Why do my Retell calls drop during silence?
This is usually RTP inactivity. When the agent is processing, no audio flows in either direction, and intermediate devices can time out the media stream. didlogic keeps the media path live across those gaps. If you see drops on another provider, the fix is RTP keepalives or a longer RTP inactivity timeout on the carrier side.
Should I use Retell or Vapi, and does didlogic work with both?
didlogic is the telephony layer underneath either one, so the choice of orchestrator is yours to make on features and pricing. If you run both, the same didlogic numbers and SIP account work across them. See our Vapi SIP trunk page for that setup.
Can I bring my own carrier to didlogic for Retell?
Yes. If you already hold carrier relationships or numbers, didlogic supports a bring your own carrier (BYOC) model alongside our own DID inventory, so you can consolidate routing for your Retell agents on one network.
Free credits on signup. No payment required. No commitment for 30 days.