Synthflow on a Jamaican Number: Connect Your Phone System with WOCOM SIP
Synthflow is a no-code platform for voice agents: you design the conversation as a flow, connect it to your calendar or CRM, and publish it to a phone number. Connecting your own phone system over SIP, which is what you need to use a Jamaican number from WOCOM, is an Enterprise feature. Accounts on other plans see an Upgrade button in place of the import option. Confirm your plan before you start.
What You Need
- A WOCOM number on Cloud PBX or a SIP trunk.
- A Synthflow Enterprise workspace with an agent built and tested.
- From WOCOM: the SIP domain or proxy that Synthflow sends outbound calls to, and SIP credentials if your trunk uses them. Synthflow does not issue SIP credentials of its own.
Step 1: Choose Your Region
Under Settings → Workspace Settings → Preferences → Customer Region, choose the region for your calls. For Jamaica the US region is usually the shortest path. The inbound host follows the region: sip.us.synthflow.ai for the US, sip.eu.synthflow.ai for Europe, or the global sip.synthflow.ai.
Step 2: Import the Number
- Open Phone Numbers → New Phone Number → Import a Custom Number.
- Set Phone Provider to Custom and enter the number in E.164 form: +1876XXXXXXX.
- SIP Domain: the WOCOM address that outbound calls go to. If WOCOM gives you an outbound proxy instead, enter it in Outbound Proxy; it takes priority over the SIP Domain.
- Username and Password: the credentials WOCOM issued, if any.
- Protocol: UDP, TCP or TLS.
- If WOCOM asks Synthflow to register like a phone, turn on Enable outbound SIP registration. The default re-registration interval is 300 seconds.
- Save, then note the Origination URI Synthflow shows. That is the address WOCOM sends your calls to.
Developers can do the same through the API with POST /custom-numbers.
Step 3: Ask WOCOM to Route the Number
Send WOCOM support the following:
- The Jamaican number(s) you want answered by the AI, written in E.164 form (for example +1876XXXXXXX or +1658XXXXXXX).
- The platform's SIP address for inbound calls (shown below for this platform).
- Whether the AI also needs to place outbound calls, and from which number.
- Where calls should go if the AI hands a caller to a person: an extension, a ring group, or a mobile number.
Include the Origination URI from step 2, for example sip:+1876XXXXXXX@sip.us.synthflow.ai:32681. Note the port: Synthflow uses 32681 for UDP and TCP and 32682 for TLS, not the usual 5060 and 5061. A call sent to 5060 will fail. Synthflow publishes its signalling addresses: in the US, 35.237.42.43, 34.139.4.161 and 4.138.180.50. Media uses UDP ports 10000–60000 from a further set of published addresses, which WOCOM can allow on your route.
Codecs, Keypad and Encryption
Synthflow supports G.711 μ-law, G.711 A-law and Opus. It does not list G.722, so the call will use G.711 between WOCOM and Synthflow. Keypad presses are sent as RFC 2833 events or SIP INFO. For encryption, Synthflow uses TLS 1.2 or later and SRTP where the far end supports it. If SRTP cannot be agreed, audio falls back to plain RTP while signalling stays encrypted. Ask WOCOM which mode your route supports.
Transfers
Synthflow can transfer a caller to a SIP address. A cold (blind) transfer uses SIP REFER, so ask WOCOM to allow REFER on your trunk. Warm transfers, where the agent introduces the caller first, are described differently across Synthflow's documentation. Test the exact behaviour on your account before you promise it to callers.
What It Costs
Synthflow does not publish a per-minute price for SIP connections. Enterprise plans are sold on annual contracts. Model choice also depends on your plan: since August 2026, non-Enterprise accounts can only use Synthflow's own language model.
Is Synthflow Right for You?
Synthflow suits larger teams that want a visual builder and are already on, or ready for, an Enterprise contract. For a small or medium business, WOCOM AI is included with Cloud PBX with no separate contract. Compare the choices in our platform comparison, or talk to WOCOM about routing your number to Synthflow.
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Book a Demo Contact SalesEverett Kildare is WOCOM's voice and infrastructure specialist, with more than 25 years of experience designing and running carrier-grade voice, SIP and virtualization infrastructure. Holding a BSc in Information Technology, he has built, secured and migrated phone systems for businesses of every size. Everett writes WOCOM's technical coverage of SIP trunking, cloud PBX, contact centres, business continuity and migration.