Grandstream UCM

How Voice Logica connects

The UCM registers a SIP trunk to Voice Logica (way 1). Voice Logica creates the trunk and gives you a server, a username and a password; on the UCM it is a normal Register SIP Trunk, as with any phone provider. The UCM connects out, so no port forwarding is needed.

• Calls the UCM sends to this trunk are answered by the AI agent.
• The agent transfers callers back over the same trunk, and the UCM rings the extension through an inbound route.

No licence is needed: SIP trunks are built into every UCM. The same menus apply to the UCM6300 / 6300A, UCM6200 (end of life), UCM6510 and CloudUCM.

1. Create the connection in Voice Logica

Telephony - Trunks - Connect your PBX, pick Grandstream UCM and the agent. Keep the dialog open: it shows the values and changes to Connected when the UCM registers.

2. Add the trunk on the UCM

1. Extension/Trunk → VoIP Trunks → Add, type Register SIP Trunk.
2. Provider Name Voice Logica. Host Name = the server from the dialog (port 5060). Transport UDP.
3. Username and Auth ID = the username, Password = the password.
4. Leave Keep Trunk CID off, so each extension’s caller ID is kept.
5. Advanced Settings: Codec Preference PCMA first, then PCMU. DTMF Mode = RFC4733. Turn on Enable Heartbeat Detection. Leave Auth Trunk off: with it on, the UCM challenges our calls and transfers back fail.
6. Save and Apply Changes. The trunk shows as registered within a minute.

UCM6100 (older firmware): the same fields are under PBX → Basic/Call Routes → VoIP Trunks → Create New Trunk, and routes under PBX → Basic/Call Routes.

3. Send calls to the agent

Choose which calls the agent answers:

• A short code or prefix: Extension/Trunk → Outbound Routes → Add, with a Pattern (for example _9XX or a dedicated code) and Use Trunk = the Voice Logica trunk.
• A number, an IVR option, a ring group or queue overflow, after-hours calls: point that destination at the outbound route above.

4. Let the agent transfer back to extensions

Extension/Trunk → Inbound Routes → Add for the Voice Logica trunk: DID Pattern that matches your extensions (for example _2XX), destination By DID or the extension. Then, in Voice Logica, add the extensions as transfer destinations on the agent: an External destination with the extension number (for example 201), or a User with that extension. Use Warm transfer, so the agent comes back and takes a message when nobody answers.

5. Check it works

• The dialog says Connected. In Voice Logica, the trunk’s SIP logs show each REGISTER and our reply.
• Dial the short code or the number from an extension: the call appears in Calls with the agent.
• Ask the agent for a colleague: the extension rings.

Good to know

• Behind NAT: PBX Settings → SIP Settings → NAT, set External Host (your public IP or hostname) and Local Network Address. On UCM630x, also turn off UCM RemoteConnect (MediaNAT traversal) if trunk audio is one-way.
• Turn off SIP ALG on the office router.
• Each call with the agent uses one trunk channel; a Warm transfer uses two until it connects.
• No trunk at all? A UCM can also take Voice Logica as an extension through an edge device, but the trunk is simpler.