SIP trunk or call forwarding — which connection fits?

Call forwarding: the standard route

The assistant has a phone number of its own. You tell your line: "If I have not picked up after 25 seconds, forward the call there." That was the whole connection — by key code on your mobile, at your provider or in the router, as described in the basics article "Setting up call forwarding: the four routes and their pitfalls". Your number stays, your equipment stays, and the way back is open at any time: forwarding off, everything as before. Note: on a mobile, voicemail is itself a forwarding on no answer. The new forwarding replaces it, and ##002# deletes it too — to get voicemail back, set its forwarding up again.

SIP trunk: the direct line

A SIP trunk is — without the jargon — a direct telephone connection over the internet between your telephony and the assistant. Instead of handing calls on from A to B, the assistant becomes part of your phone system itself: a destination of its own, to which your system passes calls directly. There is no second call leg and no forwarding — which also removes forwarding's biggest weak point: the caller data comes through in full, and the CLIP problem (the assistant sees your number instead of the caller's) does not exist here.

The comparison at a glance

The rule of thumb by size and volume

• Sole trader to small team, the assistant replacing voicemail: call forwarding. No debate — the SIP route would be a sledgehammer for a nut.
• A business with a phone system that wants differentiated rules: still call forwarding, only now as a rule inside the system. When that makes sense is sorted out in "Do I need to change my phone system? No — and when you do".
• Permanently high call volume, several sites, the assistant as the first point of contact for every call: now the SIP conversation with your IT partner is worth having. A rough threshold: if telephony is infrastructure for you (your own phone system, your own admin or a service provider), you are a SIP candidate — if telephony is "the phone in your pocket", you are not. In that case, ask beforehand whether the assistant's provider offers a SIP trunk at all — not every provider does.

Honestly: SIP is a project, not a setting

So that no false impression arises here: a SIP trunk is agreed between two technical systems — number formats, encryption, failure behaviour, tests. That is done by an IT service provider or an experienced IT department, not by the business owner after hours. Anyone without an IT partner should simply not choose the SIP route — not because it is bad, but because call forwarding delivers most of the benefit without that project. The frequently cited SIP advantage of "clean caller ID" can also be softened: forwarding carried out by the provider's network generally passes the caller's number through — a test call shows whether yours does.

How scoco.ai is connected

scoco.ai is connected by call forwarding only; scoco.ai does not offer a SIP trunk. You keep your number and forward it to your assistant's scoco number — from the mobile, at your provider, on the FRITZ!Box or as a rule in your phone system. Nothing is rebuilt, and basic setup takes about 10 minutes. When a caller number is transmitted, the assistant offers to use it as the callback number — if the caller accepts, it is taken without being read back; a dictated number it reads back digit by digit. Whatever depends on the transmitted number — the number shown in the inbox, putting known callers from your contacts straight through, or a callback on the number the caller rang from — needs the real caller number; with a CLIP problem, it is your own. So check it with a test call.