What is a SIP trunk

SIP trunk shows up in the request next to the system and the phones. It is not an extension. It is not the PBX. It is the path of the calls between the company system and the public numbers — what used to be a bundle of lines at the exchange.

Palo Security supplies Grandstream, Yeastar, Avaya, Mitel and 3CX PBX systems, and Fanvil phones. The SIP trunk is the operator line to that system. PBX capacity, the number of extensions and what the line needs are set in the quote.

SIP and trunk

SIP is how the call travels on the data network. Trunk is the bundle: several calls at once on that line, instead of one wire per extension. Together, a SIP trunk is the PBX link to the operator over the internet, with the company numbers.

What it is not

• It is not the Fanvil phone on the desk. That is the extension.
• It is not the Grandstream, Yeastar, Avaya, Mitel or 3CX system. That is the PBX.
• It is not the patrol radio or the meeting-room video. Those are other articles.

Where it sits

On an on-site PBX, the SIP trunk arrives at the box in the office. On a cloud PBX, the line usually closes on the off-site system; the office needs internet for the extensions. Cloud or on-site is in the article cloud PBX vs on-site PBX. Both need a line for calls to leave and come in.

What the site needs

The SIP line travels on the network. With no stable internet, outbound calls fail. How many calls at once — how many people talk outside at the same time — sets the line, not an invented channel count on the sheet.

What to say in the request

1. How many extensions and how many outbound calls at once the office needs.
2. Whether the system is on-site or cloud, and whether a line already exists with the operator.
3. Whether a Grandstream, Yeastar or other PBX already sits on site.

We do not invent the line. The system, the phones and the SIP trunk close together. Tell us the office and we prepare the quote.