SIP Trunk

SIP Trunk connection por enterprises looking for quality

SIP Trunk rates

Ask for quotation now

Conforme a la Ley Orgánica 15/1999 de Protección de Datos de Carácter Personal, le informamos que sus datos personales de contacto han sido incorporados a un fichero denominado Usuarios Web, del que es responsable Telsome Spain, S.L.U., cuya finalidad es la gestión de las consultas realizadas por los usuarios a través de la web. Si desea ejercitar sus derechos de acceso, rectificación, cancelación u oposición, podrá dirigirse por email a

What is a SIP Trunk?

funcionamiento troncal sip esquema telsome sip trunk

A SIP trunk is a telephony service offered by VoIP providers that allows enterprises to connect their IPBX to the telephony network, making possible to make VoIP phone calls to fixed and mobile phone lines all around the world.

Phone calls are done using Internet Protocol and help enterprises save big amounts of money in calls and monthly fees.

With SIP Trunking enterprises no longer need RDSI connections in order to use several phone lines.

Benefits of using a SIP Trunk

The main benefit when changing to IP Telephony using a SIP Trunk are the savings, but there are more benefits..

Furthermore, most enterprises decide to migrate their PBX system to a VoIP trunking when their PBX hardware needs to be replace. Is in this moment when most enterprises replace it for a new IP PBX and start using the current technology: VoIP.

1. Big savings in monthly fees

The connection to the PTSN is cheaper than traditional telephony connections because you are using Internet instead of a big infrastructure. This results in great prices for phone lines, channels and other services.

2. Free internal calls

Phone calls among users of the same company do not use the PSTN and, therefore, are free for the enterprises. Phone calls among the VoIP provider users are normally also free.

3. Big savings in national and international phone calls

Rates for both national and international phone calls are cheaper with SIP Trunking because you are using VoIP telephony.

4. Channel scalability: hire more channels on the go

With traditional switchboards the number of channels depends on the infrastructure. Due to it enterprises had to hire channels in blocks of fixed numbers instead of just buying the number of channels they really needed. And, furthermore, a technician had to activate them.

With SIP Trunks you can hire as many channels as you need on the go and you will be able to use them instantaneously.

5. Mobility: change location with ease

The SIP trunk connects you to the PSTN using internet, no matter where you are located. That’s the reason that if it happens that you move your office you will only need Internet connection in the new one and connect your IP PBX and phone devices to have your entire phone system working in a moment.

No waiting times due to technicians and wiring, no problems of numbering availability. You will just need to have internet and connect your devices to keep working.

SIP Trunk Rates

SIP Trunk
3 channels

From 20,55€

SIP Trunk
7 channels

FROM 53,00€

SIP Trunk
​10 channels

FROM 71,43€

Why to choose Telsome SIP Trunk

Quality routing

Talk over the phone with the best voice quality. We select the best voice routing to ensure enterprises great voice quality on every single phone call.

Best stability

We use high quality resources, make sure we don't overload them and are continuously monitoring the service to offer you the most reliable SIP Trunk service.

Servers located in Spain

To minimise the path of our calls our servers are located in Spain, reducing latency and ensuring a better voice quality.

SIP Trunk Features

Main Codecs Available+ info

  • G.711 (A-Law; u-Law)
  • G729
  • Opus
  • SpeeX
  • H.264

Disaster BackUP+ info

  • Automated call forwarding in case of power outage or if Internet connection goes down.
  • Once connection is restored the service will automatically work as always.

Intelligent call forwardings+ info

  • Add rules and define where should phone calls be forwarded before they reach your IP PBX.

Block certain destinations+ info

  • Block outbound phone calls to specific destinations.
  • Manage them from your online panel.

Security+ info

  • IP restriction.
  • Consumptions limits.
  • Other secret security measures.

Help Guides and manuals+ info

  • Configuration manuals.
  • Problem solving guidelines.

Server Level Agreement+ info

  • SLA available.

No diferenciation between inbound and outbound channels+ info

  • The number of simultaneous calls you buy are both for inbound and outbound phone calls.
  • Extra channels included for phone calls to Telsome extensions and numbers.

Phone calls included on every SIP Trunk Plan+ info

  • All our SIP Trunk plans include phone calls to national or international phone numbers.
  • You can contact us if you need different phone rates.

Compatible with

These are some of the PBX compatible with SIP Trunk Telsome:

VoIP Devices



How does a SIP Trunk work?

sip trunk geographic numbers enterprise

YourVoIP provider connects your PBX to the PSTN with the SIP Trunk..

In order to provide phone lines to all enterprise users the VoIPprovider connects to PBX to the rest of the world (PSTN) with the SIP Trunk. The connection PBX-VoIP provider is done over Internet.

All phone extensons connect to the PBX, which is at the same time connected to the world with the SIP Trunk.

Internal phone calls - among enterprise users - do not get out of the PBX and don't even use the trunk. On the other hand, phone calls to external numbers need the SIP trunk to connect with people outside the enterprise network.

When a customer calls to the enterprise the VoIP provider connects the phone call to the PBX over Internet.Once the PBX receives the phone call it will have to route it to the right user based on different conditions, such as time, IVR, called ddi.

The internal routing and conditions are set up in the PBX. The PBX is where you create the phone extensiones, working time and days, queues, IVR, etc. You also specify the routings, phone numbers used and much more. sip trunk con extensiones conectadas a centralita ip

SIP Trunk requirements

In order to be able to take advantage of the benefits of using a SIP Trunk you need to use an IP PBX, have Internet connection, a VoIP provider and a SIP client:


Is the hardware managing the call routing to your enterprise phone numbers. There are several good PBX brands: Grandstream, Avaya, Elastix etc; o software como 3CX, FreePBX.

2. SIP clients

The SIP client can be a device or software used to make phone calls. It can be a VoIP phone, an ATA adapter, or a softphone in a computer, tablet or smartphone.

3. Internet

The PBX connects to the PSTN using Internet connection

We recommend 100kbs per phone call and fiber connection.

Important considerations

Configuration, maintenance and security needed

It's very important to understand that the enterprise is responsible for their PBX. A deficient set up may cause many problems to the enterprise communications.

In enterprises without VoIP tecnhology experience is more recommended to use hosted PBX.


The number of channels you hire sets the maximum simultaneous calls your enterprise can handle.The ideal choice is to hire the same amount of channels as simultaneous calls your enterprise handles in their peaks. Simultaneous phone calls can be easily upgraded.

Available band width

IT's important to know the available band width when people are working and using part of it. It may be necessary to enable QoS (always recommended when possible).

Cookie usage

We use our own and third party cookies to improve the browsing experience and offer content and relevant offers. On continuing browsing our web page we understand that you accept our cookie policy.