What Is SIP Trunking

December 17, 2020 // Product

SIP Trunking enables phone calls to be sent and received through an IP network. In the past, the Public Switched Telephone Network (PSTN) operated using a system of analog transmissions via copper loops. Now, most modern communications have moved away from this analog system to embrace Voice over Internet Protocol (VoIP) meaning that calls use digital packets over modern networks rather than physical phone lines.

Session Initiation Protocol (SIP) emerged as the leading VoIP protocol, and is now supported across the industry. A SIP Trunk connects an organization’s PBX (private branch exchange) phone system to the PSTN using private networks or the internet, and can support multiple simultaneous calls on one trunk.

Benefits of SIP Trunking

In our increasingly digital world, many companies have switched to SIP Trunking. The heightened level of flexibility and modernization offers many benefits over the traditional analog phone lines of the past. Elastic SIP Trunks can scale to account for increased demand on the fly. Instead of having to add more physical phone lines and then upgrade your PBX to handle the increased capacity, you may just be a simple config change away. This flexibility enables businesses to stay competitive and scale easily based on their needs.

Furthermore, if a company wants to move offices or embrace a work from home model, as many have done recently, it is easy to keep the same phone numbers. While phone numbers were bound to a geographical location in the past, now all that’s needed is a decent internet connection, allowing smooth transitions between locations without communication interruptions.

One of the most notable benefits of SIP Trunking is the cost effectiveness. Typically, SIP Trunking is cheaper than Plain Old Telephone Service (POTS), and it is also common to see shorter contracts.

Inbound vs. Outbound

SIP Trunking offers the ability to receive inbound calls, place outbound calls, or do both. Inbound is also referred to as SIP Origination, and outbound is also referred to as SIP Termination.

Inbound SIP Trunks are configured to deliver the calls received on your phone number(s) to your switch so they can be routed to the desired destination. Outbound SIP Trunks are configured to accept the outgoing calls placed through your switch and deliver them to the PSTN to be routed to the desired phone number. While most companies use both inbound and outbound, there are certain use cases where only one needs to be deployed.

For example, a company who uses SIP Trunking in order to contact their customers about an upcoming delivery may only need outbound SIP Trunks. While their agents place calls to inform customers about a pending delivery, they may not be set up to receive inbound calls. Rather, they use the phone number that is routed to their company’s IVR as the caller id on the call, so if a customer calls back, they can check their delivery status on their own.

On the other hand, a company who has a toll-free number listed for specific inquiries might use inbound SIP Trunking only. Their toll-free number exists to accept inbound calls in order to allow customers to find an answer to their questions. Once their customer gets the information they need, the conversation concludes, and any follow up might be handled outside of the phone line, via email or snail mail. In this case, inbound trunks are sufficient, allowing the company to deploy only the functionality they need, while saving on costs.

There are several additional features that can be used with both inbound and outbound trunks. Simultaneous call limits, call recording, call recording storage, early media settings, and disaster recovery can all help to protect your systems, monitor call quality, and enable you to fail gracefully when your network goes down.

SIP Trunking With Voxology

When it comes to communications, you shouldn’t have to sacrifice quality in order to save money. Our highly scalable SIP Trunks combine a premium global carrier mix with rich features for both inbound and outbound, allowing companies to scale up or down with no carry cost. Additionally, we offer competitive rates to ensure that the service is as cost effective as possible.

The ability to configure multiple trunks to prepare for failures ensures a greater peace of mind when it comes to large scale, critical communications. Not only are our SIP Trunks user friendly, they can be set up in minutes using the Portal (UI) or API.