What is an Outbound SIP Trunk for VoIP?

Business owners constantly optimize their budgets and spending. That’s because you have to be efficient to succeed. There are a lot of areas to focus on – people, technology, product, distribution etc. As priorities and costs change, it is up to the business to maximize profitability.

Communication is one of those areas where there is room to optimize. Most businesses have shifted towards VoIP calling over the past few years. The two biggest reasons are to reduce costs and use advanced features.

SIP trunking is one way to implement Internet-based calling within an enterprise. So, let’s take a look at what SIP is and what it does.

Session Initiation Protocol

VoIP stands for Voice over Internet Protocol or in other words, Internet calling. SIP is a specific protocol that allows you to implement VoIP. It stands for Session Initiation Protocol. It is a technology that handles creating, managing and terminating VoIP sessions.

A session can consist of two or more parties and include video as well. SIP manages everything from regular two-way audio calls to multi-person video conference calls. Providers use different protocols to manage other aspects of Internet calling.

What Is a SIP Trunk?

A SIP trunk is the digital equivalent of the physical lines that used to connect businesses with phone operators. SIP trunks are virtual i.e. they connect your business to the SIP provider over existing data connections. The SIP trunk connects your on-premise phone system (powered by an IP PBX) to the outside world.

The IP PBX within the company manages all your internal communication. This often includes call centers, IVR, IP phones, conference calls etc. It also routes the calls and outside entities through the SIP trunk where necessary. Some trunks are metered while others offer unlimited outbound calls. It depends on the providers’ business model and pricing plans.

SIP trunks from a reputed vendor can easily handle multiple concurrent calls. They are limited only by available bandwidth. They provide most of the features of analog trunks that enterprises need.

But they also offer the ultimate in flexibility. You can add channels whenever you need. You never have to worry about exceeding capacity. Most providers can provision extra channels almost instantly.

Cost of Outbound SIP Trunks

SIP trunking costs are different from hosted VoIP. Typically, a business will pay a setup fee as well as a monthly charge for using a single SIP trunk. Unlike hosted services, you are not charged for phone services like call hold or voicemail. Your IP PBX takes care of all that.

In most cases, one channel can support one call at a time. You can always provision extra channels if you are close to reaching capacity. For companies that make thousands of calls per day, SIP trunking is very inexpensive.

Suppose you have 40 channels provisioned by the vendor. On most normal days, you do not exceed 33 – 35 calls simultaneously. If call volume suddenly increases, you can provision extra channels as you need them. Unlike traditional trunks, you do not have to purchase them in preconfigured bundles. The only thing you have to consider is whether you have the bandwidth.

Businesses that can afford to invest in SIP trunks and their own phone systems have lower costs per call. SIP trunking is a great alternative for businesses that experience high call volume. Over the lifetime of the equipment, the cost of ownership is significantly less.

Features of SIP trunks

SIP trunks offer many advantages over traditional copper lines. In the case of outbound SIP trunks, you can provision extra channels instantly. There is no need to wait for physical wires, technicians or service appointments.

This allows your business the flexibility to react to changing circumstances. You are not locked into any long-term contract with hefty fees for modifying terms or terminating services.

SIP trunks allow you to budget financial resources effectively. You do not have to worry about unexpected spikes in your monthly bill. You can easily estimate the number of channels you require. Then if you need more or less, adjust accordingly.

SIP trunks are also very secure. Security is needed to protect your organization against fraudulent calls and unauthorized charges. Hackers and criminals also try to get into your systems via the phones. Those same security measures also ensure privacy for your communication. It means outside entities cannot intercept your calls or eavesdrop on conversations.

In spite of these advantages, quite a few organizations opt for hosted services. Mostly they lack the in-house expertise to manage the phone system. Others may not have the financial resources to invest upfront. But for an organization that has access to financial and technical resources, SIP trunking is the best option to implement VoIP.