Inbound vs Outbound SIP Trunk – What’s the Difference?

The telephony industry is riddled with acronyms and jargon. It’s not surprising that many people feel intimidated. The situation is not helped by the fact that modern enterprise phone systems offer a wealth of choices. Too many, some might even say. So, let’s dive in and see what the landscape looks like, shall we?

What Are Your Options?

When it comes to Internet delivery or VoIP (Voice over Internet Protocol), enterprises have two options:

• SIP trunking
• Hosted services

Business uses traditional phone systems a.k.a. landlines, a typical call would first go to the PBX (Private Branch Exchange). From there, the call is routed through physical lines to its destination over the PSTN. SIP trunking has a similar set up except that your PBX has to be SIP compatible. And there are no physical lines connecting you to service provider. Instead, the call travels over your data network.

Hosted VoIP services go one step further. All the hardware and software – including the IP PBX – is not physically located in your office. The service provider delivers a dial tone and all calling features over the Internet. For many businesses, these services are critical. They don’t have to waste time in maintaining systems. Or invest a lot of money in purchasing equipment.

Inbound vs Outbound SIP Trunks

There are many ways to classify enterprise phone calls. For example, some calls are voice only while others include video. You can also group calls according to how many people are participating in it. So you can have one-to-one calls or conference calls with multiple speakers.

You can also classify calls according to the direction they travel. Calls that employees make to external entities – customers, partners, suppliers, regulators, etc. – are called outbound calls. Inbound calls go in the opposite direction. When customers or anyone else from outside the organization contact someone inside, it is an inbound call.

While the distinction between inbound and outbound calling may seem trivial, it is actually important. One reason is that you can actually separate the two. For instance, an organization may decide to use SIP trunks for outbound calls only. They can continue using the existing PRI lines for inbound calls.

Why would you do that? A business may want to ease into the transition to VoIP gradually. They may have existing equipment that they don’t want to throw out immediately. Some businesses like to test new equipment before committing wholeheartedly to it. Whatever be the reason, you can use SIP trunks in a single direction only.

The Differences between Inbound vs Outbound Calling

There are a plethora of features that SIP trunking offers, in conjunction with an IP PBX. Some features affect inbound calls only, while others impact outbound calls.

The most common features that organizations use for inbound calling are:

• Voicemail – You with multiple options here. You can have visual voicemail delivered directly to employee inboxes. You can enable automatic transcription and recording.
• Call routing – Any modern business has complex routing needs. You may have some employees working from home, from a client site or traveling. But no one should miss incoming calls. You can set up routing rules which dictate where calls should go, based on the time of the or other variables.
• Toll-free & DID numbers etc – Toll-free numbers allow customers to contact you without incurring long-distance charges. DID numbers allow you to assign direct numbers to certain employees, without maintaining separate physical lines.

On the other hand, examples of outbound calling features are:

• Integration with CRM software – This allows agents to call customers from within an application. There is no need to switch apps just for a call.
• Caller ID – This is a crucial feature for any business. Any call going from your company has to show the correct number on the caller ID. With VoIP, you can show the correct number even if you are using a different device or calling from a different location. The customer never has to know that you’re not at your desk.
• Call data records – Most organizations maintained detailed call data records. You need the data to analyze call volume, traffic, and spot issues before they blow up.

Should You Use Both?

Although you can use just one, most companies prefer to go all in with SIP trunking. That’s because the upgrade almost always saves money. While the exact amount might differ from one company to the next, practically no one will spend more on VoIP than older landlines.

Upgrading all at once also saves you time – you don’t have to implement the project in phases. You don’t have to reconcile two types of equipment at the same time. There are very few instances where enterprises go back to landlines after using VoIP. So it makes sense to deploy the entire system at once.

As always, analyze your requirements and select a system that suits your needs.