VoIP: SIP Trunking Vs. Hosted PBX

When it comes to implementing Voice over IP (VoIP), two options compete: SIP trunking vs. hosted PBX. Often there is confusion between SIP trunking and hosted PBX.

To get started, here are a few basic definitions:

  • PBX (Private Branch Exchange) is the private telephone switching system that connects external telephone services (PSTN) to user extensions within the organization.
  • SIP (Session Initiation Protocol) is the industry standard application-layer protocol used for peer-to-peer communications and multimedia, including voice, video, email and instant messaging.
  • IP (Internet Protocol) refers to the communications system to route data between computers or network nodes.

SIP trunking uses existing on-premise equipment (IP compatible PBX) and SIP, a set of rules for signaling and controlling multimedia communications, to establish voice and video calls between end points. The call routing is handled by a PBX system, and a telecommunications carrier provides the trunking, or connectivity, between this PBX and the public telephone network.

SIP trunking enables you to establish a virtual connection to the PSTN over your existing data circuit, so you no longer have to lease a dedicated Primary Rate Interface (PRI) for voice traffic. In essence, the SIP trunks replace your legacy PRI service. You benefit by having fewer connections with much more functionality and flexibility.

With hosted PBX, other than IP phones, the need for on-prem equipment is eliminated. The vendor hosts and operates the PBX functionality that manages call routing, voice mail, and other applications virtually, in the cloud. All that is needed for your business phones to work is IP connectivity and an Internet connection to access the vendor’s software, which routes the calls.

If you already have an on-premise PBX and want advanced VoIP capabilities, you have two options:

  • Continue using equipment that will always require upgrades or replacement, and add SIP trunking costs on top


  • Get rid of the local PBX immediately cutting on expenses and start enjoying a flexible hosted PBX subscription

Keep in mind that the benefits of hosted PBX are:

  • Low to no hardware and servicing costs
  • Expanded features and functionality
  • Access to the most recent PBX capabilities
  • Easy integration with third-party tools
  • Unlimited scalability
  • Geographical flexibility

Both technologies can simplify network management and lower IT costs by consolidating voice, video, and data traffic across a single network infrastructure. It is up to you to determine the best fit for your businesses needs and goals.

To review how your business can tap into the benefits of VoIP, consult with an expert. An agnostic technology agent or consultant can ask the right questions to determine what you need and how VoIP fits into what you’re trying to accomplish. In addition to assisting you with procurement, they can also handle ongoing care. If you would like to learn more about VoIP, click here. To fill out a contact form, click here and a representative will be in touch.

About Simplicity

Simplicity VoIP, based in Richmond, VA, provides hosted PBX, VoIP and business telephone solutions nationally to small, medium, and enterprise-level businesses for a comprehensive unified communications experience. Two distinct Class 5 geo-redundant VoIP platforms are offered in addition to fax-to-email, phones and equipment, and managed services. Named as Richmond’s 11th fastest growing company by Richmond BizSense, Simplicity VoIP’s key to success is its on-site service, installation and training supported 24/7/365 by a world-class client services team.