Tech

Inter-Office Trunks

Published on:

June 21, 2013

Previous versions of the PBX allowed calls from one trunk to be routed through another for cost-effective call termination - this was commonly used by international offices. Now, the new inter-office trunk feature enhances this by assigning a dial plan directly to the trunk, offering greater flexibility in caller ID presentation. This allows businesses to optimize call routing without linking to specific extensions. While prepaid accounts aren’t supported, the feature enables broader applications, such as acting as a session border controller (SBC), handling LAN-WAN traffic, and translating calls between IPv4 and IPv6. Available from version 5.0.10i, this expands the role of the PBX in networked environments.

In previous versions of the PBX, there was already a setting, “assume the call comes from extension so-and-so”. This was a trick to make it possible for a call coming in on one trunk to end up on another trunk for outbound call termination.

The practical relevance for this was international offices could use this trick to locally terminate calls from their branch offices. For example, when a company had offices in Boston and Berlin, making a phone call in Germany from the Boston office could be done using the PBX in the Berlin office, saving international call termination fees.

We have now taken this to the next level by adding an “inter-office” trunk feature. Instead of using the dial plan of an extension, the trunk uses a dial plan directly. It also provides more flexibility in presenting the caller-ID: the presented caller-ID does not have to be linked to an extension. Of course this depends on the carrier’s ability and willingness to present caller-ID that aren't within the PBX address range.

Because extensions aren't charged any more, the interoffice trunk feature doesn't support prepaid accounts. Our feeling, however, is the practical relevance for this is relatively low anyway.

The term “office” goes beyond the example which I have made previously. Technically the PBX identified inbound traffic attached to a trunk, no matter if the call came from the same organization or from another source. This way, the PBX is able to perform general call routing functions and act as a general-purpose session border controller. Especially since the PBX is able to operate on multiple network interfaces, it can be used to translate traffic between LAN and WAN. Other scenarios, like translating calls between IPv4 and IPv6, or just transcoding codecs, are now also possible. Time will tell what customers want to see.

The inter-office trunk feature will be available from version 5.0.10i onwards.

Latest Articles

View All

Why Browser Calling is the Future of Business Communication

Vodia’s browser calling solution allows businesses to make and receive VoIP calls directly from any web browser, eliminating the need for apps or desk phones. It offers convenience, cost savings, and a wide range of features including chat, voicemail, call transfers, conference calls, video calls, and CRM integration. The system is secure, operating entirely within the browser to reduce exposure to malware, and scalable to support remote and hybrid work environments. With easy setup through the Vodia PBX web interface, organizations can streamline communication, improve productivity, and provide employees with a flexible, reliable, and fully integrated business communication experience.

August 13, 2025

Building Intelligent Voice Response Systems with Vodia's JavaScript IVR

JavaScript IVR transforms the way businesses handle incoming calls by enabling fully customizable, intelligent phone menu systems. Unlike static IVR setups with limited, pre-defined options, JavaScript IVR allows you to create dynamic call flows that adapt in real time based on caller input, business data, or even external API integrations. This means you can route calls more efficiently, automate complex processes, and offer highly personalized experiences to your customers. Whether you want to check customer records before transferring a call, adjust menu options based on time of day, or integrate with CRM systems for instant data access, JavaScript IVR gives you the flexibility and control to make it happen - all while improving efficiency and enhancing caller satisfaction.

August 11, 2025

Get The Support You Need Easily Through The Vodia Help Center On Jira

Vodia support is now easier to access through the Vodia Help Center on Jira, giving partners and customers a centralized platform to submit technical support tickets, ask sales or licensing questions, and suggest new features. With a valid license key, users can open detailed requests and track their status in one place. The portal also brings together Vodia documentation, the PBX API, and the Vodia forum, making it the go-to resource for everything Vodia. Whether you're troubleshooting, planning an upgrade, or just need guidance, the Help Center is designed to streamline your experience and connect you with the right support faster.

August 7, 2025