ISDN Bridge
A legacy remote recording solution bridging ISDN and internet connections
Overview
ISDN Bridge services allow voice actors to connect with studios still using legacy ISDN infrastructure by routing their internet-based audio signal through an ISDN gateway. This bridges the gap between modern IP-based tools and older studio equipment.
Voice actors connect from their home studio using Source Connect or a similar IP tool, and the bridge service translates the signal to ISDN format for the receiving studio. This preserves compatibility with studios that have not yet transitioned to IP.
How It Works
While ISDN technology is being phased out, some major studios and broadcasters still rely on it. Having ISDN Bridge capability can be a differentiator when competing for high-end clients.
Pricing varies by provider and usage, typically charged per session or as a monthly subscription. Costs can range from modest per-session fees to ongoing monthly plans.
Who Uses It
Worth considering only if you regularly work with clients whose studios still use ISDN. For most voice actors, Source Connect and similar IP tools cover all remote session needs without an ISDN bridge.
Pricing & Plans
ISDN Bridge pricing varies significantly by provider and usage model. Per-session fees from bridge services typically range from $25 to $75 per session depending on the duration and provider, while monthly subscription plans from dedicated ISDN bridge companies can range from $50 to $200 per month for unlimited usage. Some Source Connect Pro users can access ISDN bridge functionality through the Source Elements ecosystem at no additional cost beyond their existing subscription, though configuration can be complex. The cost of maintaining legacy ISDN lines directly — which some voice actors and studios still do — runs approximately $200 to $500 per month depending on the telecommunications provider and region, making bridge services dramatically more cost-effective for talent who only occasionally need ISDN compatibility. International ISDN bridge connections may incur additional fees depending on the routing required and the geographic distance between the IP and ISDN endpoints. The declining demand for ISDN services means pricing structures may change as providers adjust to the shrinking market, and some bridge services have already discontinued operations as the technology becomes obsolete.
Pros & Cons
What's Great
ISDN Bridge capability allows you to accept high-end session work from studios and broadcasters that have not yet completed their transition to IP-based recording infrastructure, ensuring you do not lose opportunities simply because of a technology mismatch. Some of the most prestigious and highest-paying voiceover clients — including major broadcast networks, European broadcasters, and established advertising agencies — maintained ISDN systems longer than smaller operations, meaning ISDN bridge access can connect you to premium work. The bridge approach lets you benefit from the convenience and cost savings of an IP-based home studio while maintaining backward compatibility with legacy infrastructure, providing the best of both worlds without requiring you to install and maintain your own ISDN line. Having ISDN bridge capability listed on your technical specifications signals to agents and studios that you are a well-equipped professional prepared for any session configuration, which can be a competitive advantage when casting directors are choosing between otherwise equally qualified talent. The technology is straightforward in practice — you connect through your existing Source Connect or IP tool, and the bridge service handles the protocol translation transparently, so the experience on your end is nearly identical to a standard IP session.
What Could Be Better
ISDN technology is actively being phased out worldwide, with telecommunications providers discontinuing ISDN lines in market after market, making any investment in ISDN-related capabilities an investment in a declining technology with a limited remaining lifespan. The number of studios that still require ISDN connectivity is shrinking rapidly, and many voice actors report that they have not received a single ISDN-specific session request in years, calling into question the practical value of maintaining bridge access. Bridge connections introduce an additional point of failure in the recording chain — if the bridge service experiences downtime or technical issues, the session cannot proceed, adding a layer of fragility that pure IP connections avoid. Audio quality through an ISDN bridge can be slightly degraded compared to a direct IP connection, as the signal undergoes additional encoding and decoding steps during the protocol translation process. The cost of bridge services, while lower than maintaining a dedicated ISDN line, still represents an ongoing expense for a capability that is used less and less frequently as the industry completes its transition to IP. The complexity of configuring and testing ISDN bridge connections can consume valuable time, and troubleshooting bridge-specific issues requires technical knowledge that most voice actors do not possess.
Our Recommendation
ISDN Bridge services are only recommended for professional voice actors who have confirmed, recurring need to connect with studios that specifically require ISDN compatibility — if you are not currently being asked for ISDN capability, there is no reason to invest in bridge access. Voice actors who work primarily with major broadcast networks, European studios, or established advertising agencies that are known to maintain legacy ISDN infrastructure should investigate bridge options as a practical necessity for accessing this specific tier of work. For the vast majority of voice actors, Source Connect, ipDTL, Cleanfeed, and other IP-based tools cover all remote session needs without any ISDN involvement, and the technology should not be a concern when building your home studio. If an ISDN-specific session request does arise unexpectedly, most bridge services can be set up on short notice for a per-session fee, eliminating the need for ongoing subscriptions. New voice actors entering the industry in 2025 can safely ignore ISDN technology entirely, as the transition to IP is functionally complete in most markets.
Pro Tips
If you do need ISDN bridge capability, test the connection thoroughly with your specific bridge provider before your first live client session, as bridge-related technical issues are particularly difficult to troubleshoot under the time pressure of a scheduled recording session. Maintain a list of two or three bridge service providers so you have backup options if your primary provider experiences downtime during a scheduled ISDN session, as bridge service reliability varies and having alternatives prevents session cancellations. Ask the requesting studio or client exactly what ISDN codec and connection parameters they require, as different ISDN implementations use different codecs and bitrates that must match between the sender and receiver for successful connection. Keep your Source Connect or IP recording tool updated to the latest version, as bridge compatibility can depend on specific software versions and protocol implementations. When quoting for sessions that require ISDN bridge access, factor the bridge service fee into your session rate rather than absorbing it as an overhead cost, as the client's infrastructure requirement is creating the additional expense and should be reflected in the project budget.