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Split Single HL7 TCP/IP Stream to Multiple Destinations

 

How to distribute inbound HL7 Messages to multiple destinations with minimal disruption to existing systems. You can see everything in this this article demonstrated on our YouTube channel in this video!

 

Scenario:
In our environment, we are receiving a feed of HL7 ADT (Admission, Discharge, Transfer) messages over TCP/IP from the hospital information system (HIS). These messages currently flow into our EMR listener on Port 31001.

Challenge
A new requirement has emerged:

• Replicate the existing ADT stream into 3 identical streams

• Deliver the same HL7 messages to the Radiology department on Port 6600

• Write the HL7 messages to a folder for import into a CORE HL7 SQL Schema Engine database

The complication? Our trading partner (the HIS), who supplies the ADT messages, is either unwilling or unable to provide multiple identical feeds. In many cases, this limitation comes down to costs or contractual restrictions, where vendors charge extra for maintaining additional feeds.

Requirements:

• Minimal disruption to existing interfaces

• The HIS TCP/IP sender should remain completely unaware of any changes

Solution in Four Steps

1. Switch the EMR Listener

   • Change the EMR listener to use Port 6101 instead of 31001.

2. Insert a CORE HL7 Postmaster

   • Deploy a lightweight postmaster service to listen on Port 31001 (the port originally used by the EMR).

   • The postmaster becomes the first receiver of the HIS messages.

3. Configure Three Destinations in the Postmaster:
   a. TCP/IP destination on Port 6600 for Radiology
   b. TCP/IP destination on Port 6101 for the EMR
   c. Windows folder destination for the CORE SQL Engine

4. Restart Services

   • Restart the EMR listener on its new port

   • Start the Postmaster to take over distribution duties

Outcome

With this approach, the only visible change is the EMR listener moving to a new port. The HIS sender continues to deliver to Port 31001 as before, unaware of any modifications.

The Postmaster transparently handles the replication and delivery of HL7 messages to all required destinations. This ensures:

• No additional cost or dependency on the trading partner

• A single, centralized distribution point for HL7 messages

• Flexibility to add more destinations in the future without involving the HIS team

✅ Takeaway
By inserting a Postmaster into the HL7 interface flow, healthcare organizations can overcome distribution limitations, meet new requirements quickly, and maintain minimal impact on existing systems.