The FAA has introduced NextGen, an ambitious initiative designed to transform the entire U.S. National Airspace System (NAS). One of the FAA’s early implementations has occurred in two flight-critical NAS subsystems: NADIN and WMSCR. Soon, both of these subsystems will only be accessible via the FAA’s new interface, known as the Common Message Handling Protocol (CMHP).

As an example, flight plan filing now must use CMHP over TCP/IP to interface to the FAA’s National Airspace Data Interchange Networks (NADIN). In turn, NADIN interfaces with the global Aeronautical Fixed Telecommunications Network (AFTN). AFTN access not only allows aviation entities to manage global flight plans but also a multitude of other flight critical messaging including slot requests, catering requests, overfly permits, etc.

In a particularly notable advancement, NextGen also makes real-time weather data more accessible to decision makers via its new CMHP interface. This new weather stream gives more accurate real-time information when dealing with forecasts and changes in unpredicted weather. The FAA’s weather data and Notices to Airmen (NOTAMs) are available through the Weather Message Switching Center Replacement (WMSCR).

Leveraging over a century of aviation data communications expertise, AvFinity offers NADIN CONNECT loaded on AvFinity AEON AIRS as a plug-and- play appliance. The NADIN CONNECT software operating on a Cisco blade server represents a highly scalable, extremely cost-effective solution that provides flexibility, reliability and robustness for your data communications center in addition to NextGen capabilities.

Realizing NextGen Benefits

In order to benefit from the NextGen enhancements to NADIN and WMSCR, airlines now must connect directly to the FAA using resident software that can translate CMHP. But the roadmap to switching over to CMHP can be long and arduous if the solution is built in-house.
Becoming CMHP-ready requires an airline to:

  • Research the CMHP library, architect a solution, and write a CMHP application that integrates into the airline’s back-end systems and communicates via CMHP.
  • Test the application internally.
  • Test the application with the FAA at three levels: CMHP conformance; interoperability testing; and maintenance activity in the case of degraded operation.

AvFinity CMHP NADIN Connect Architecture AdvantagesOnly after successful testing in all three levels can an airline connect to NADIN and WMSCR under the new NextGen protocol. From start to finish, the process may take three years or more and occupy the full attention of two or more internal or outsourced developers. By comparison, airlines can benefit from NextGen in a matter of months with the FAA-tested AvFinity NADIN CONNECT™ on AvFinity’s AEON AIRS™, a solution designed to speed airlines’ adoption of the FAA’s NextGen digital communications advancements. The AvFinity NADIN CONNECT provides rapid benefits from NextGen efficiencies and a reduction in airlines’ development time for a CMHP solution by as much as 24 months.  The appliance enables airlines to connect directly to the FAA for NADIN/ AFTN access and WMSCR and NOTAMs, passing data over TCP/IP through the added layer of the FAA’s secure Common Message Handling Protocol (CMHP).



By using AvFinity’s NADIN CONNECT, airlines realize multiple benefits through more rapid access to the promise of NextGen:

  • Compress the connection time via CMHP to NADIN/AFTN and WMSCR. NADIN Connect on AIRS means airlines drop costly, inefficient legacy X.25 technology and embrace the speed and simplicity of a TCP/IP connection.
  • Compress testing phases through software that has been approved and tested by the FAA. AvFinity’s NADIN CONNECT eliminates two-thirds of the mandatory FAA testing for internally produced applications versus our outsourced API products.
  • Option to use CMHP as an AvFinity managed service. The AvFinity Cloud will manage alerts to ensure key personnel receive flight-critical information via a web interface, email and/or mobile phone.
  • Acquire experts for remaining tests. AvFinity’s experts, with experience in all FAA CMHP tests, can help airlines through the necessary trials in order to get certified to connect via CMHP. This feature again compresses time to effective use of NextGen.
  • Benefit from software that runs simply and hassle-free. AvFinity’s NADIN CONNECT works as expected, perfectly and invisibly on the AvFinity AIRS appliance.
  • Save time and eliminate development costs. Researching the FAA’s library followed by writing an internal API to connect via CMHP will take two to three years (not including testing). AvFinity’s NADIN CONNECT is available today.
  • Seamless updates. AvFinity will provide revised versions whenever the FAA releases a newer version, which means your airline will always be up to date.
  • Keep familiar processes. The AIRS software with the NADIN CONNECT appliance integrates into an airline’s backend to replace existing connectivity. This feature allows your systems to maintain the same flight plan and weather procedures as usual.
  • Expand as NextGen grows. AvFinity is authorized to pass on newer versions of the FAA-provided CMHP library, so NADIN CONNECT will work with future FAA products reliant on the agency’s same proprietary message protocol.

Technical Specs

  1. Event-driven TCP/IP implementation to manage the CMHP library with lower CPU utilization. The AvFinity solution uses the port driver to notify the application versus polling the port.
  2. Patented scripting engine to handle front and back-end integration.
  3. Easy alteration of configurable parameters via a conf/ini file. An optional web interface for configuring is available.
  4. Robust logging system for monitoring CMHP using rotatable logs. The API rolls the log at 512KB up to three logs.
  5. CMHP alert mechanism to the web interface, email or SMS in case of an outage.
  6. Multiple instance capability using configurable parameters for handling multiple FAA products e.g., FAA requires one CMHP process for WMSCR and one for NADIN.