INTEROPERABILITY

For all the promise of interoperability, TR-069 implementations still have a way to go. While the specification itself is fairly well written, there is room for interpretation and error during the implementation. For example, there is a typo in the specification where a common word, used to define a field, is misspelled. Does the vendor take the specification at its literal meaning, or does the vendor correct the spelling error? Both approaches have been taken, resulting in incompatibilities.

Another issue is the SOAP implementation. SOAP, Simple Object Access Protocol, is the communications protocol mandated by TR-069. The specification further mandates that all communications between the CPE (client) and ACS (server) are done via a persistent, bi-directional connection. However SOAP was designed for transitory, one-way communications where the roles of client and server are clearly defined. By requiring a persistent, bi-directional connection, TR-069 is switching these roles during communications, something SOAP wasn't designed to do and introducing complexity to a "simple" protocol.

As a result of this shift, developers of TR-069 software are required to develop their own SOAP implementation. This has caused problems on how different SOAP implementations interpret the SOAP messages. Normally the handling functions are defined during product development and the rest is automatic. However, in the current specification it is necessary for the SOAP to be generated manually; a process highly prone to errors.

The Dimark client also includes a full SOAP Parser to ensure compliance with the standard and complete interoperability. Don't be fooled by others who try to decrease the RAM and Flash footprint with a partial, or hard-coded SOAP implementation; those "savings" come at the high cost of poor interoperability, a lack of flexibility and the resulting lost deployments.