I recently discussed an interesting issue with a long term client:  Why should we pay recurring royalty fees to a commercial software vendor when we could replace the commercial software subsystem used in our product with free open-source software?

A previous post, Commercial or Open-Source Software?  Lowering the Cost of SNMP Applications Development, reviewed the “build or buy” analysis from a green fields perspective, when the initial development of an SNMP application is the focus and concern.

But what about a long time fielded product?   Sure it is always good to eliminate a recurring expense, but what is the real cost to replace working SNMP Agent code with new code based upon open-source software?

Are you prepared for substantial development costs?  An SNMP Agent development kit, commercial or open-source,  provides the core agent functions and an API for implementing the MIB modules appropriate to an internet enabled device or service.  Different development kits, different APIs.

Be prepared to port or migrate your existing MIB code to use the new API.  The ‘method’ routines comprise the code that is generated by the MIB compiler and interface with the developers’ kit API.   If the existing code has separate  ‘instrumentation’ routines, the code for retrieving and setting actual system dependent values, then most or all of the instrumentation code can be ported more easily than instrumentation code that was originally placed directly into the generated method code.

If  we are talking about an embedded, memory constrained device, then we need to consider any additional memory budget required by the open-source software.  Will a hardware change be required to increase flash memory capacity to accommodate the new code?  How does the potential recurring cost of this additional hardware part compare with the existing recurring cost for software royalties?  If the costs are similar, the obvious decision is to continue to pay royalties.

Let us be aware that changing a software subsystem within a fielded product will incur additional costs for software quality assurance activities as well as incur additional costs for ongoing maintenance to remedy software defects reported by QA and customers.

As we add up the costs necessary to move to “free” open-source software, we can make a quantifiable comparison:  How many units of royalty will it take before we break even on new development and maintenance costs?  For an established product line, we are able to convert the count of units into a time duration representing a payback period.  Any payback period longer than five to seven years is probably not attractive enough to make the switch to open-source from commercial software.

One final point to consider: Is it a viable alternative to approach the commercial software vendor and buy out the recurring royalties?  A buy out may be considerably less than the estimated cost of converting to open-source software.

Over the past 20+ years I have gained experience with the best commercial and open-source SNMP developers’ kits.  Please contact me and start a conversation about your project needs.  And, be sure to use Ellison Software Consulting to bring value to your SNMP enabled product designs!