we described how software development outside the networking realm benefits greatly from the readily available open source software.
For example, application server frameworks provide platforms that allow software developers to reuse code provided by those common frameworks and therefore to concentrate on solving domain-specific problems. Without the ability to leverage software functionality in this manner, each vendor would have to develop, test, and maintain large amounts of redundant code.
With the closed networking
environment that is prevalent today, little such leverage is available, and consequently each vendor must implement all of the common functionality required by their devices. Common network functionality and protocols must be developed by every device vendor. This clearly increases the costs attributable to software development.