A bug tracking system is a software application that is designed to help quality assurance and for programmers keep track of reported software bugs in their work. It may be regarded as a sort of issue tracking system.
Many bug-tracking systems, such as those used by most open source software projects, allow users to enter bug reports directly.
Other systems are used only internally in a company or organization doing software development. Typically bug tracking systems are integrated with other software project management applications. Having a bug tracking system is extremely valuable in software development, and they are used extensively by companies developing software products.
So Network based bug tracking system is actually nothing but just a internally (specific company's in-house bug tracking tool) integrated Software to track bugs.