11.6. When, Not if, You Have Problems...
Each manufacturer of Voice over IP products, be they open or proprietary, has a certain amount of software and firmware code to maintain. Supporting Asterisk's development is a developer community with a mountain of C source code undergoing constant revisions. Cisco has a core development team for Call Manager, a firmware team that works on the IP phones, a developer staff for Call Manager Express, and an open source development coordinator . Because your VoIP network is made of software, it's only as good as the software that runs it. At some point, through diligent troubleshooting, you may pick up what you suspect is a bug.
For open source projects like Asterisk and VOCAL, the odds are good that another user has also noted the bug. The odds are also good that the bug has already been fixed. Then, it's just a matter of downloading the correct source code revision, compiling, and installing the revised distribution. Visit these sites to sign up for mailing lists where you can monitor the status of bug fixes and report bug- related issues and get general troubleshooting problems:
Commercial systems, like CallManager, Avaya's Media Servers, Nortel Meridian, Shortel's IP-enabled PBXs, and others, have the traditional commercial approach to bug catching. When enough customers complain, the development team ups the priority of a certain fix and then the company releases a patch. You, the user, download the patch to your PBX, reset your system during off-hours, and (usually) the problem is resolved.
Though a tech-head might prefer the freewheeling open source community's quickness in bug fixing, most IP telephone adopters go the commercial route for software maintenance. Either way, the system administrator should report any bugs encountered to her system's development community. After all, as the old saying goes, it's the squeaky wheel that gets the grease.