In a rare directly work-related turn of events. There have been some discussions by the VoIP team at Penn State regarding a problem with the Hook Switches on Cisco's IP telephones. Basically, the hook switch has been a mechanical contraption that sometimes gets stuck causing a telephone to not draw dial tone when you pick up the handset. Since I have used hook switch three times already, let me explain what it is. A hook switch is the little clicky button underneath the handset of your telephone that tells the phone you are either on- or off-hook.
Failure of the hook switch is a Cisco engineering problem. I mentioned above that this problem sometimes occurs. Penn State has deployed over 12,000 Cisco IP telephones at University Park, and of those 12,000 approximately 150 have experienced this hook switch failure. Conservatively, that is a 1.25% failure rate on these devices related to this feature. Cisco has published information directly related to this issue in the Tech Notes Article ID 45283. In the introduction of this notice, Cisco points out that an industry standard acceptable failure rate is 4%.
Cisco has made an attempt to redesign this component with their new devices the 7942G and 7962G IP phonesets. We just got a few of the new phones to take apart and break...er...um...test. :) Our colleagues at Brandeis University have already beaten us to taking one apart. See their NetSys Blog for more details and a couple pictures. From here, we need to determine if the new potential bugs in phone code will be less than the below average failure rates. If you are a customer, what do you think about new phones?
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