"One secretary had gone to use the copier outside the office, the other had gone down the hall to find a teacher, and there was nobody there," he said. "So it took a couple of minutes until he was able to get ahold of somebody to then call for help. What if that had been a student, and what if it had been a more serious injury? A walkie-talkie is a pretty limited device if there's nobody on the other end to answer it."
Now security guards, equipped with wireless VoIP phones, can simply dial 911 in an emergency. Auker said the system has been set up so that if a 911 call is made, it is specially routed through the school's phone line so the call will report the proper address for E-911 purposes, rather than sending the call over the districtwide VoIP network, which would report the district's business office address. Non-911 calls are routed across the VoIP network and back to fiber-optic lines at the board office.
Mobile phones for each teacher will be rolled out over the next 10 to 15 years as part of planned construction projects in the district, said Auker. Giving teachers communications devices that allow on-campus mobility is practical, he said, because teachers sometimes must accompany classes to places outside the classroom, such as the library, lunchroom or playground.
Security is another reason teachers will benefit from the ability to move around with their phones.
"If something happened -- there's someone running around the school with a gun or some other problem like that -- it would be better for the teacher to have a wireless phone because they don't want to be standing by the door speaking on a regular wired phone."
The district also plans to expand the Wi-Fi networks to areas around the school, such as parking lots or bus loading areas, Auker said. Currently he said staff must rely on signals that bleed through the wall of the building when they are in outdoor areas, and they sometimes lose connectivity.
"When we first put in the wireless network, we didn't actually take into account how often they would really want those phones to work outside." Auker said the need for outdoor signals will be addressed in future construction projects.
The wireless VoIP phones are comparable to landline phones in terms of quality, Auker noted. "There's really no difference. Because it's digital, it is not picking up the same type of interference and things you get with a cell transmission."
The network must be properly set up to support wireless VoIP phones, however, to produce such quality. "That has to be the No. 1 piece of data that gets routed through your network because there can't be any lags or slowdowns because of a lot of data traffic."
According to vice president and general manager for Cisco's government systems unit, Ed Carney, e-mails, large files, and so on typically are sent over a network in bursts. So a lot of data may be sent across the network at once, he said, and then there could be nothing for a second.
"With voice, you've got different QoS considerations where you're sending a steady stream of data, and you need to be sure it all arrives there around the same amount of time," Carney said.
Quality of service requirements are set up using software that runs on the routers and switches, which Auker compared with traffic cops at busy intersections. "If data comes through and it's labeled as 'voice,' that's like an ambulance coming through the intersection. Everybody else has to stop."
While the network works well for on-site staff such as custodians and security staff, Auker said