Like many public institutions, the university had for many years used an ISDN telecom system from Siemens that became totally overloaded over time. Then, in 2005, not only did the service agreement expire, but it also became clear that a bigger solution definitely needed to be planned for. Prompted by developments on the telecommunications market, university decision makers formulated their intent to switch to VoIP across the board the next time there was a telecom shift. "The old phone system was truly exhausted, down to the last connection," Celina recalls. "Whenever someone new came to start work at the university, it didn't matter who it was - there simply weren't any free ports left!" That meant only one thing: A replacement was needed, if possible one that was both cost-optimized and open to any and all kinds of further growth. 

The university team established a fundamental concept with a number of goals they aimed to accomplish: 

• An individual phone number for every member of the faculty and staffs
• Separate phone numbers for organizational units (dean's offices, chairs, etc.) 
• Phone numbers for telephones in corridors and lobby areas, elevators, seminar rooms, etc., and
• If possible, also separate phone numbers for every student on the campus, plus
• Growth options with as few limitations as possible  

The goal at the time was to connect over 3,500 telephones, which were also supposed to be able to provide multiple different IDs. "That's a big advantage of VoIP phones," Celina explains. "Because it's possible to set up different user accounts, faculty and staff members are completely free in terms of where they work. Using a personal PIN, anyone can log in at the workplace where they are at the time and have their personal phone settings available right away. On the other end, call recipients always see the phone numbers they are familiar with, and the name of the person calling. And the best thing about it is that we will shortly have this system working internationally as well, so for example, I could use my Würzburg ID to reach my colleagues at the computing center free of charge from Washington, D.C.!" Those are advantages that speak clearly in favor of the switch to VoIP. And when one also considers the costs that will be saved, for instance in the case of new buildings, where only one network is needed for both data and voice, the advantages of this technology become even clearer.

The result of the call for bids for the VoIP phones came as a pleasant surprise for everyone involved, because the university would be working with an "old friend." The winning bid was submitted by snom technology AG, based in Berlin, with its snom 370 model. Celina was very pleased with the convenient, easy-to-use snom 370. "If we're going to buy new phones, we should do so at as high a level as possible so that our end users can keep using them happily for a long time," he says, outlining his key principle for this step. 

Subsequently, the university and snom agreed on a number of different rollout dates on which the snom 370s would first be set up at individual workstations in parallel to the old phones. Just to be on the safe side, the computing center's staff had decided to have ISDN and VoIP running in parallel for a specific transitional period in order to be able to resolve any technical problems or initial difficulties faced by snom 370 users without pressure. "Configuring and integrating all 3,500 phones at once would have been far beyond our capacity," Celina explains. "But working by stages, we were able to ensure that whole institutes or whole buildings always went live on the network at the same time." The first 500 faculty and staff members were introduced to the new phones in September 2008. And the new phones from snom were well received, and quickly. After all, in combination with the self-configured Asterisk system, they offered some features that the old phones provided only with a huge amount of work and only to selected users - if at all - such as: 

• Voice mail 
• Call forwarding 
• Do not disturb (DND) function 
• Boss-secretary features 
• Speed dial numbers, call logs 
• Phone book connection, name selection 
• Configuration also via the website, and many more.   

These functions, combined with the excellent voice quality, ensured that the faculty and staff of the individual departments at the university got used to their new phones very quickly. In most cases, the new snom 370 had hardly been installed in its new place before it was quickly tried - and then became the phone of choice for permanent use. "This process, which went very well in all the departments, actually exceeded our expectations," Celina recalls. "In fact, we had expected some initial difficulties - both on the technical level and on the part of users. But with the Asterisk pbx and the snom 370, we had neither, which naturally saved us a lot of time and hassle. And that, in turn, led to the fact that instead of the 3,500 phones we had originally planned, we are now connecting more than 4,500!" 

While the option, highly valued by other users, of using network power to run the snom 370 (Power over Ethernet or PoE) was out of the question due to the fiber optics installed in the university's buildings, the snom 370 still had to prove its abilities under tougher conditions. For example, some devices have to work in three buildings connected via tunnels, i.e., buildings in which the network communications protocol is used as a means to transport data to an off-network server. In another case, the network is connected via WLAN, and amazingly, the snom 370 phones work with no problem even there. The only technical problems at present are caused by a few fax machines, which have to be connected via T38 because it is still necessary for them to be coupled to the old system. "Here, the university's reality is a little behind the VoIP world," Celina explains. "For us, most fax machines are still actual devices, and not software!" But the open standard means that even this problem is a temporary one at most. "If needed, we will install a small ISDN system just for our faxes as a transitional step," Celina adds.