The electronic government department of the State of Wisconsin conducted a field trial of IP-Centrex, based on Lucent's iMerge product, in conjunction with SBC Communications, in late 2001. The state is a very large Centrex customer, with well over 60,000 lines in state offices, universities, and local agencies, such as county and city governments.
The Centrex features were derived from a 5ESS CO switch in Lisle, Illinois, and carried 145 miles over a T1 link to the state's offices in Madison, using the configuration shown in Figure 1. The equipment in Lisle was shared with the much larger IP-Centrex pilot test at Lucent's own campus in Naperville, Illinois (which is described below).
This project in Madison lasted for 90 days and involved only 11 users, based on a preexisting 10/100 Mbps LAN, which has approximately 100 users on each Ethernet switch. Unidata IW200 IP phone sets were used for this trial. These telephones employ the H.323 protocol, with a G.711 codec, echo cancellation, an internal hub, and local ac power supply.
The trial's coordinator concluded that the successes of this project were that all the features of Centrex, including 911 calls and voice mail, continued to work, there was full integration into the State's five-digit dialing scheme, and there were no apparent issues with the LAN.
A number of problems were identified, such as intermittent voice clipping and fading, frequent echoing and excessive background noise in the sets, infrequently dropped calls, and two complete service outages. Users also complained about a slight delay in obtaining dialtone and poor telephone set ergonomics.
The conclusions from this small trial were that home-based workers and "road-warriors" are most likely to benefit from IP-Centrex, while no applications have yet been written for the IP phones.
SBC Communications deployed an ambitious trial of IP-Centrex, jointly with Lucent, at that company's new technology center at Naperville, Illinois, in the spring of 2001. This live network trial served more than 1,600 product development, design, and test personnel through an iMerge Centrex Feature Gateway linked to the 5ESS central office system, which also provides digital Centrex service to 10,000 employees on the same industrial campus.
A 2-month trial of IP-Centrex was conducted in the spring of 2002 at the University of Toronto (UTO), in partnership with Bell Canada and Nortel Networks. The university rents about 12,000 Centrex lines for its 200 buildings, spread over four campuses, with single wire center service for each campus. All intercampus calling is done over the PSTN, with 10-digit dialing within and between two area codes, as all the sites are in one extended local calling area. UTO has been a digital Centrex customer since 1986 and currently has a 5-year contract, at $14.35 per month per line.
For the last 5 years the university has subscribed to the Station Configuration Management service, which allows a customer's own telecom personnel to implement some moves, additions, or change orders in real time. However, the more complex change requests need the participation of Bell's technicians in the CO, where their turnaround time for work on one to five sets is up to 1 week. It turns out that approximately 75% of orders need at least some action by the telco, so the telecommunications manager sends the whole request to Bell, since the university would not save any money by doing part of the job and splitting responsibility for a work order increases the possibility of errors. In other words, UTO's telecom analysts can only do about 25% of the MAC requests that are received from their users in the legacy Centrex environment.
UTO owns three Avaya/Octel voice mail systems, with one unit being installed at each of its main campuses, and has a total of 6,800 voice mailboxes. Six thousand mailboxes are used for the large downtown campus, while the Aerospace Studies Institute, in northern Toronto, rents 100 voice mailboxes from the telco's call manager service. There are some 80 bulletin board services also based on the Avaya systems, which vary greatly in size and usage.
A three-position switchboard continues to be ample to handle calls through the main listed number, which is first answered by a recorded announcement, with option 1 going to the operator and option 2 to the main menu.
Bell Canada has provided a stable, dedicated team of support people to UTO, and this has led to a QoS for legacy Centrex that cannot be beaten.
Thirty users, located in several buildings on the downtown Toronto campus, participated in the IP-Centrex trial. The service was delivered over a T1 link from the same DMS-100 system that provides legacy Centrex. These users included administrators, academics, and IT personnel. Each participant had a Nortel i2004 phone plus a SIP Client package in the desktop PC. These people have found it hard to adapt to the softphone and much prefer to use the IP telephone set. Voice quality over IP-Centrex was very good when calling within the trial group or to other Centrex phones in the university. The most significant quality difference was on some calls with cell phones, when "clipping" sometimes occurred. Compared with legacy Centrex, there was also some loss of quality on conference calls; the audio degraded as more participants were added.
Responsibility for data networks at UTO is split between the central IT department, which looks after the optical fiber backbone between buildings, and the department responsible for a specific building, which controls the LANs inside that building. All LANs deliver switched Fast Ethernet to each desktop, but the quality of local network management differs widely.
Within this university environment there is not much call for the networked applications that are offered by IP-Centrex. No one is asking for UM and there are no requirements for CRM. The ability to set up a short-term, virtual call center may be helpful for a few class projects and the potential easily to adjust the number of lines to meet seasonal demand in student residences may have some value.
The real interest in this case is how IP-Centrex will be tariffed. Because the switching is being done in customer-owned equipment, the rates should be lower than with legacy Centrex, but there is not yet any information available as to how much less the costs will actually be. At the very least, there is hope that the implementation of IP-Centrex may allow the university to increase its share of in-house MACs from one-quarter to three-quarters of the total.
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