Last year, he participated in a new campus network project, which went from infrastructure to the campus-based WiFi network billing system and followed it for almost six months. The pedals that were stepped on throughout the process were technical, process and communication issues. This article was not intended to be a programme introduction, but simply to explain what really happened, and perhaps there is some value in referring to those who are going to do similar projects later on.
The new campus project is different from the renovation project.
Many of the teams who have been used to remodeling old campuses, and when they get to the new campus project, there is a miscalculation: they feel that the new campus is better because it's clean from scratch without historical baggage. That's only half the correct diagnosis.
The new campus has no historical baggage, but no historical experience. For five or six years, the old school district is running a bad signal, which building is particularly concentrated on the Internet, and which equipment is liable to be in trouble.——And these are in people's minds. There's nothing in the new campus, and you have to use drawings and theoretical designs to verify that design is reasonable when users come in.
Another difference is that the project was a cross-cutting process. The new campus was built during the same period with a lot of work, with weak power, power, fire protection, and renovations, and various engineering teams taking time and working hours. When network equipment entered the field, it was possible that the engine room had not yet reached the stage; when AP was installed, the ceiling was still unenclosed; at the time of testing, the user was not present and could not simulate the true height and development.
The pits where the billing system is connected
The time-line planning of the billing system is one of the most problematic points in the new campus project."Compressing test time, pre-lined"。
The system is not just online to install software, but also to have a set of parameters. It has behind it: initialization of accounts, set-up, charging channels, interface with the school finance system (if any), user training, web administrator operating training. Each of these things takes time, and compressing test times means that they either go through the process but their quality is compromised or skips directly, until users come in and fix the problem.
The case we have encountered in this project is that the charge system's replenishment is approved for the school finance system, and the interface file was available two weeks before the start of the school. It is almost impossible to complete the interface, test it, and access it within two weeks. The last option is to go down to the line first, to record it manually by the manager, to run through the first month of the school and then to push the interface. This temporary program has a real strain on its transport, and managers are about to collapse with hundreds of charging records every day.
The lesson is that the back-line plans of the system are to be planned independently of the civil construction period, and not as a result of delays in the construction of the system. In particular, financial matching, charging channels, etc., provide for cross-sectoral coordination, start up early, with sufficient time for communication and approval.
The web-top design is out of touch with the billing requirements.
Network planning for new campuses is usually dominated by network engineers who are concerned with topping stability, equipment selection, bandwidth redundancy. The billing system is concerned with authentication methods, strategy delivery, user segregation.
The most typical example is the selection of certification methods. In the top-down planned by network engineers, some buildings have gone PPOE dialing, others have gone Web Certification (Portal) and some teaching rooms have gone 802.1X. These three types of authentications are very different for access to the system. If a billing system is not involved at the planning stage, it will be discovered that there is no uniformity in the way certification is delivered, either ad hoc modifications or systems are being modified to fit up significantly.
We have encountered a specific situation: the dormitory building has taken PPPoE, and the billing system is logically good for online users. But the teaching building has gone Web-certified, with two certification links in the dormitory and teaching buildings, and the same number is recognized as the same user aggregate flow, which requires cross-certification of user identification, which was not considered in the initial programme and later took an additional two weeks to complete it.
Relationship between AP coverage density and billing system load
The number of new campuses is often much higher than the old school complex, especially since accommodation buildings are now largely one per dormitory.
The problem is often underestimated at the planning stage. The usual logic is that schools have 1,000 students, and they plan for a system capacity of 1000 account-based units. But real online co-processing will be concentrated during the beginning of school and late self-study periods, with peaks likely reaching over 80% of total accounts, while all are certified in short time windows, and certification processing capabilities of the system are bottlenecks rather than storage capacity.
Another point that can be easily overlooked is that there are 4-8 students per dormitory in the accommodation building, each with 2-3 units and a 500-person dormitory building, while the number of online devices may exceed 3,000. If the billing system is authorized by account instead of equipment, the logic involved in multi-equipment binding should be clearly thought out; if it is charged by equipment, the frequency of fitting up the checkrooms at the account number and MAC address will keep pace with the pace of equipment switching to pupils.
Initialization of data sources for the WiFi network billing system on campus
The new campus is connected to a system that will initialize thousands or tens of thousands of accounts. Where do you get the data?
Ideally: the teaching service provides complete gradation data, formatting specifications, field matching and direct import of a billing system. The reality is often that the teaching service ' s data are in another system, in an Excel (the field name is Chinese and there are consolidated cells) with a large number of irregular data, such as cell numbers 11 but space sizes, ID numbers with capital letters O and 0.
The data cleansing thing is often considered a project."It's nothing."But the time spent is quite long. We once met a school's export data, and class fields were not uniform across the school."IT 2nd class"There are some."Information 2"There are some."Letter 2") There are also a lot of anomalies in the matching rules for automatic import, and it is only by hand that the matching is done.
It is recommended that the criteria for data delivery be clarified at the project contract stage: what form of data is provided by schools, how fields are defined, and who will take responsibility for cleaning. Otherwise this workload falls on the implementation team in silence before the busiest hours of school.
A core issue in the testing phase: no real users
The new campus is only tested by simulation before it's occupied. But the simulation test has a natural limit: you don't know what real users do.
We've seen several tests."Pass."The scene of the problem is:
The first is that the authentication page has rendered abnormally on certain types of machines. The tests are conducted using standard Andre and iOS, with old ones from years ago used by students after being online, and the redirectional logic of Portal pages triggers browser compatibility problems, authenticates white screens, and students think the network is broken and they have a lot of barriers.
Second, the timing of the fee deduction.→Online→Disconnect→Settlement, no problem. It is found that some students’ equipment will remain open at the back of the line for long periods of time and at low speed, with traffic being cut off from one day and student complaints being miscounted.
Third, the authentication pressure is sent simultaneously. Ten devices are certified at the time of testing, pass; the power cut-off network is disabled at 10 p.m. on line, hundreds of people are certified at the same time, system response is overtime, certification fails, and a barrier is created. Such stress tests need to be designed and not covered by hand-on.
Three months after the new campus is online: the most vulnerable time window for a team of drivers
The first three months of the new campus's official opening are the most stressful phase of the project.——The problems have come in at the same time.
This phase requires a clear division of labour: first-line feedback for impairments, second-line system screening, third-line support for manufacturers, and three levels of alignment that cannot be fully congested with the same individual. There is also a need to have fast problem documentation and classification mechanisms that identify high frequency issues as priorities rather than being checked from scratch every time they are independent.
Network managers are often more intensive than expected at this stage.
The new campus network is a matter of connecting all parties involved from the planning stage, with network planning, billing programmes, initialization of accounts and financial interfaces, each of which has pits and is much more cost-effective than setting fire on line.