Many think that the campus network WiFi billing system is a gateway, a page, and a student sweep. Indeed, it is a charge for WiFi from the student's cell phone to the cost, with four links certified, authorized, billed, audited, each of which has an independent technical logic.
Step 1: Terminal detection reoriented with Portal
Students turn on the WiFi list, and go to school with SSID, when the terminal is connected to AP and has access to an IP address on the intranet, but does not have access to it. The first step in the campus network's WiFi billing system is to detect this."Not certified", and redirects the terminal's HTTP to the authentication page. Technically, this is called the Captive Portal, usually by making transparent HTTP agents or DNS hijackings on the gateway level.
The common failure point of this link is that re-direction does not work. This may be because the terminal uses HTTPS sites for connection testing (e.g. Apple's Captive Network Aslistant), DNS parsing timeout, and the iptables rules on the gateway level are not properly configured. A good campus network WiFi will handle both HTTP and HTTPS initial connectivity tests to ensure that all types of terminals can pop out their authentication pages.
Step 2: Identification and RADIUS interaction
Students enter a study number and password on the Portal page, click on the login. The WiFi system of campus web transmits this certification request to the RADIFUS server backend. The RADIUS protocol is a factual standard in the field of network authentication, and the RFI system usually serves as a RADIUS client, sending user certificates to RADIUS Server for verification.
There is a question about architecture: RADIFUS Server is built on its own or re-use the unified identification platform that already exists in schools (e.g., LDAP, CAS). If schools have a single identity certification system, the campus network WiFi will support docking through RADIUS, rather than requiring students to register an alternative account number. This would allow for single entry, reduce the transportation burden and enhance student experience.
Step 3: Authorization to match web strategy
The WiFi system of the campus network requires access to this end after certification is adopted. Delegation of authority usually includes: allowed access to the web segments, bandwidth limits, time-to-flow quotas or flow quotas, and exports from its own operator.
For example, Student A handles a school telecommunications package with a monthly fee of $30 per month for 50 GB traffic. After certification, the campus network WiFi billing system needs to take student A's flow route from telecom to export and start recording traffic usage, automatically cutting off networks or speed limits when cumulatively reaching 50 GB. This strategy matches and is implemented in real time, directly determining the accuracy of the calculation costs.
Step 4: Real-time billing of participation in meetings management
The technology is usually implemented in two modes: the RADIUS-based billing report (Accounding-Request/Response) and the NetFlow/sFlow-based traffic collection.
The advantages of the RADIUS billing statements are natural integration with certification processes and mature protocols; the disadvantages are that they usually have long intervals (default 5-10 minutes) and insufficient real-time. NetFlow/sFlow has the advantage of having high flow accuracy to enable second-class coverage; the disadvantage is that additional collection and aggregation components are needed. A mature campus network WiFi will normally support both models, which managers can select or use according to their actual needs.
Step 5: Routeary strategy for multi-operator exports
In a multi-operator environment, the campus network WiFi billing system needs to determine which export link the terminal should take during the certification phase. Technically, this is usually done by strategic routers (PBRs) or SDN controllers. The operator information that students select on Portal pages will be entered into the user’s session log and the gateway level will make decisions based on this information.
A problem that can be overlooked here: the playground. Students move from a teaching building to a dormitory, and AP switching may trigger recertification. If the campus network WiFi does not handle the cruise scene correctly, there may be a jump in the operator's exit.——For example, the telecommunication exports selected by students suddenly become connected. This creates a bill error based on the operator’s fee model.
Step 6: Acknowledging technology realization
The technical principle is that, after students have successfully passed the Portal Certification for the first time, the campus network WiFi billing system records the MAC address of the terminal with its account number. When the MAC addresses are connected to the network, the system automatically completes the certification and the students do not feel that they are aware of the authentication process.
The technical challenge of unsenseed authentication is security. MAC addresses are easily forged and, if released by the MAC address alone, there is a risk of theft. So a mature campus network WiFi billing system would introduce additional verification mechanisms such as DHCP Office82 (recording physical location information for AP) to support judgement or MAC binding periods that require re-provalence over time.
Step 7: Log collection and audit compliance
The last part of the entire chain is log records. The WiFi system on campus requires a complete record of each user’s authentication log (who, when, where and in what manner) and web logs (which IPs are assigned, which target addresses are visited, how many traffics were used, how long). These logs are those that the Web Security Law requires to retain compliance data for at least six months.
The technology is achieved by balancing integrity and performance with log capture. Millions of logs are generated daily on a 10,000-sized campus network, which would put a great deal of pressure on the system if each one were written in real time. A mature campus web WiFi billing system uses antonymization, bulk submission, and layer storage strategies: thermal data storage high-speed for real-time search, cold data archiving to low-cost storage to meet compliance retention requirements.
Step 8: High availability and failure recovery
The high-availability design of the WiFi system on campus should cover all key components: main gearing for the gateway, RADIUS Server's main handler from a cluster, the database owner from a copy or group deployment, and redundancies in log storage. The time-over-switching proposal is within 30 seconds, an indicator that should be clearly included in the technical requirements when selecting a new set.