Especially in the cellular wireless environment, if the billing system cannot be accurately differentiated“Unusual break”and“Real offline.”And the consequences are not usually functional, but rather...Disruption of accounts, state of drift and system instability。
A real mature billing system never took it.“Break”As a simple event.
One thing: 90% of the wireless environment is not broken.“Real offline.”
In the accommodation wireless environment, common sources of break wire include:
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AP Wandering Switch
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Wireless signals are rapidly declining.
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End-of-pipe power strategy
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System backstage hanged
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Local Links Dithering
In these cases, most break wires have three characteristics:
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Short duration
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Terminal reconnects quickly.
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The user remains subjectively active.“Use the net.”
If the campus network Authentication & Billing sees all these things as“Real offline.”The system will:
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Frequent termination of fee sessions
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Recreate fee instance
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Activate terminal occupancy anomaly
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Magnify system loads during peak periods
The first principle is therefore very clear:
Break ≠ Offline
II. A genuinely available system of accounting that is not dependent on“A signal.”
Low-mature systems, which judge offline, often rely on a single condition such as:
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Heart rate lost.
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Session Disconnected
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NAS Sideline Notification
This approach is almost invariably misjudged in the cellular wireless environment.
A mature campus network Authentication & Billing system, which determines abnormal break-off and actual offlines, usually usedMultidimensional condition combination determination。
III. The core determination logic of abnormal break-ups and actual disconnections
1. Introduction“Observation period”Not immediately.
When a break wire event is detected by the system, the mature billing system will not immediately perform the following actions:
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Termination charges
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Release terminal slots
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Write Offline Accounts
It's about entering one.Observation period status：
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Session Status Mark As“To be confirmed”
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Retention of costing context
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Pause instead of end charges
The observation period exists as the first line of defence to distinguish between abnormal break wires and actual decoupling.
2 Reconnection is one of the most important grounds for judgement.
The blogger says that the situation is not a good one.The abnormal break is almost always accompanied by a quick reconnection.。
The mature campus network Authentication & Billing system will judge:
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Whether to re-validate within the threshold time
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Whether or not from the same terminal feature
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Whether to restore the original context
If these conditions are met, the system will determine that the break is:
Unusual break → Sessions continue
The billing will not be interrupted and the accounts will not be split.
3 Flow and behavioral aids, not just certification status
In the real system, determine whether“Still using the network.”, cannot just see authentication status.
The mature systems are usually integrated:
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Have you got any traffic lately?
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Is the session still being forwarded?
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Is the session ageing timer due?
As long as there is an effective act, the system will not venture to conclude that it has actually been offline.
4 Time threshold is not fixed value, but a configuration policy
Different colleges, different dormitory environments.“Unusual”The definition is not identical.
Thus, the mature campus network Authentication & Billing system usually supports:
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The abnormal breakout determination time is configured
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Different threshold values for different user groups
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Differential strategies for access
That's how the billing system works.Fitting the real wireless environment to run instead of imposing uniform rules。
IV. ARRIVING DEEP-UP, THE COST SYSTEM REALLY“Pause”What's that?
A very critical, but often misunderstood point is that:
When the wire is off, it's not that the billing system has been suspended.“Account”But...“Billing forwards”。
During the abnormal break-off of the mature billing system:
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Retention of costing context
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No push time
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Do not release terminal places
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Do not generate new accounting records
Once a true de-link is confirmed, the complete off-line process will be implemented.
V. The determination of the conditions for de-linking is, on the contrary, more“Strict”
In mature systems,“Real offline.”The determination usually requires that several conditions be met, such as:
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No reconnection beyond maximum observation period
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No flow or session behaviour
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The session is aging.
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No subsequent certification request
Only when these conditions are fully met will the system:
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Examples of closing charges
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Write full accounts
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Release terminal slots
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Cleanup Session Resources
This.“I'd rather be slow than misjudged.”Design is the key to long-term stability.
VI. REAL OPERATION OF ANIMAL LIGHTS IN THE RADIO-OVERSIDE
Here are the abstractions of the true operating logic of anonymous universities.
Environmental conditions
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School students, about 30,000.
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The dorms are all wireless.
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"The evening peaks and the springs." > Twenty thousand.
Actual system performance
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You're in observation after you break the line.
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5–30 seconds of reconnection is considered to be an abnormal break.
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The billing is continuous and undisbursed.
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Terminals are not reoccupied
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No large number of requests for certification at the late peak
The user side almost cannot sense a break and the system side account remains continuous.
VII. WHY“Breaking the wire.”It's decided how long the billing system will run.
On the campus network Authentication & Billing system:
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How much function is not important.
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It's important to judge right.
Once the break wire is rough, the longer the system runs:
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The more the account data are broken
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The higher the cost of a carrier's bearing.
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The more likely it is to file a complaint.
Such problems are often not apparent at the very beginning of the line.
NatShell, in the 21st year of college, is a wireless form around dormitories.The most complex and less ideal real environment.The logic of the constant grinding system for determining abnormal break wires and actual offlines has culminated in the current stable, functional and value-added campus network NATSHEL_AUTH_BILLING product system.