Subscriber & Revenue Systems
The subscriber lifecycle — authenticate, meter, bill, collect, provision — is a chain of system handoffs, and revenue leaks at the handoffs, not in the middle.
Billing is not an accounting problem. It is a network-behaviour problem with an accounting interface.
01 — The Problem
A Subscriber Is Not a Row in a Database
A subscriber is a PPPoE session on a NAS, an accounting stream into RADIUS, a balance in a billing ledger, a payment arriving over a mobile-money rail, and a ticket history in a CRM. Those five views of the same customer are maintained by different systems — and every place they can disagree is a place revenue quietly disappears or service quietly degrades.
Across two decades inside ISP operations — from EdgeNet through InterSAT, KDN, BSS, and SkyTrend to HCS — the pattern we keep meeting is the same: the network does one thing, the billing system believes another, and nobody is reconciling the two until an auditor, an investor, or a cash-flow crisis forces the question.
This page describes how we approach that problem: make the ledger and the network agree, continuously and by design.
02 — Subscriber Stack
The Subscriber Stack, End to End
Four domains, one invariant: the state the network enforces must be the state the ledger records.
AAA & RADIUS Accounting Integrity
Authentication decides who gets on; accounting decides what you can prove afterwards.
What We Work On
- Authentication flow review — PPPoE (PAP/CHAP), hotspot MAC-auth, and portal logins
- CoA and Disconnect-Message behaviour: does suspension actually disconnect?
- Accounting completeness — Start, Interim, and Stop records that survive NAS reboots
- Interim-update intervals sized for prepaid enforcement, not vendor defaults
- FreeRADIUS and packaged OSS/BSS RADIUS stacks (Splynx-class platforms)
- RADIUS failover that fails safe instead of failing open
Why It Matters
- Usage records you can defend in a dispute or an audit
- Suspension and plan changes that take effect in seconds, not on next login
- No sessions the billing system has never heard of
PPPoE, IPoE & Hotspot Access Models
The access model determines how much subscriber control you get for free — and what you must rebuild if you change it.
What We Work On
- PPPoE session control as the enforcement backbone for prepaid and expiry-led plans
- IPoE/DHCP migration paths (Option 82, subscriber-aware BNG) without losing policy control
- Captive-portal and voucher authentication for hotspot estates
- MAC binding, device limits, and concurrent-session policy
- Speed-profile enforcement that matches what the plan actually sold
Why It Matters
- Prepaid enforcement that does not depend on manual intervention
- A migration story for FTTH growth instead of a control-plane surprise
- Hotspot access that is monetisable, not merely open
Billing–Network Alignment
The ledger and the NAS must tell the same story about every subscriber, every day.
What We Work On
- Plan catalogues reconciled against the speed profiles RADIUS actually returns
- Suspension, expiry, and proration logic verified against live session state
- Routine accounting-to-invoice reconciliation as an operational job, not a forensic one
- CRM and ticketing integration so support sees session and payment state on one screen
- Revenue-leakage indicators instrumented as recurring reports, not one-off queries
Why It Matters
- Billing disputes answered with evidence instead of apology
- Leakage surfaced in days, not discovered at year-end
- Support calls resolved without swivel-chairing between four systems
Mobile-Money Settlement Integrity
When M-Pesa, Airtel Money, and MoMo are the primary rail, the payment callback is a production system — and must be engineered like one.
What We Work On
- STK push and paybill C2B flows treated as untrusted, retried, asynchronous input
- Idempotent callback handling keyed on receipt and request identifiers
- Status-query fallback for callbacks that never arrive
- Paybill-statement-to-ledger reconciliation on a fixed cadence
- Payment-triggered activation: money in, CoA out, no human in the loop
Why It Matters
- No double-credited payments, no paid-but-offline subscribers
- A settlement trail that matches the bank and the operator statement
- Cash collection that scales without adding back-office headcount
03 — Money Path
Follow the Shilling Through the Stack
Every revenue defect we find lives at a handoff. This is the path a payment takes — and every arrow is a place it can leak.
SubscriberMobile-money rail
STK push or paybill payment initiated
Mobile-money railBilling ledger
Callback posts once — idempotent, or double-credited
Billing ledgerRADIUS / NAS
Activation or CoA fires — or the paid subscriber stays offline
RADIUS / NASBilling ledger
Accounting records close the loop on actual usage
Billing ledgerCRM & ticketing
Payment and session state visible to whoever answers the phone
When this loop runs cleanly, provisioning is automatic, disputes are rare, and the month-end numbers reconcile themselves.
04 — Leakage
Where Subscriber Revenue Actually Leaks
Leakage is rarely theft. It is almost always a systems defect nobody owns.
Authentication Gaps
- Expired accounts that still authenticate
- Shared credentials and cloned MAC addresses on hotspots
- Staff and test accounts left enabled indefinitely
- NAS devices accepting sessions the AAA layer never sees
Accounting Gaps
- Missing Stop records after NAS reboots or link flaps
- Interim updates too sparse to enforce prepaid quotas
- Sessions that survive suspension because CoA never fired
- Orphan sessions billed to nobody
Settlement Gaps
- Duplicate credits from replayed payment callbacks
- Callbacks that never arrived and were never re-queried
- Paybill statement lines with no matching ledger entry
- “Activate now, reconcile later” manual workflows that never reconcile
Lifecycle Gaps
- Speed profiles more generous than the plan that was sold
- Proration and expiry logic that disagrees with session state
- Churned subscribers still provisioned on the network
- Discounts and overrides with no audit trail
The control is the same in every case: reconcile what the network says happened against what the ledger says was paid — routinely, not forensically.
05 — Operations
Beyond the Ledger: Running the Subscriber Operation
Wi-Fi Hotspot Monetisation
Hotspot estates are a genuine revenue line when run on voucher economics: bundle design, splash-page-to-purchase conversion, payment-to-access latency, and voucher lifecycle tracking. We treat a hotspot as a small prepaid ISP — same AAA, same settlement discipline, shorter sessions.
CRM & Ticketing Integration
At DSI in the DRC we deployed ticketing and monitoring systems that improved both internal and customer-facing operations. The lesson carries everywhere: an agent who can see session state, payment history, and open tickets on one screen resolves the call; an agent who cannot, escalates it.
Provisioning Automation
Ledger-driven provisioning is the goal state: a payment event activates service, an expiry event suspends it, and no step depends on someone noticing a message and clicking a button. Orchestrating that flow across billing, RADIUS, and the NAS is where manual back-office cost actually disappears.
Churn Economics
In prepaid markets churn is silent — subscribers do not cancel, they simply fail to renew. That makes the expiry-day experience the retention lever: renewal friction, payment-to-reactivation delay, and outage history around expiry are measurable, and each one moves the renewal rate.
06 — Phase 0 Signals
Signals We Look For in a Phase 0 Review
PPPoE and hotspot authentication flows, AAA and RADIUS accounting integrity, billing-system alignment, and revenue-leakage risk indicators are standing coverage areas of our Phase 0 review. These are the findings that recur:
- A measurable share of sessions with no accounting Stop record
- Payments credited more than once from repeated settlement callbacks
- Suspended or expired subscribers holding live sessions
- Paybill statement totals that do not match the billing ledger
- Activation workflows that run through a phone and a spreadsheet
- Speed profiles in RADIUS that exceed the plans actually sold
Each of these is a measurable, fixable systems defect — not a cost of doing business.
PPPoE refuses to retire in African prepaid markets for a good reason: session-based enforcement with CoA is still the cheapest way to make expiry actually mean expiry, and the operators moving to IPoE for FTTH scale are having to rebuild that control with Option 82 and subscriber-aware BNGs rather than getting it for free. The other 2026 shift is cultural: the better operators now treat the mobile-money callback — not the STK response — as the source of truth, run status-query sweeps for the callbacks that never came, and manage hotspot estates on conversion and voucher-redemption metrics instead of gut feel. Revenue assurance has stopped being an audit-season event and become a nightly job.
Find Out Where Your Subscriber Revenue Is Leaking
A focused review of your AAA, billing, settlement, and provisioning chain — evidence first, tooling second.