UK retail chains can’t afford lost sales due to internet outages. By adding 4G/5G SIM backup and automatic WAN failover, you keep POS terminals, card machines, click-and-collect systems and store apps online. This guide shows how to design policy-based routing or SD-WAN failover, cap SIM data, segment traffic with VLANs, and roll out central reporting across every store.
Key takeaways
- Instant failover to 4G/5G when FTTP/SOGEA/Leased Line drops — POS stays online.
- POS priority with VLANs & QoS; guest Wi-Fi is rate-limited during backup.
- SIM usage caps, alerts and policies prevent bill shock during extended outages.
- SD-WAN health checks and central dashboards for uptime and usage visibility.
Failover design: policy routing or SD-WAN
We prefer the primary circuit (FTTP/SOGEA/Leased Line) and fail to 4G/5G automatically using health-checks (pings, HTTP probes, SLA metrics). Policy-based routing ensures POS and payment traffic cut over first. With SD-WAN, you also get per-app priorities, jitter and loss monitoring, and templated rollouts to every branch.
Protecting POS & payments during backup
- POS VLAN with QoS so card authorisations remain fast and reliable.
- Guest Wi-Fi gets bandwidth caps and client isolation to conserve SIM data.
- Heavy services (updates/streaming) pause until the primary link returns.
Data controls: caps, alerts & acceptable use
We apply data thresholds and alerts (email/SMS) per site. If usage spikes, policies throttle guest VLANs or temporarily block non-essential services. Managers see real-time SIM usage by store and region.
Central reporting & store health
Dashboards show uptime, failover events, latency, and data consumption. Monthly reports identify sites that regularly hit backup and may need FTTP upgrades or a Leased Line.
Related guides
Recently asked questions
How fast is 4G/5G backup for card payments?
More than sufficient — POS traffic is tiny. With QoS and a dedicated POS VLAN, card authorisations remain snappy.
Can we stop staff or guests using lots of data during failover?
Yes — we apply VLAN rate limits, client isolation and policy blocks for non-essential apps while on backup, then automatically restore after recovery.
Will failover happen automatically without staff intervention?
Yes. Health-checks drive automatic cutover and reversion. Stores get alerts so managers know when they are on backup.
Does this work with FTTP, SOGEA and Leased Lines?
Yes. The design is access-agnostic. Sites with frequent failovers may justify an upgrade to a Leased Line for better SLAs.