Key takeaways
- Failover sends a message through an alternative route when the first one fails or performs badly.
- It is different from channel fallback, which moves a message from one channel (for example RCS) to another (SMS).
- Good failover needs fast detection and a rule that prevents duplicate messages.
- Ask how failure is detected, how quickly the switch happens and whether you can see which route was used.
Why routes fail
Most of these last minutes or hours and affect one country or one operator, not the whole network. That is why a single route is a risk, and why a provider with several routes per destination matters.
- Congestion at a peak, for example when many codes are sent at once
- Planned or unplanned maintenance at an operator or an intermediary
- A change in filtering that suddenly blocks certain content or senders
- A fault between the provider and the operator
How failover works
The provider watches signals such as error responses, timeouts and the share of failed delivery reports per route. When a route crosses a threshold, new messages are sent through an alternative route, and messages that failed early can be retried through it.
The details matter: how long the provider waits, how many failures it needs to see, and whether it switches back automatically when the route recovers.
Route failover or channel fallback?
Route failover keeps the same channel (SMS) and changes the path. Channel fallback changes the channel: if an RCS message cannot be delivered as RCS, it is sent as SMS instead. Many programmes use both.
They solve different problems, so ask a provider about each one separately.
The duplicate problem
If a message is retried while the first attempt is still in flight, the person can receive it twice. For a one-time code that is annoying; for a payment notice it can be worse.
The safest rule is to retry only on a clear failure signal, and to give each message an identifier so that your own system and the provider can recognise a repeat.
Questions to ask a provider
- How is a failing route detected, and how fast is traffic moved?
- How many routes exist per destination, and are they direct or through partners?
- Can I see which route carried each message?
- Do you get notified when routing changes for a country you use?
- How does the provider keep its own platform available if one of its systems fails?
How ZafeConnect fits
ZafeConnect offers intelligent routing and fallback, failover systems, multiple upstream providers and direct operator connections, complemented by partner direct routes, across 190+ countries. A reported delivery rate is not a delivery guarantee: routes still depend on operators and recipients’ devices.