OTP and Authentication Messaging
One-time passcodes have to arrive within seconds or the user gives up. We carry OTP and verification SMS on approved routes monitored for speed as well as delivery.
What is OTP SMS?
OTP (one-time password) SMS is a text message carrying a short code that a user enters to prove they control a phone number, typically at sign-up, login or payment. It is the most common form of A2P authentication traffic. Because the user is waiting, OTP depends on delivery speed as well as delivery rate, and it is a frequent target of SMS pumping fraud.
Why OTP needs dedicated routes
Most A2P traffic tolerates a short delay. OTP does not: a code that arrives after the user has abandoned the screen is a failed sign-up or payment. Grey routes make this worse, because operator firewalls block or delay them unpredictably. OTP traffic should travel on direct and approved routes that are watched for speed.
Latency and delivery monitoring
- Delivery rate and time to delivery, measured per destination network and route.
- Delivery reports from the delivering network, not generated early to look successful.
- Traffic moved to alternative approved routes when speed or delivery drops.
Protection against SMS pumping
Artificially inflated traffic costs the sender money for messages nobody wanted. We recommend, and can help design, controls on your side: limits per destination number range and country, CAPTCHA or device checks before a code is sent, and monitoring of the ratio between codes sent and codes verified. On our side, unusual surges toward specific number ranges are flagged.
FlashCall as a fallback
A flash call verifies a number with a missed call whose caller ID carries the code; the app reads it automatically on Android. It can be cheaper than SMS and works where SMS delivery is weak, but it is not supported the same way on every device. Many verification flows try one method and fall back to the other. See FlashCall authentication.
Connecting
OTP traffic uses the same SMPP or HTTP connection as other A2P traffic, flagged as authentication so it is routed accordingly. See SMPP connectivity.
Frequently asked questions
What is SMS pumping?
SMS pumping, also called artificially inflated traffic (AIT), is fraud in which attackers trigger large numbers of OTP requests to number ranges that share revenue with them. The sender pays for messages no real user asked for. Rate limits per number range and country, and watching the ratio of codes sent to codes entered, are the main defences.
How fast is OTP delivery?
It depends on the destination network and route. We monitor latency per destination and route, and steer OTP traffic to routes that deliver quickly, not just reliably. We do not publish a single guaranteed time because it varies by country and operator.
Should I add FlashCall as a fallback?
For some markets and devices it improves completion and cost. Compare the two methods in FlashCall vs SMS OTP.
Related
Test OTP delivery with us
Tell us your top destination countries, monthly verification volume and current delivery problems. We will set up test traffic.
- Email: sales@wisenetwork.co
- Phone: +961 3 085 999