Retry mechanism is enabled for every Kaleyra server for redundancy purpose. While sending SMS campaigns, if any campaign due to following reasons could not reach out to the customers, then Retry mechanism is initiated.
- Switch level errors
- Network congestion issues
- Operator congestion issues
- Subscriber Device Issues
Basically, SMSC is responsible for the relaying, storing and forwarding of a short message between an SME and operator. SMSC is notified of the message status through MAP operations.