SMSC
A short message service center stores and forwards each submitted SMS to the destination network and, on request, returns a final status report.
Definitions only — a term explained here is not a service we sell.
A short message service center receives a submitted SMS, stores it and forwards it toward the destination network. It retries until the validity period expires and, if a receipt was requested, returns a status report on the final outcome; some centers also send intermediate notifications.
Store and forward
The center stores the message, asks the home location register where the recipient is and forwards it to the serving network. If the handset is offline, it queues and retries until the validity period expires.
Where the receipt comes from
- Application
- SMPP gateway
- SMSC
- HLR / HSS
- MSC / MME
- Handset
- Delivery receipt
Text description
The application submits through an SMPP gateway; the SMSC asks the HLR/HSS where the subscriber is, then routes through the MSC/MME to the handset. A delivery receipt ends the path.
What the receipt proves
The center generates the status report, not the handset. Depending on the receipt type and the network, it can mean the message reached the center, the handset or neither. Codes differ between centers, so normalize them before reporting.
Queuing and retries decide whether it arrives minutes later or is discarded. Duplicates appear when a lost receipt makes the sender retry; use the message ID and make handling idempotent. For concatenated messages, confirm that all parts go through the same center and that the reassembly timer is long enough. SMS route testing covers what to measure.