Topics
Filter topics and expand the sections you want.
General overview What SMS is and why business users should set expectations
SMS (Short Message Service) delivers short messages to and from mobile devices. Networks ultimately control delivery behavior,
so vendors should avoid unrealistic promises. Understanding network processing helps align expectations.
Definitions Network, modem, SMSC, statuses, validity
In this KB, SMS is considered “from GSM modem to cellphone” for business use. Key terms include SMSC (Short Message Service Centre),
statuses (Pending/Delivered/Failed), and validity period (up to 3 days).
Validity & network timeout Why some messages never “fail”
Networks queue messages when phones are unavailable. If validity expires, a failure status may be generated upon retry triggers.
Network timeout behaviors vary, but planning around validity helps operational reliability.
Message size & splitting 160 characters and multi-part SMS
SMS is limited to 160 characters. Longer messages may be split into multiple parts, and handsets show part counts (e.g., 1/3, 2/3, 3/3).
Status messages Pending, Delivered, Failed
Networks typically return statuses like Pending, Delivered, and Failed. Status handling is critical for operational reporting and retries.
SMS sending process End-to-end flow from modem to network to handset
A typical flow: modem sends → SMSC queues/retries → handset receives → network returns status → recipient may reply (new SMS).
For the original legacy diagram, see below.
Want the full legacy paper? The original KB content is preserved in this build, but redesigned for readability.
If you want every paragraph converted into modern sections, tell me and I’ll split it into a multi-page KB.
Need help with SMS behavior or delivery?
Request an online demo and Q&A. We’ll show how SMS Suite handles statuses, retries, validity and inbound workflows.