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Signal & Syntax · Messaging and A2P

What Is an SMSC?

An SMSC (Short Message Service Center) stores and forwards SMS. The SMSC queries the HLR, then delivers each message to the serving network.

Also calledShort Message Service Center · SMS center

SMSC in Practice

Every mobile operator runs an SMSC. The SMSC sends SRI-SM to the HLR to locate the recipient. If the handset is unreachable, the SMSC holds the message and retries. Aggregators and gateways submit A2P traffic to SMSCs over SMPP.

Where ScoreMachine Fits

score.phone.validation.mnp + score.phone.ehlr
carrieraccessibility

Before submission to the SMSC: carrier from MNP and accessibility from eHLR.

Related Terms

SMPP SMPP (Short Message Peer-to-Peer) is the open protocol linking an SMSC to external systems over TCP/IP. SRI-SM SRI-SM (Send Routing Info for Short Message) is the MAP query an SMSC sends the HLR. Delivery receipt A delivery receipt (DLR) is the status report an operator returns for each SMS. SMS gateway An SMS gateway connects software to mobile networks for sending and receiving SMS.

Read the Guide

Guide

How A2P SMS Reaches a Handset

The path from an API call to a delivery receipt. Read the guide →

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