Reference section - SMPP


SMPP enquire_link

SMPP (Short Message Peer-to-Peer) is an open, industry standard protocol designed to provide a flexible data communications interface for the transfer of short message data between External Short Message Entities (ESME), Routing Entities (RE) and Message Centres (MC). The SMPP protocol is a means by which applications can send SMS messages to mobile devices and receive SMS from mobile devices.

4.1.2 Enquire Link Operation

This PDU can be originated by either the ESME or MC and is used to provide a confidence check of the communication path between an ESME and a MC. On receipt of this request the receiving party should respond with an enquire_link_resp, thus verifying that the application level connection between the MC and the ESME is functioning. The ESME may also respond by sending any valid SMPP primitive.

The enquire_link can be sent when the session is in the open, bound (TX, RX or TRX), unbound or outbound states. Typical values for the period of inactivity before the ESME or MC originate this operation are between 30s and 120s. enquire_link Syntax

Field NameSize OctetsTypeDescriptionRef.
command_length4IntegerDefines the overall length of the PDU.4.7.4
sequence_number4IntegerSet to a unique sequence number. The associated enquire_link_resp PDU should echo the same sequence number.4.7.24 enquire_link_resp Syntax

The enquire_link_resp PDU is used to reply to an enquire_link request.

Field NameSize OctetsTypeDescriptionRef.
command_length4IntegerDefines the overall length of the PDU.4.7.4
sequence_number4IntegerSet to the same sequence number of original enquire_link PDU.4.7.24

SMPP Tools and Services

Services from Melrose Labs (e.g. Tyr SMS Gateway and SMPP SMS Gateway ) support SMPP v5 and the earlier versions, v3.3 and v3.4.

SMSC Simulator

Looking to test your SMS application or SMS-enabled application before connecting to a live SMS gateway or SMSC? SMSC Simulator enables you to test using SMPP v3.3, v3.4 and v5.
Read more about SMSC Simulator >

SMPP Clients

Send and receive SMS using an SMPP account and browser-based SMPP client.

* SMPP session between web browser and provider.

SMS Code Bench

SMS messaging code sample and development playground. Collection of editable and runnable code samples in a variety of languages for different SMS interactions.
SMS Code Bench >

Send SMS programmatically with SMPP

Send SMS programmatically with SMPP using Python, Java, Go, Perl, C++, C#, Node.js, Ruby and PHP.

SMPP Load Test

Perform an SMS load test using SMPP from your web browser and view the results in realtime. SMPP Load Test tool submits SMS messages using SMPP at the specified rate. Messages are sent to one or more mobile numbers in a range from a single source address or range of source addresses.
Use the online SMPP Load Test tool >

SMPP Analyser

The SMPP Analyser acts as an SMPP proxy, with the client application binding to the service and the service onward binding to the SMSC or SMS Gateway. Packet captures can be viewed in your browser or exported into Wireshark.
Use the online SMPP Analyser >

Message Hub

Message routing between applications (uses SMPP protocol). For use in IoT, chat applications, asyncronous notification in web applications, and other applications.
Message Hub documentation >


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