SMSC Simulator

SMPP SMSC simulator to test SMS messaging applications.


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SMSC simulator for testing your SMS applications and messaging infrastructure using the SMPP protocol.

Categories: Conversational Messaging Messaging Bulk SMS 

Melrose Labs operates SMSC simulators (aka SMPP server simulators) for use in the development and testing of SMS text messaging capabilities within applications. They simulate SMSCs (short message service centres) and SMPP SMS gateways, with support for SMPP v3.3, SMPP v3.4 and SMPP v5. Our SMSC simulators are also part of Melrose Labs SMPP Implementation Testing.


The simulators can be used to test the MT SMS (to mobiles) and MO SMS (from mobiles) operation of an application. Applications send SMS messages to mobiles by submitting messages to the SMSC Simulator service using SMPP. The SMSC simulators simulate the delivery of the messages, including the generation of delivery receipts back to the application. SMS messages from mobile numbers can also be submitted and delivered to the SMS application (see Simulate Inbound SMS to your Application).


The advantage of the SMSC simulators is that you can send SMS messages from your application without messages being delivered to real mobile phones and therefore without any SMS delivery costs. Stress testing of your application can also be performed to show how your application behaves under load and various other scenarios tested before live operation and without affecting production SMSCs. The SMSC simulators can handle high rates of SMS and a high number of simultaneous connections from your application.


Using the SMSC Simulator service

The SMSC Simulator service is publicly available and connection details dedicated to individual users are provided (see below for your SMPP account details). SMPP over TLS support is available for SMS applications to connect securely (SMPP TLS port: 8775).


SMSC Simulator SMPP Account Details

The system ID and password are dynamically updated on this webpage. The details below are allocated for your sole use:

  • Server: smscsim.melroselabs.com
  • Port: 2775 (non-TLS), 8775 (TLS)
  • System ID: 5530036
  • Password: CSWFDR
  • System type: null

Use the above SMPP parameters to bind to the SMSC simulators. If you need any help then send us a support request and we will quickly get back to you.

Simulate Inbound SMS to your Application

To simulate MO SMS (i.e. inbound SMS or person-to-application SMS) from a mobile to your application, you submit a message using the above SMPP account details to a destination_address that contains the above system ID. This enables you to use an SMPP client to compose messages or set of messages, and submit them from a single or multiple mobile numbers. Ensure that you prepend or append at least one digit to your system ID to have a destination address that is at least 8 digits in length, otherwise the simulator will reject the submission due to a too short destination address. We also support the use of schedule_delivery_time in the submit_sm to schedule delivery of inbound messages.


Example: If your system ID was "1234567" then to send an inbound SMS to your application you would use a separate SMPP transmitter (TX) bind to submit a message (submit_sm) to the destination_address "441234567" (digits in bold are your system ID). This would cause the SMSC Simulator service to send a deliver_sm to your application with the source_addr and destination_addr that you set in the submit_sm.

SMPP operations supported by the simulators

SMSC simulators last updated 17 Nov 2019


We are working to ensure that our simulators allow you to test most, if not all, aspects of SMPP applications such as applications with SMS support and SMS infrastructure. Operations currently supported by the simulators are shown below. Further operations will be provided in future and frequent updates.


  • Session Management:
    • bind_receiver/resp - Used for receiving delivery receipts.
    • bind_transmitter/resp - Used for submitting messages.
    • bind_transceiver/resp - Supported for v3.4 and v5, and used for submitting messages and receiving delivery receipts.
    • unbind/resp - ESME unbinding from SMSC and SMSC issues unbind_resp. SMSC unbinding from ESME when ESME unresponsive.
    • enquire_link/resp - Will respond to enquire_link from ESME and will issue enquire_link to ESME every 120s of inactivity.
  • Message Submission:
    • submit_sm/resp - Will issue positive response with message_id of 8 characters in length for v3.3 and 64 characters for v3.4 and v5. Will issue error response (ESME_INVDSTADR/0x0000000B) if destination_address less than 8 characters in length.
  • Message Delivery:
    • deliver_sm/resp - Delivery receipts sent to ESME on receiver binds (SMPP v3.3, 3.4 and v5) and transceiver binds (SMPP v3.4 and v5 only). deliver_sm short_message field with textual receipt plus TLVs containing message ID (i.e. receipted_message_id), status of message (i.e. message_state with value of 2 for DELIVERED) and error (i.e. network_error_code with value of zero indicating no error)

Melrose Labs SMSC Simulator Abbreviated SMPP PICS

SMSC Simulator Abbreviated SMPP Protocol Implementation Conformance Statement

Operations Supported

ItemFunctional Unit/DescriptionSupported
PDU-OUTBINDIs the outbind PDU supported?NO
PDU-BIND-TRANSMITTERIs the bind transmitter PDU supported?YES
PDU-BIND-RECEIVERIs the bind receiver PDU supported?YES
PDU-BIND-TRANSCEIVERIs the bind transceiver PDU supported?YES
PDU-UNBINDIs the unbind PDU supported?YES
PDU-ESME-GENERIC-NACKIs the generic_nack PDU initiated by the EMSE supported?YES
PDU-SMSC-GENERIC-NACKIs the generic_nack PDU initiated by the SMSC supported?YES
PDU-SUBMIT-SMIs the submit_sm PDU supported?

  • schedule_delivery_time - absolute and relative supported
  • validity_period - ignored
  • registered_delivery - SMSC delivery receipt supported
YES
PDU-SUBMIT-MULTIIs the submit_multi PDU supported?NO
PDU-DELIVER-SMIs the deliver_sm PDU supported?YES
PDU-ESME-DATAIs the data_sm PDU initiated by the EMSE supported?NO
PDU-SMSC-DATAIs the data_sm PDU initiated by the SMSC supported?NO
PDU-QUERYIs the query_sm PDU supported?NO
PDU-CANCELIs the cancel_sm PDU supported?NO
PDU-REPLACEIs the replace_sm PDU supported?NO
PDU-ESME-ENQUIRE-LINKIs the enquire_link PDU initiated by the EMSE supported?YES
PDU-SMSC-ENQUIRE-LINKIs the enquire_link PDU initiated by the SMSC supported?YES
PDU-ALERTIs the alert_notification PDU supported?NO


Notes on using the SMSC Simulator service

  1. SMPP (Short Message Peer-to-Peer) protocol must be used to connect to the simulator.
  2. Use SMPP v3.3, v3.4 or v5 and specify the version in the bind request.
  3. Bind using one or more transmitter (TX), receiver (RX) or transceiver (TRX) binds.
  4. Use transceiver (TRX) or receiver (RX) binds to receive delivery receipts.
  5. If a delivery receipt has been requested for a message, a receipt will be returned to your application in 3-12 seconds (random) after the submit_sm_resp. If there is no existing TRX or RX bind, then the receipt will be discarded.
  6. Mobile numbers (MSISDNs) should be in international format.
  7. TLS 1.1 and up are supported for SMPP sessions. SSL and TLS 1.0 are not supported for connections.

If you wish to perform testing using production SMSCs for delivery to mobiles, then we recommend that you use the HSL Mobile SMSCarrier service. If you wish your application to receive messages from mobiles then see HSL Mobile's Advanced Services.


Source code for our SMSC simulator can be found in the Melrose Labs GitHub repository at smpp-smsc-simulator.


For production SMSCs and SMS gateways we suggest you take a look at the following:


Service snapshot

  • Test SMS applications and messaging infrastructure without SMS cost
  • SMPP v3.3, v3.4 and v5
  • MT and MO SMS testing (A2P and P2A)
  • SMPP over TCP and SMPP over TLS 1.1+ supported
  • SMPP test tool

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