Overview

It is possible that for your SMSC you find in your trace files that for concatenated messages, some message fragments have TP-MMS (More Messages to Send) value as 0, while others have the TP-MMS value as 1. For instance: 

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You wish to know why different fragments have differing TP-MMS values​.

Information

• Please note that this behavior is expected and not anomalous. The TP-MMS parameter is used not only for concatenated messages but also for when there are more messages stored in the Service center (SC) for the same recipient.
• According to 3gpp specifications - More-Messages-To-Send (MMS): The More-Messages-to-Send is the information element by which the SC informs the MS that there is one or more messages waiting in that SC to be delivered to the MS. The More-Messages-to-Send information element makes use of a Boolean parameter, TP-More-Messages-to-Send (TP-MMS)
• Thus, the TP-MMS value of fragments being 0 or 1 could depend on how the messages are getting stored and delivered.
  • For MO/AO messages that go via the AMS, the RTR will set the MMS flag to 0 (meaning there are more messages to be sent) if the message is NOT the last message to that recipient. This means there are indeed more message from the same RTR to be sent to that recipient number.
  • For MT messages, RTR decodes the incoming message and if it finds that the MMS field is set to 0 then the RTR forwards the same information to the outgoing leg with the TCAP layer behavior as described in MAP phase 2 and 3 specifications.