What is is the culprit here?
When I am sending Concatenated SMS using a TP-UDH header with my PDU message it takes exponentially the size and parts of the message to arrive compared to the same messages sent without UDH.
I suspect the carrier (LycaMobile) to badly handle concatenated SMS, but it could also be my modem (SIM7600E-H), or the PDU I am sending.
Here are 2*2 PDU I am using for testing, the first two are with UDH and signals Concatenated SMS, the other two yields the same text message but without UDH:
With UDH (10-30 minutes to arrive):
AT+CMGS=154
> 0061000b913376707070f000088d060804001d0201d83dde02002c0020d83dde03002c0020d83eddd8d83cdffb200d2642fe0f002c0020d83cdf0d002c0020d83cdf26fe0f002c0020d83cdf5e002c0020d83dde97002c0020d83ddcde002c0020d83cdf89002c00202764fe0f002c0020d83cdf46002c0020d83cdf510020002c0020d83dde02002c0020d83dde03002c0020d83eddd8d83cdffb
AT+CMGS=102
> 0061000b913376707070f0000859060804001d0202200d2642fe0f002c0020d83cdf0d002c0020d83cdf26fe0f002c0020d83cdf5e002c0020d83dde97002c0020d83ddcde002c0020d83cdf89002c00202764fe0f002c0020d83cdf46002c0020d83cdf510020
Without UDH (5-10 seconds to arrive):
AT+CMGS=147
> 0021000b913376707070f0000886d83dde02002c0020d83dde03002c0020d83eddd8d83cdffb200d2642fe0f002c0020d83cdf0d002c0020d83cdf26fe0f002c0020d83cdf5e002c0020d83dde97002c0020d83ddcde002c0020d83cdf89002c00202764fe0f002c0020d83cdf46002c0020d83cdf510020002c0020d83dde02002c0020d83dde03002c0020d83eddd8d83cdffb
AT+CMGS=95
> 0021000b913376707070f0000852200d2642fe0f002c0020d83cdf0d002c0020d83cdf26fe0f002c0020d83cdf5e002c0020d83dde97002c0020d83ddcde002c0020d83cdf89002c00202764fe0f002c0020d83cdf46002c0020d83cdf510020
Is this issue expected? Are they any ways to identify the culprit?
