We have developed an SMPP server based on CloudHopper SMPP library. The system is in production processing a considerable volume of messages everyday.
Customers are allowed to maintain multiple TX binds for a higher throughput and redundancy. Recently we identified that a few of our customers send segmented messages (message parts) over multiple binds. So we receive parts of a single SMS over different binds from the same customer (same SystemId) and those are valid (in UDH, Having the same reference number, valid seq no etc). We support concatenation on a bind level, but not across multiple binds.
Is it a standard/good practise to support concatenation for parts sent over multiple binds? Message reference number in the UDH header for concatenated messages should be unique for all binds created by an SMPP gateway? Any thoughts on this are welcome
UPDATE: Regarding MessageRef no in UDH, we understood that there is no guarantee that it will be unique across multiple binds. (We see repeated MessageRef in concurrent binds from the same customer). Now we concatenate parts if they have the same MessageRef no and also the same destination number. We believe it is rare to receive two part sequences at the same time with equal MessageRef numbers, going towards the same mobile.
As long as a concatenated messages have valid UDH, I see not issue on this. SMSC further is usually transparent on this, altough it knows the multipart messages belong to single SMS message. From a practice side, customers usually have limitation on bind side just for 1 transmitter (on gigabit network should not be an issue), but this depends on number of messages/s they want to submit. I usually have my own queue in between, so the submit response does not affect SMSC submit delay.