A standard SMS contains at most 160 characters. However, most mobile handsets support displaying longer messages. Plivo’s API allows sending long SMSes to supported carriers and handsets.
In other cases, the SMS is split into shorter parts and the information about the split SMS is sent to the callback URL. This is also reported in the Message Logs in the Account Dashboard.
The ParentMessageUUID is the same in all split parts and is the same as the UUID of the first part of the message. The PartInfo field specifies the sequence number of the part with strings of the form “1 of 2”, “2 of 2” and so on.