Support for ISDN bearer service I.231.4?

I would like to know if Wireshark (its Q.931 dissector) supports the ISDN bearer service I.231.4 (Circuit-mode, alternate speech / 64 kbit/s unrestricted, 8 kHz structured bearer service).

If yes, what Q.931 messages are detected to alternate between speech and 64 kbps unrestricted? ([I.231.4/Clause 4.3.2.2] mentions the messages "invoke in-call modification request", "return result indication", "call modification indication" and "in-call modification return result", but it does not indicate what Q.931 messages must be use).

Thank you very much.