MS behavior with dysfunctional GPRS

Hi.

Imagine following configuration: - GSM network advertises GPRS capabilities in System Information messages - It's not actually available (SGSN crashed, all the timeslots are occupied by TCH etc)

What would be expected behavior for MS in this scenario?

Shall it switch to alternative network in hope of getting promised GPRS? Shall it hang on the currently camped network providing voice/sms only? Which spec(s) cover that? What could be decision factors for the MS? SIM entries, some data in SI, some timeout somewhere, smth else?