How much airport time to leave between arrival from Sydney & air from Shanghai to Beijing?

I will arrive from Sydney at 18:25 at Shanghai Pu Dong Airport Terminal 2 and will need to catch a flight straight to Beijing. They appear to run fairly regularly from Terminal 2. I am not sure if I need to go through customs or whether I can go straight through to the waiting lounge for the domestic one. How much time do you think I should leave between them so that I don't miss the connecting air to Beijing?