It does sound like night terrors.
Waking a child up only prolongs the episode and upsets them more, and they might remember it (children don't usually remember night terrors). I know it's hard, but the best thing really is to do nothing other than remain near and available in case he does wake up and needs you.
If he does wake up, don't try to talk to him, do not ask him what is wrong, just be calm, hold him and do whatever things normally comfort him, e.g., nursing, rocking, singing.
Some things that can make the attacks more likely: trauma, stress, change of any kind, overstimulation (TV/video games) before bed, being very tired before going to bed (i.e. staying up too late.)
I had night terrors into adulthood, if you have any other questions feel free to PM me.