Comment by proberts

That depends on a number of factors, such as your activities/purpose when you are in the U.S. (whether these activities constitute "employment" and if so whether they are in line with your H-1B position and job duties), your compensation when you are in the U.S. (are you getting paid and if so, how much and by whom), etc. The question here really is whether H-1B work authorization is required or whether ESTA business travel is fine.