Arecont Vision Embedded Systems Engineer interview questions

Phone interview with online white board. Asked to recreate the TCP state diagram, recall the single 8086 ask instruction to atomically test and set/clear a bit, a derivation of a summation of a series and print out a binary tree. This firm has had some tough experiences in hiring in the past and are pretty stringent about the interviewing process (and rightly so), but the interview did seem to be over-the-top and in my opinion.