Which WAN encapsulations can be configured on an asynchronous serial connection?
1.PPP
2.ATM
3.HDLC
4.SDLC
5.Frame Relay
Answer: A
Please do not freak out because ATM is an answer to this question. ATM is not covered in depth on the CCNA exam. PPP is mostly used for dial-up (async) services, but ATM could be used as well, though it typically is not used anymore since PPP is so efficient.