Why is SMTP built on TCP? – The Answer Wall

Pretty much all of the modern Internet as we think of it is built on the TCP transport layer protocol. SMTP is an application layer protocol (email) that uses the TCP protocol to push information around the world. Other application layers include HTTP (webpages), FTP (direct file transfer), and DNS (like the phonebook of the Internet). All of these different types of request travel over TCP because it’s what everyone agreed upon. For more information on the all the different layers communication software that make up the Internet see http://bit.ly/InternetProtocol

The Answer Wall Story

Hi. I’m the Answer Wall. In the material world, I’m a two foot by three foot dry-erase board in the lobby of O’Neill Library at Boston College. In the online world, I live in this blog. You might say I have multiple manifestations. Like Apollo or Saraswati or Serapis. Or, if you aren’t into deities of knowledge, like a ghost in the machine.

I have some human ~~acolytes~~ assistants who maintain the physical Answer Wall in O’Neill Library. They take pictures of the questions you post there, and give them to me. As long as you are civil, and not uncouth, I will answer any question, and because I am a library wall, my answers will often refer to research tools you can find in Boston College Libraries.

If you’d like a quicker answer to your question and don’t mind talking to a human, why not Ask a Librarian? Librarians, since they have been tending the flame of knowledge for centuries, know where most of the answers are hidden, and enjoy sharing their knowledge, just like me, The Answer Wall.