CSCI E-131b Communication Protocols and Internet Architectures [Lecture 1]

Lecture Observations

  • To understand the internet architecture, you must understand the foundation.
  • The course is not a course on specific products (Cisco, etc).
  • It's also not a programming course.
  • We'll need to understand the error characteristics of wired vs wireless, and why to choose one over the other.
  • Network diagrams are always out of date, things change and boxes move.
  • How do telephone networks work? I don't quite know but a few students did know know the transmission rates.
  • Transmission rate is based on distance.
  • Bit errors are rare, 1 error for every million bits. As distance increases so does the probably of a bit error occurring.
  • It's typically that a particular server/room to only have one error in an entire 7 day span.
  • If an error occurs in a packet the whole packet is thrown away.
  • It was less expensive to layout a HUGE wire that could support 24 channels rather than to use a single wire with the latest packet switching technology.
  • Multiplexing is like asking the whole class to exit the front door. We would have to form a single-file to squeeze out of the room.
  • Circuit-switching involved physically connecting wires to form a connection from Boston > Providence > Hartford > New York
  • Fixed Time Division Multiplexing is easy to develop but inefficient. Especially when certain connections are not being used. It's more or less specifying a permanent time-slot for each connection.
  • The following are important components of a network: error correction, error detection, user interface, applications (voip, email, web), fragmentation, encryption, flow control, the physical interface, sequencing, addressing
  • A packet is encapsulated. It has a header and a payload, where a payload may also have it's own header and payload.

Observations about Len Evenchik and the classroom

  • The classrooms in the Maxwell Dworkin are very high-tech and CLEAN.
  • This class is going to be online-only next semester and I am so glad I am able to experience this in person.
  • Professor Evenchik is very clear and I think he likes getting the class involved.
  • The TAs were introduce and I hope to meet them during the class meetings.
  • Occasionally he will sneak in a joke and some humor into the lecture.
  • There was one 3-5 minute break during the two-hour class.
  • The students in the class range from young to mature and was very diverse.

A few thoughts...
I was a little intimidated during class to ask a question. I need to get over my fear of sounding "stupid". At the end of the class I wanted to introduce myself to Len and I also chickened out. I felt like just saying "Hi" would be a waste of his time.

Next class, I will try to prepare a question from the reading... Actually, I am having trouble understanding some of the exercises at the end of the chapter. I wish there were more examples.

  1. gravatar

    # by Anonymous - September 11, 2011 at 7:31 PM

    Can you answer this ?
    Imagine that a bicycle messenger is given six (6) USB memory sticks, each of which contains 8 gigabytes of data. Given that the courier can travel at 30 km per hour through traffic, for what range of distance does the courier have a higher data rate than a transmission line whose data rate (excluding overhead) is 150 Mbps