Advanced Internet Services - CS 6998-03: Homework 5

1. RSVP (5 pts): Compute the resource consumption for the different RSVP resource reservation styles (wildcard filter, fixed filter, shared explicit) in the case of a audio conference with at most two sources active concurrently. Assume that the network has the shape of a m-ary tree, with n end nodes as leaves. The remaining tree nodes are routers. Resource consumption is computed as the number of links times the number of bandwidth units reserved, with each active audio source requiring one bandwidth unit. For further information on these styles, see RFC .
2. Resource reservation (5 pts.): What are the advantages and disadvantages of sender- and receiver-based resource reservation?
3. ATM rate control (5 pts): Consider a video source that has an average rate of 1 Mb/s (1 Mb = 1,000,000 bit). It transmits data as 48-byte cells (so-called asynchronous transfer mode or ATM). Video is sent with a rate of 30 frames a second. Within each video frame, the cells are spaced 0.3 ms apart. (There is then a slightly larger gap between the end of the last frame and the first cell of the next frame.) We use the Generic Cell Rate Algorithm (GCRA) to police the mean rate of the source. If the parameter T is set to correspond to the average cell rate, what does the parameter L need to be set to to avoid dropping cells?
4. Delay bounds (5 pts.): Compute the delay bound according to the WFQ formula for two ways of providing Internet telephony service with 1000 phone calls, with 16 kb/s each. on a network with 10 hops connected by links with a bandwidth of 45 Mb/s (T3). The maximum packet length for non-voice packets is 1500 bytes.
   • All calls are carried as invidual reservations.
   • All phone calls are grouped into a single scheduling class.

   The maximum packet length in the network is 1500 bytes. Voice calls use RTP over UDP and generate packets every 50 ms. Based on this information, estimate a reasonable bucket size for voice traffic. Hint: Note that the packets generated by different phone calls are not guaranteed to be evenly spread out over the 50 ms interval.

5. CGI programming: Write a cgi-bin script in C or Java that accepts form input and then creates an HTML page with the input values as well as the name or IP address of the host where the request originated from. The form should accept a name, a 5-digit zip code, a choice of SEAS departments, an email address and a list of programming languages understood (chosen from C, Java, Tcl, Cobol, Fortran, Pascal). The form should be presented as a table. A JavaScript script should check whether the USPS zip code is in New York City (NYC zip codes are of the form 100xx, 101xx and 102xx).

   The HTML page generated as a reply to the submission should display all the entered information (note: some fields might not be filled by the user). Also, send back a message via email (to the email address provided by the user, if any), that contains: 1- the HTML input page, 2- the cgi-script in C, 3- the java script, 4- the reply form (if not all automatically generated by the cgi-script) and 5- the data submitted by the user. The email should be sent by your cgi-script (you may need to use the unix command system(3S) or popen(3S)).

   Provide the URL where the page can be tested.

   (The necessary material will be covered in the Apr. 14 lecture.)