Jim Gast's Home Page

Ph.D. University of Wisconsin - Madison, August, 2003.

Latest News

I retired and quickly discovered that I am not constitutionally capable of being retired. I woke up in the morning and did not know what to do with myself. So I took every CS class I could find at UW-Madison and earned a Ph.D under Drs. Paul Barford and Larry Landweber. It was more fun than the legal limit. And then I found out how expensive it can be to be retired.

I am currently doing Network Architecture at TDS Telecom in Madison. The commute is short and I get to return to my roots in telephony. I have some of the latest toys in IP Telephony and IP TV.

Basic Info

Wisconsin Advanced Internet Lab

CS 740 Students

CS 740 - Advanced Computer Networking.
The course covers 30 recent papers in Networking. Each paper is presented by a student with help from 2 other students. The papers and an overview are available on-line at http://www.cs.wisc.edu/~jgast/cs740/talks using E-Teach technology from http://eteach.cs.wisc.edu.

The course covers network implementation and protocol issues as the Internet is transformed from a file-delivery vehicle to a multimedia utility. Issues of multicasting, quality-of-service, e-commerce, privacy, wireless communications, and streaming audio and video were covered. There was also be discussion of migration to IP version 6.

Current Research

TCP connections in the Internet cooperate as good neighbors to mitigate congestion. UDP traffic has not been as responsive to implicit feedback from the network. Historically, the network provides this feedback by dropping packets, slowing down packets, or by Explicit Congestion Notification (ECN). Recent work in the IETF Differentiated Services working group has standardized class selector Per-Hop-Behaviors (PHBs). These could reduce the number of packet losses, improve fairness, and provide more useful feedback (back-pressure) to the ultimate sources and ultimate destinations. This work is largely separate from the work on multicast in the Protocol Independent Multicast (PIM) working group.

Lately, there has been increased interest in streaming video to smart phones, netbooks and laptops. Technologies have been offered to provide video "multi-screen" at several different resolutions and frame-rates. The result is often a bad neighbor to other applications that are sharing the bandwidth. And the streaming video, once locked into an unsustainable bandwidth, will look blocky and jumpy if competition for the bandwidth is bursty.

I want to improve layered multicast of streaming files (e.g. streaming video). Traditionally these applications probe to see if higher quality layers can be accommodated and count packet losses to assess the viability of each layer. Using a model like Paul Barford's WAN model, I want to investigate and quantitatively compare the existing unicast Per-Hop-Behaviors when used in a multicast environment. If these are unsatisfactory, I want to propose a PHB that would be more amenable to layered multicast.

Click here to see Jim's Curriculum Vitae.

Previous Semesters

Data Formats, Palindromes, and other Ghastly Stuff

This home page gives some basic information about SIDF, the System Independent Data Format, (ECMA-208 and ISO/IEC14863) to get you started, and interesting information about Palindromes (the word games) to keep you entertained. Or click on either of these ghastly links if you came looking for information on the Gast family genealogy or pictures of Pete and Sara's medieval wedding.

Contact Information:
Click here to send E-Mail to jgast@cs.wisc.edu.
-- or --
Click here to send a message to my home account, JGast@tds.net.
If it is an emergency (or a programming assignment is due soon), you can call me at home, 280-9599.

Tape and Optical Disk Formats

If you got to this page looking for information about the System Independent Data Format, including a copy of the specifications, press releases, information about joining the SIDF Association, and tools for analyzing SIDF tapes, follow this link to the SIDF Frequently Asked Questions page. SIDF is the data format that 14 vendors have agreed to use for interchange.

Status of SIDF

SIDF was accepted by ECMA, the European Computer Manufacturers Association, and designated ECMA-208. The vote closed in December, 1994 making SIDF the first major new file and label format approved by an international standards body in over a decade. Because fields are recorded in a tagged-field format, the SIDF tape standard is ideal for interchange between vendors, interchange between operating systems, and interchange between versions of operating systems as they change over time.

In October, 1995 SIDF passed the International Standards Organization (ISO) vote.

If you don't play with words . . . They'll Play with you:

Did you stay awake in 8th grade English class?

Do you remember what a Palindrome is?

Click here to see Jim's favorite words and phrases that are spelled the same forwards and backwards: Jim Gast's Palindrome Collection. There are some long poems and stories made up of palindromes that you are sure to enjoy.

If you are interested in the company named Palindrome: It was bought by Seagate in 1994 and became the start of Seagate Storage Management when Seagate Software was formed. There is even an alumni club at Colby Jordan's Home Page.

Version 3.1
GCS d+ s-:+ a++ C++@ UL+ P++ L++ E+(-) W++ N+ w+++ PS+ Y+ PGP++ t+ R+ e+++>$ h++ r+++

This page created and maintained by Jim Gast (jgast@cs.wisc.edu)