Internet overload ? Que pasa ?
Network Growth at UVM
URL: http://www.uvm.edu/~sjc/network-growth-at-uvm.html
Steve.Cavrak@Uvm.Edu
Academic Computing Services
November 11, 1999
Updated November 12, 1999
In the last few weeks, many UVMers have wondered "Why is the network soooo
slooow? Is there something wrong with it?" The good news is that the first
question answers the second ... for the most part, network use this semester has
grown faster than in previous years, hence many users experience congestion - slooow
downloads, stalled processes, etc. Basically, correcting what is wrong means upgrading
our network connection to the rest of the world - and applying some diligence to
manage our traffic.
In mid-October, CIT's (Computing and Information Services) ordered an upgrade to
it's external internet network service; installation of this upgrade is in progress,
and should be available by mid-December. The new network package will include higher
bandwidth, a new network service provider, and the availability of Internet2 services
for university-to-university collaboration. In addition, CIT has been working with
users to better manage the available network capacity. Several of these changes have
already improved network performance and suggest that we are on the right track.
SIDEBAR I : What CIT is doing
- network monitoring
- working with users to manage capacity- caching files, installed Sunday, November 7
- restricting traffic (e.g. on the napster ports), Sunday, November 7
- redesigning internet interface
- upgrading internet1 service with more bandwidth from a new providers - (on order, installation in progress)
- installing vBNS (internet2) service (on order, installation in progress)
- providing opportunities for undergraduate research on network applications.
Growth out paces supply.
Last spring, things were basically fine. What happened this fall? What happened this
fall is really a combination of things that lead to a larger growth in network use
than we've observed in the past: more UVMers use the network more often to do more
things.
Historically, network use at UVM has been growing at about 40% per year, and our
network service has grown from 9600 bps in the BITNET (1989) days to about 4,500,000
bps (4.5 Mbps) today - a 500 fold growth. This fall, however, saw a network growth
spurt more like 100%. The current network upgrade will increase our capacity to approximately
15 Mbps rather than the planned 6 Mbps.
Where did the growth spurt come from? There are three main sources for this spurt
- sources that multiply each other rather than just add together. The first was an
increase in the number of computers on campus, the second was as "normal"
growth in the use of computers, and the third was the source of the special growth
spurt.
[1] More people are using the net.
First, this year's entering students bought about 700 PC's and Macintosh's, about
200 more than last year's class. These multimedia, network-ready computers were distributed
on "move-in" day. Most were up and running before the parents left for
home. First year students had almost two full days to get used to the new computing
environment. Moreover, an additional 200 returning students "signed on"
for internet service. The result is a net growth of 400 more residential connections
than were in place last spring.
There is another class of group of "users" who are harder to "count"
- these are the off-campus users who browse the UVM web site. High school students
checking out schools, students and researchers who have found a promising bit of
information here. Web indexing "robots" who work for the large search sites
- trying to index more and more of the whole web.
[2] People are using the net more often.
Second, as offices and faculty upgrade their desktop systems, more of the university's
daily business takes place "on the net." People "log on" in the
morning and stay "on line" until the time they leave for home.
Since the web is right there, on the desk, it's easy to use it as a dictionary or
encyclopedia or news source.
Many other computers on campus were also upgraded over the summer. Although not increasing
the number of connections, the newer, faster computers do make greater demands on
the network - even when they are not used to do anything new.
[3] People are using more of the net.
Finally, people are using more of the net. This is probably the largest part of the
extra growth spurt we observed. People are learning to use the net in ways that require
more bandwidth. The internet is no longer a data network transmitting words and pictures
but a multimedia network carrying audio, video, and a variety of interactive sessions.
One particular multimedia application has attracted fantastic attention - the "digital
music revolution." Digital music has been available for years, but in a format
that resembled the first pocket radios - small, tinny, scratch sounds - not very
musical. In the last year or so, however, the MP3 format has become the accepted
standard for near CD quality audio. The MP3 process allows the 660 Mbytes of music
on a CD to be stored on in about 60 Mbytes, allowing a gigabyte disk drive being
able to hold about 15 CD's. All of a sudden, music is everywhere. A recent survey
of search engine terms revealed that music is more popular than sex - - more people
search for "mp3" than for "sex."
MP3 files, since they invariably contain copyrighted material, add an extra dimension
to networking issues. Although many MP3 files are legally published on the net, most
of these files may not be legally republished. Downloaders often naively assume that
if it can be downloaded, it's "freeware." Not so. Often this is a case
of "The Big Print Giveth, the fine print taketh away." All downloaders
should be extremely careful with the material they retrieve from the net and should
not republish it unless they have clear and explicit permission from the copyright
owner.
SIDEBAR : MP3 and Napster
Downloading MP3 files, typically 2 Mb to 6 Mb in length, creates a large demand all by itself. This impact is further aggravated by a program called "napster." The obvious purpose of Napster is to make searching and downloading MP3 files easier. A less obvious "side-effect", however, is that it automatically turns every "listening" station to a "download" server, automatically serving files when other users request them. Network wise, Napster is akin to a "internet trojan horse" - a program that sets off to do one thing and then begins doing other things as well.
Downloading files, whether MP3's or other forms of software, should be done with care and not "automatically." The placing MP3 files on the web for easy downloading does not abrogate copyright rules, however. Automated operation of Napster will violate any copyright restrictions that apply. Although the creators of Napster recognize this danger and suggest using Napster with caution, the program itself behaves blindly. This is not smart!
Running Napster also creates a number of privacy and security concerns. The creators of napster do not describe what types of antivirus protection they have built in - so it's quite possible that napster will happily infect a whole network. Napster also does not describe the security features that prevent it from publishing other files on the user's computer
Future: The Next Generation Internet.
The "growth spurt" we've observed this semester raise important questions
for planning. Will next year's growth be more like the historic 40%, more like the
recent 100%, or be an more dramatic 200% growth ? Predicting what's in store might
benefit from looking at some emerging technologies.
The long term success of the network services at UVM will depend as much on developing
intelligent and sensible use of the network as it will on technological enhancements.
The coming era of digital convergence with global digital libraries, interactive
collaborative environments, and network appliances "so easy to use that they
are invisible."
As mentioned at the beginning of the article, UVM has contracted for an upgrade
in it's internet service - both in terms of bandwidth and in terms of quality of
service. These improvements will provide relief from the current congestion but also
encourage the growth of new services.
Upgraded Campus Backbone
As part of our NSF vBNS (very high speed Backbone Network Service) project, UVM has
upgraded the campus backbone network to gigabit speeds - a cross campus speed that
is faster than the speeds inside your own computer (at least for the time being :).
Conserving Bandwidth
On November 7th, UVM installed a "caching server." This server keeps local
copies of frequently accessed files and automatically shares incoming broadcast "streams."
A file retrieved from the "internet" at internet speeds becomes available
from the "intranet" at gigabit speeds. The cache server decreases external
bandwidth needs while increasing internal access.
Increasing Bandwidth
Our increased bandwidth will come in two parts. One is for "commodity"
internet service ("internet1" if you will). This will increase from our
current 4.5 Mbps service to an approximately 15 Mbps service. The second is for vBNS
internet service ("internet2"). This will be a 45 Mbps service connecting
UVM to about 150 other research universities and national laboratories.
Enhanced Architecture
The new commodity internet service will be Bell Atlantic BBNPlanet services and with
Hyperion's Adelphia service, both with a local "point-of-presence" (POP).
This has several advantages.
- connections to many Vermont institutions will immediately benefit since they will be "closer" - usually only a "hop or two" away, rather than the "10 or 12" hops we currently observe.
- out-of-state service will improve because Bell Atlantic has a significantly higher capacity bandwidth locally than our earlier provider.
- our service will be more easily upgraded - via "reprogramming" so that future growth spurts won't have as great an impact on the campus. Eventually this will evolve into a bandwidth on-demand service.
- experience with Internet2 will allow us to begin deploying "Quality of Service" technologies that will be used to better manage our commodity services.
These improvements, however, are almost certain to open the way to even more interesting
networking applications, many of which are already appearing on campus. Helping to
understand how these will impact the "next generation network" at UVM and
globally is one of the opportunities we can all participate in. Below is a list of
some popular new and developing uses for the network. Anyone interested in exploring
these should contact me or other CIT staff for help in understanding the network
impact as well as developing strategies to improve usability.
Interactive Chat
The net has a long history of supporting one-on-one conferencing. "Talk"
was a popular program on the 1980's era's Decsystem 2060 and VAX. It is still popular
in the "zoo.' Similar programs such as IRC ("Internet Relay Chat"),
AIM ("America Online Instant Messenger"), ICQ ("I seek you"),
and many others are available on PCs. These modern programs use icons and avatars
to represent the participants in a graphically interesting "virtual reality."
Generally "chat" programs are net friendly; data is usually exchanged at
"typing speed." Their slow, leisurely pace, however, usually mean that
people spend more hours in chat than they would in email.
Computer Games
Computer games, while visually intense, are also, for the most part, net friendly.
These games communicate with each other by exchanging coordinates (positions, velocities)
for the players, and the game software constructs the scene on the fly. One-on-one
games, such as the Internet Chess Server, have almost no bandwidth requirement. In
multiplayer battle games, however, the more data is exchanged more frequently. Still,
these games are generally "well behaved" and programmed for good performance
in a modem environment.
Web Cameras
Web cameras are increasingly popular - particularly as an adjunct to a chat room
environment. A typical cam produces a 20 Kb image file once every 30 seconds, a refresh
rate that fits within the demands of a 28.8 modem. Last year, a UVM student was a
participant in the WebDorm Community. Networks like the WebDorm, however, have off
campus hosts providing connections to the users.
Video Clips
UVM has already begun experimenting with the delivery of video clips. These experiments
include broadcast material such President Ramaley's Inaugural Address, Michael Hopkins
"String Pedagogy Notebook", "Dr. Tuna" Snyder's Debate Forum,
and private, course restricted material such as that offered in the School of Nursing.
Streaming Audio and Video
MP3 files and Video clips are generally downloaded before playing, a slow network
means that you have to wait before the fun begins. Often, however, this tests the
patience of the user. To provide more immediate satisfaction, then, many sites have
implemented "streaming" servers. The audio or video is presented to the
network so that it can be played as it is being downloaded.
Radio and Television stations routinely use streaming technology such as RealAudio,
RealVideo, and QuickTime. NPR (National Public Radio), BBC (British Broadcasting
Corporation) and UVM's own WRUV radio station have been "live" for several
years. President Ramaley's 1999 "State of the University Address" was broadcast
both live and "on disk" using streaming technology.
Streaming technology is also used with the UVM video applications and is partly supported
by an equipment grant from Apple Computer and a software grant from Real Systems.
Interactive Video
Interactive video is the 1990's version of the 1960's video phone. Unlike the webcam
which operates at 1 "frame" per 30 seconds, interactive video attempts
to operate at 5 to 15 video frames per second. In the Internet1 setting, interactive
video was generally very choppy; it often required that a participant "use your
imagination" to create a video sensation. As the Internet2 era develops, interactive
video is becoming common place, and many conference participants are now presenting
"via video" rather than live.
At UVM, the World Debate Institute is arranging a number of live, multiparty, participatory
debates. The first debate is being scheduled for UVM and Cornell University sometime
in December.
Research Opportunities for Undergraduates
Most of the applications listed above are "still experimental" and provide
a lot of room for learning. Even the somewhat notorious Napster program contains
a gem of a very powerful idea that should be systematically tested in a more controlled
environment. Sometimes things have to be "a bit broken" for them to be
improved.
The Cooperative Association for Internet Data Analysis (CAIDA) based at the University
of California San Diego Supercomputer Center (SDSC) is an NSF sponsored project to
coordinate a wide variety of internet related developments. Many of the projects
include special procedures for supporting undergraduate contributions to network
research activities.
The UVM vBNS project investigators, Steve.Cavrak@Uvm.Edu,
Charles.Colburn@Uvm.Edu, and David.Dougherty@Uvm.Edu all invite students and faculty
to contact us for possible projects and activities that will help us successfully
move to the next generation internet.
Strategic Change and the Networking Future
What will be UVM's network a year from now? Five years from now? As many of us
at UVM are beginning to learn, the network grows because we grow. UVM's Strategic
Change process appropriately highlights technology as enabling us to create our own
future. If you have suggestions, concerns, or questions about networking at UVM,
the folks at CIT are eager to chat with you - electronically or live, perhaps even
over a cup of coffee or tea. Contact us at cit@uvm.edu.