computer science context. UAB'S undergraduate specialization in Telecommu- nications and Computer. Networking includes a four- course sequence: CS 433.
A COMPUTER SCIENCE UNDERGRADUATE SPECIALIZATION IN TELECOMMUNICATIONS AND COMPUTER NETWORKING *
Anthony C. L. Barnard Barrett R. Bryant Warren T. Jones Kevin D. Reilly Department of Computer and Information Sciences University of Alabama at Birmingham 1300 University Blvd. Birmingham, {barnard,
AL 35294-1170,
bryant,
jones,
that university curricula appropriIt k important ately reflect the rapid advances taking place in computer science ([ Fole88], [Hart92]). The area of telecommunications and computer networks is undergoing particularchange.
A conference
sponsored
(UAB)
by BellSouth
expressed an urgent need for educational programs keep up with the rapid advances that have occurred this area. paper
we use the phrase
offers
an undergraduate
program
based upon
ACM Curriculum ’91 [~ck91], leading to the Bachecore courses provide lor of Science degree. Traditional students with the fundamental design principles of the software and hardware of computer systems, the use of modern programming languages, and operating systems and equipment. Additionally, students have been able to specialize in one of two tracks: Information Systems, or Scientific Computing. In 1993 we instituted a third
Foundation [Jone90] called attention to the importance of telecommunications to the computer field and the need to emphasize this area in coursework and laborate ries at both the undergraduate and graduate levels (see also [Jone91]). Similarly, an NSF report [N CR192] on research priorities in networking and communications
In this
edu
The Department of Computer and Information Sciences at the University of Alabama at Birmingham
INTRODUCTION
ly rapid
U. S. A.
reilly}@cis.uab.
track
to complement
the activities
for Telecommunications
to in
is largely
a graduate
graduate
program
Education study
center)
embedded
of the UAB
Center
and Research (which with
a strong
in a traditional
under-
computer
science context.
“telecommunica-
UAB’S undergraduate nications and Computer course sequence:
tions and computer networking” in a broad sense, to include information networking and distributed computing, especially heterogeneous client-server applications.
specialization in TelecommuNetworking includes a four-
CS 433. Telecommunications
and Computer
Net-
works * This work was supported in part by National Science Foundation Instrumentation and Laboratory Improvement Grant Inc.
DUE-9351476
and a donation
from FTP
CS 434. Internetworking
Software, CS 435. gramming
Network
CS 436. Advanced
Permission to copy witbout fee all or part of this material is grantad provided that the copies are not made or distributed for direct commercial advantage, the ACM copyright notice and the title of the publication and its date appear, and notice is given that copying is by permission of the Association for Computing Mscbinery. To copy otherwise or to republish, rerfuires a fee andlor specific permission. SIGCSE ‘SS 2/9S Philadelphia, PA USA e199S ACM 0-09791 -757-X9WO002.... SO.SO
and
Distributed
Information
System
Pro-
Networking
In the sections which follow, we will describe curriculum and conclude with a discussion of experiences with the curriculum. More details about the specialization may be found at
the our
324
http://www.cis. spirit
of ACM
uab.edu/info/dept/courses/. Curriculum
for the “knowledge
In the a proposal
‘91, we begin with
units”
which
comprise
through
TN22.
CS 435 covers TN23
436 fills in the wireless
this special-
and high-
through
TN25.
performance
CS
aspects
of TN 13, and covers TN26.
ization. LABORATORIES KNOWLEDGE CATIONS
UNITS AND
IN
COMPUTER
At
NETWORKING
UAB
ratories, We propose that this field be composed lowing knowledge units: TN: Telecommunications and Computer (approximately 144 lecture hours)
of the fol-
History and Overview of Telecommunications and Computer Networking (4 hours)
TN2:
Protocol
TN3: TN4:
Model (3 hours) Services and Primitives Protocol Specification,
TN5:
Theoretical
TN6: TN7:
(2 hours) Transmission Media and Modes (4 hours) Switching Systms, including standard Telephone and Narrowband ISDN (5 hours)
TN8:
Cellular
Performance
(2 hours) Verification,
client;
and
[Tane96]).
Protocols
TN23-TN25. AND
NETWORKS
The
course
generally
pursues
a bottom-up
After
mid-term
the course
includes
a “hands-on”
Local Area Network (LAN) laboratory, nominally of Transmission Control Prototwo hours per week. col/Internet Protocol (TCP/IP) is emphasized, which involves bringing in material from [Come95], since the
Connection
material
(6 hours)
TN15: Network-Layer
by an
study, following the 1S0 Open Systems Interconnect (0S1) model. Layers 1, 2 (MAC sublayer), 3, and 4 are emphasized.
for Shared Channels
Service;
by two laboin part
CS 433 is the first course in the sequence and includes portions of knowledge units TN1-TN16, concentrating on local-area networks and using (Tane89] as a textbook (shortly to be replaced by the 1996 edition
and Communications
and Unreliable
funded
TELECOMMUNICATIONS
COMPUTER
(3 hours) TN13: IEEE 802 Standards and High-Speed Extensions (10 hours) Management
is supported
equipment
this lab supports
CS 433 Communication
Satellites (2 hours) TN9: Framing and Error Control (3 hours) TN 10: Flow Control, including Sliding Window (3 hours) TN1l: Data-Link Layer Protocols (3 hours)
TN 14: Reliable
specialty
datagrams). Lab B contains two networked Sun workstations, one configured as a server and the other as a
(4 hours)
TN12: Access Protocols
this
containing
Software’s LANWatch monitor; students normally work in pairs at these machines. The other two PCs normally run aa server/routers, using Novell NetWare 4.01 (which includes the capability to route Internet Protocol (1P)
and the 0S1 Reference
Basis of Data
Radio
EQUIPMENT
NSF ILI grant. Lab A, which supports knowledge units TN2-TN22, contains ten networked Gateway 2000 PCs. Eight of these normally”run as workstations or run FTP
Networking
TN1:
Layering
AND
TELECOMMUNI-
port
(10 hours)
extends
TN16: Transport-Layer Protocols (10 hours) TN17: Bridging between Networks (2 hours) TN18: Internet Control and Management, including MIB/SNMP (8 hours)
on TCP/IP
the lab.
The
in [Tane89]
is not adequate
laboratory
into the final
component
to sup-
of the class
examination.
Although TCP/IP was developed as an internetworking protocol suite, wide-area networks and internetworking
are de-emphasized
in CS 433.
TN19: Static and Dynamic Routing (10 hours) TN20: Directory (Name) Service (4 hours) TN21: File Systems and Transfer, Remote Login,
1ne specmc laD sessions are:
and E-Mail (8 hours) TN22: Security, Cryptography, (4 hours)
Students get their first “hands-on” experience with an Ethernet LAN, connecting 10baseT cables and
TN23: Protocol
Compiling
and Firewalls
loading
(6 hours)
TN24: Distributed Systems (10 hours) TN25: Programming Client-Server Systems TN26: Broadband
ISDN
Ethernet/Address
and ATM
(10 hours)
(8 hours)
These knowledge units are distributed across the four courses. CS 433 focusses on TN1 through TN16. CS 434, which specializes in TCP/IP, fills in the relevant details
in TN1O,
TN15,
and TN16,
325
TCP/IP
Protocol
software
(ARP).
layers.
Ac-
tivities include: testing connectivity using “ping”; examining structure of frames using LANWatch monitor (including decoding hexadecimal representations of frames); examining the ARP cache. This experience emphasizes the multi-level encapsulation of messages within an 1P datagram and of the 1P datagram within an Ethernet frame.
2. Internet
and covers TN17
the various
Resolution
Protocol
(IP)/Internet
Control
Mes-
sage
Protocol
(ICMP)/User
(UDP)/’Ikivial
Datagram
File Transfer
Protocol
Although
Protocol
Students set up a PC as a TFTP-server and copy a 1.6 MByte file from the server to a client workstation. Activities include: measuring time taken for transfer; examining internal details of the frames using LANWatch. This shows encapsulation of the TFTP
message within
a UDP
datagram,
datagram within an 1P datagram, gram within an Ethernet frame.
Netware
the UDP
and the 1P data-
Protocol (IP)/Transmission (TCP)/TelNet.
ing, etc. ) (option
with
establishment, attention
negotiation,
44 File Transfer
Control
Pro-
of TFTP and FTP, required for transfer
Cs
434
sequence
also to TelNet
number-
ered up.
activities
comparing
2. Static
emphasize
Exams
include
a
Bridges
Between
characteristics
Students
units
Routing
use TFTP
to transfer
a 1.6 M-
Between
of the same file within a in CS 433 lab session 2. Two Networks.
1P router.
This
es, subnet
masks and default
stations.
involves
The router
assignment
has static
of 1P address-
routers
in the work-
routing
enabled
and
Routing Information Protocol (RIP) disabled. Only the direct connections are needed in the routing tables (no indirect connections exist with only two segments). Students ping the target on the “other” network, and use LANWatch to observe the sequence and internal details of frames exchanged, noting that the hardware destination addresses and 1P destination addresses are different for the first time (the difference between the immediate destination and the ultimate destination). Students a-
covered. In this second course the weekly lab sessions are again central, this time lasting the entire course. knowledge
Networks.
Again we begin with two disconnected Ethernet segments, which are then connected using a single
including comparison of times of the 1.6 MByte file.
from
and the Final
time required for transfer single network, measured
The title of CS 434, “Internetworking,” signals that the emphasis is on a connected system of at least two net works. Connection by means of bridges or routers is
mainly
434
Byte file across the bridge, measuring elapsed time for transfer. This can then be compared with the
INTERNETWORKING
The course draws
CS
This lab begins with two disconnected Ethernet segments, which are then connected using a transparent bridge. Using the LANWatch monitor, students observe functioning of the bridge, including the “learning” process when the bridge is first pow-
(FTP).
frames;
and
lab sessions are:
1, Transparent
Students set up a PC as an FTP server, and copy the same file as in Lab Session 2 to a client workstation. Activities include: measuring time taken for transfer; using LANWatch to study sequence of frames exchanged and the internal composition of representative
the Mid-Term
The specific
etc.)
Protocol
433
4.01.
Both
Students set up a PC as a TelNet server, and establish cent act from a client workstation, using LANWatch to observe sequence of frames exchanged; detailed internal composition of representative frames with emphasis on TCP activities (connection
CS
lab component.
3 Internet tocol
both
TCP/IP, they are not exclusively TCP/IP courses. In the middle of CS 434 there are lectures on the Xerox system, XNS, which formed the basis for the Novell systems that dominate the LAN world. In the lab the students have the opportunity to work with an IPX internet constructed with two server/routers running Novell
(TFTP).
TN17-
TN22, and fills in TCP/IP details from TN1O, TN15 and TN 16. Again a bottom-up inside-out approach
gain use TFTP
is used. In the lectures, [Come95] is used, although the order of the material is varied considerably to mesh with the lab semions.
taken for transfer across the router with the time obtained in lab session 1 for file transfer across the bridge.
this time
3. Static
In the labs, internetworking is introduced first as the connection of Ethernet segments entirely within the
The
physical lab (this allows us to take liberties such as deliberately introducing routing loops). In later lab ses-
campus
network,
and finally
a 1.6 MByte they compare
and Dynamic lab internet
file,
but
the time
Routing. is now expanded
to three
Eth-
ernet segments, connected by two routers. Additional entries are made in the static routing tables for the indirect connections (via a second router).
sions the students “escape” from the physical confines of the lab, first to the CIS Department network, then to the UAB
to transfer
across the router;
Students
out to the Inter-
changed
net. In the last lab sessions the students use Netscape to obtain multimedia information over the Internet.
use LANWatch when
pinging
to study targets
the frames
ex-
across two routers.
At first, a deliberate mistake is made, omitting necessary routes from the tables; this results in
326
“network unreachable” ICMP messages, which are studied by the students. Addition of the necessary routes establishes connectivity. routing is disabled and RIP enabled. LANWatch router,
to observe
RIP
more distant
routes
serve dynamic
from each other.
addition
4. “Host
Redirect”
Complex
Network Management Protocol (SNMP) and the Management Information Base (MIB).
when physi-
Students examine the management information base in their workstations, and see how this can be remotely monitored using SNMP.
Internets.
8. Gopher
In the TCP/IP implementation that we use (Novell’s LAN Workplace for DOS), workstations do not participate is a mechanism namically:
may send an ICMP
“host redi-
this activity with LANWatch and LWPCON. As a final exercise in building internets, we assemble an internet consisting of five Ethernet segments and two routers. At the hardware level, “null-modem” cables are used for two of the networks, so that students see this possibility y. At the network level,
Cs 435 NETWORK AND SYSTEM PROGRAMMING
routing
tables
sizes the upper layers of the 0S1 reference model, and gives students their first opportunity to program appli-
of the
cations to run in a distributed computing environment. The knowledge units covered by this course include por-
routers.
5. Exploration
of Novell
Netware
tions of TN2, TN4, TN1l, TN12, TN15 and TN16, and the entirety of TN23-25. Since the material covered in CS 435 is heavily influenced by programming and operating systems considerations, the subject matter also coordinates nicely with other courses within the UAB
4.01.
An internet is established with two Novell LAN’s, each with a NetWare 4.01 server and four workstations; these two LAN’s are connected using the IPX
routing
capability
of the servers.
eral exploration of Novell on a carefully-structured vell file system
After
a gen-
undergraduate
LAN’s, students embark investigation of the No-
and its security,
controlled
6. Domain
(DNS).
and use LANWatch
to observe
course.
the process Sun Solaris systems form the core of the laboratory environment. Student exercises are mainly rooted in illustrations in [B1oo92]. For a DCE context there
of querying the domain name server to determine the corresponding 1P address. With connection to the outside world established, students can ping a machine anywhere in the world, and use LANWatch to measure the time taken for the round trip. The students use TRACEROUTE utility to determine ty, using
path
taken
LANWatch
by ping to Purdue to study
in-
Directory Service (a naming service), time service mechanics and security, are all covered using [Rose93]. ONC analogs from [B1oo92], are also covered. Distributed file systems are cited as premier examples of clientserver and remote procedure calling. Demonstrations form an important part of the classroom portion of the
This network lab reverts to a single Ethernet segment, but now is connected by a bridge “through the wall” to the CIS department network. Students ping one of the CIS department computers by name,
a survey of the complex
teracting software that makes up a distributed programming environment. The Open Software Foundation’s Distributed Computing Environment (OSF DCE), Cell
of FTP).
Name Service
curriculum.
The course begins with
by the
lab instructor’s adding “rights” incrementally (this provides a comparison to the relatively unsophisticated security
DISTRIBUTED
Completing the bottom-up development of networking outlined in the previous two courses, CS 435 empha-
students must assign suitable 1P addresses, subnet masks, and default routers in the workstations, as in the static
Gopher and wide variety in the world World-Wide
Web ( WWW), including instruction on Hyper-Text Markup Language (HTML); students use HTML to construct their own WWW home pages.
rect” message to a workstation, which will note this information in its routing table. Students observe
well as entries
and Netscape.
Students are instructed in the use of Netscape, and are able to obtain a of information from sources anywhere using the Internet, Emphasis is on the
in the RIP activity. However, there for workstations to learn routes dy-
Routers
Stu-
7. Simple
ob-
made, and deletion of old are deliberately broken.
and More
works.
each
“learn”
Stduents
of new routes
cal connections are first routes when connections
from
automatically
how TRACEROUTE
dents also use the FINGER utility, and use FTP to obtain a sample Request For Comments (RFC) from the InterNet Information Center.
Then static Students use
broadcasts
and see how routers
and understand
the frames
is similar material in [Shir94]; this contains examples, such as vector addition, that when slightly modified can be run under Solaris or Linux. OSF and ONC flavors thus dominate, but side commentary is provided on 0S1
Universi-
and the Windows-NT
involved
327
variant.
Both
the IDL
and ONC
rpcgen-based protocol ers are discussed.
definition
languages
The ONC system for student projects.
is used for class assignments
tions and the electrical power utility. We have made several presentations about our curriculum to local groups,
and compil-
which and
Some students select ambitious projects, e.g. running an example from [Rose93] on a Linux port of DCE. Other students prefer the safer ground close to examples demonstrated in the classroom,
e.g.
remote
and directory
database
listing,
query/update,
or distributed
remote
image
all welcomed
file
[B1oo92]
J. Bloomer,
INFORMATION
networks
-
wireless
LANs
switches Ethernet;
[Fole88]
J. Foley, ed., “Report of the Computer Science Workshop: Undergraduate Computer Science Education”, Report on the National Science
(IEEE
Using RPC,
1992.
Intern etworking with TCP/IP. D. Comer, Protocols and ArchiVolume I: Principles, tecture, 3rd cd., Prentice-Hall, 1995.
on
802. 11), non-blocking Ethernet peting standards for 100 Mbps
it was
(Come95]
not covered thoroughly in the earlier courses, such as the following topics from knowledge units TN13 and TN26: Local-area
Programming
Power
& Associates,
O’Reilly
A preliminary version was taught in Spring 1995 as a “special topics” course, but CS 436 will not be formally offered until Spring 1996, so that its content is still somewhat fluid. Clearly, it should include areas
●
and thought
REFERENCES
processing
(based on [B1oo92]). CS 436 ADVANCED NETWORKING
the information
a significant contribution to the local and regional needs for networking expertise. Therefore, we believe that the specialization has been successful in meeting its objectives.
[Hart92]
and com-
Foundation
Disciplinary
Undergraduate
J. Hartmanis The
and
Future:
H. Lin,
A Broader
er Science
Workshops
Education,
1988.
eds.,
Agenda
Computing for
Comput-
National
and Engineering,
Acade-
my Press, 1992. ●
●
Metropolitan-area networks - IEEE 802.6 (Dual Bus Distributed Queue) and Switched Multimegabit Data Service (SMDS)
[Jone90]
lenges and Opportunities,” (Invited PreBelLSouth Foundation Conference sentation)
Wide-area networks - frame relay as an out.mowth Optical Network (S~NET) of X.25, Synchronous and cell relay (Asynchronous
‘llansfer
on Telecommunications:
Mode)
Students
Equipment is on order to support a lab experience wireless Ethernet LANs. However, it is far from
with clear
four
respectively.
times,
Thirteen
enrolling students
Networking
[Rose93]
[Shir94]
importance
J. Shirley, Writing
W. DCE
sociates, [Tane89]
[Tane96]
the growing
Rosenberry,
& Associates,
CONCLUSIONS specialization
W.
Kenney
DCE
of computer
in response networks
[Tuck91]
to
in our
328
G. Fisher, O’Reilly
Guide to D. Magid, O’Reilly & As-
Applications,
1994. Computer
A. S. Tanenbaum,
A. B. Tucker, et. the ACM/IEEE-CS Report
Commun.
and
Applications,
Hu and
A. S. Tanenbaum, ed., Prentice-Hall,
Force
geographic area, as communicated to us by local financial institutions, hospitals, BellSouth Telecommunica-
Research
1993.
cd., Prentice-Hall, was established
1990.
1992. D.
Understanding
435, and seven took the preliminary version of CS 436. The complete sequence has been completed by 6 students, all of whom will be graduating in the next academic year. We expect to be able to rotate 32 students per year through the entire sequence, out of a senior student body of approximately 50 students. That is, most students in our B. S. program will be graduating with this specialization.
The
and Communications
and Infrastructure,
CS
College
Age,
Research Priorities in Networking and Communications, Report to the NSF Division of
109 and 66 stuhave taken
Connecting
Information
[NCR192]
Over the past two years, CS 433 and CS 434 have dents,
The
W. T. Jones and F. M. McGuirt, Telecommunications and Computer Science: Two MergACM SIGCSE Bulletin .23 ing Paradigms, (Dec. 1991), 13-22.
ENROLLMENT
each been offered
To
[Jone91]
how to offer students a significant laboratory experience relevant to metropolitanand wide-area networks. STUDENT
W. T. Jones and F. M. McGuirt, “Computer Science and Telecommunications: Chal-
ACM
Networks,
2nd
Networks,
3rd
1989. Computer
1996. al. “A Summary of Joint Curriculum Task
Computing Curricula 1991,” 34, 6 (Jun. 1991), 69-84.