Presentation relay on how to design Local Area netwok

1. MIS 760
DATA COMMUNICATIONS
Network Design

2. Introduction
 Issues in the design of a Local Area Network
(LAN):
 Needs analysis – What do the users need from
this network?
 Technological design – What devices are needed
to properly support the demands that will be put
on the network?
 Cost assessment – Can I afford it?!

3. Looking For Hardware?
 CDW:
 www.cdw.com
 Useful catalog of basic and professional grade
networking equipment

4. White’s LAN Example
 What type of system will interconnect
twenty workstations in one room and 15
workstations in another room to a central
server, which offers:
 Internal e-mail
 A database that contains all customer
information
 High quality printer access

8. Nomenclature
P1 Typical PC (1.5GHz)
P2 High Traffic PC (2.8GHz)
PR Printer
FS File Server
EF Email/Fax Server
M Modem
H Hub
SW Switch
R Router

9. An easier way to draw (ALT I)
P1 P1SWSW
x16 x12
Technical
Services
Administrative
Services
Cat5e
Cat5e
Wiring
Closet
FO
FS
FO
Maintenance
Room
P1 P1PR PR
x4 x3
Cat5e
R
T1

10. An easier way to draw (ALT II)
P1 P1SWSW
x20 x15
Technical
Services
Administrative
Services
Cat5e Cat5eCat5e
DS
FO
Maintenance
Room
SW Cat5e
MS
FO
PR PR
x4 x2
Cat5e Cat5e
DSL

11.  To identify each connection between sites:
 d = distance of the connection (usually shown in either
miles or kilometers)
 s = security level (high, medium, low, or none)
 du = duplexity (full duplex, half duplex, or simplex)
 dr = data rate desired (in bps)
 l = latency, or acceptable delay time across the network
(usually in milliseconds, or ms)
 QoS = Quality of Service (CBR - constant bit rate, VBR -
variable bit rate, ABR - available bit rate, UBR - unreliable
bit rate, or none)
 De = Delivery rate (throughput percentage)
Network Modeling

13. Summary
 In order to construct a LAN, you must:
 Carry out a needs analysis, in order to develop a
technological design, and cost assessment
 You need to know the needs of the company before you
can design the LAN, but not every company can afford
the LAN they need!
 The designs should:
 Show the logical connection of users
 Show the support for traffic between nodes
(connectivity maps)
 Allow a technically-competent technician to install the
physical LAN layout

14. Design 1

15. Overview
 Designing a LAN for a small company
 Needs analysis
 Technology design
 Cost assessment

16. Design in threes
1. Cheapest alternative:
 Meets only the core requirements, but
cheap
2. Most likely:
 Meets critical requirements close to the
stated budget
3. Gold-plated
 Takes advantage of the best of available
products

17. Nomenclature
P1 Typical PC (1.5GHz)
P2 High Traffic PC (2.8GHz)
PR Printer
FS File Server
EF Email/Fax Server
M Modem
H Hub
SW Switch
R Router

18. Design 1-1
H
FS
M
Internet (ISP)
Shared Ethernet
P2
P2
P1
P1
PR
6 Consultants
1 Assistant
1 Manager
1 Assistant

19. Design 1-2
SW
SW
Travel Consultants Management/Clerical
Internet (ISP)
M
FS
EF
P2
P1
P1PR P2
P2
P2 PR
1 Manager2 Assistant
6 Consultants

20. Design 1-3
R SWSW
Travel Consultants Management/Clerical
Internet (T1)
FS
EF
P2
PR
P2
P2
PR
FS
P2
PR
P2
P2
FO FO
6 Consultants
2 Assistants
Manager
2 Printers

21. Decision time!
 Which one will work?
 Which one works best?
 Which is best value for money?
 Therefore, which one would you
recommend?

22. Design 2

23. Overview
 Designing a LAN for a medium-sized
company
 Needs Analysis
 Technology Design
 Cost Assessment

24. Issues with multi-floor designs
 Can design top-down (backbone to
segments), or bottom-up (segments to
backbone). Will probably need:
 Backbone to connect the floors
 Wiring closet to store connection devices
 At least one Router
 A server farm in a secure room

25. Example
Wiring Closet
Server
farm
Floor 2
Floor 1

26. Design in threes
 Cheapest alternative:
 Meets only the core requirements, but cheap
 Most likely:
 Meets critical requirements close to the stated
budget
 Gold-plated
 Takes advantage of the best of available products

27. Design: Floor plan
Floor 4 Floor 5
Attorneys+Legal Sec.Reception+Others
Recep-
tion
Clerical
Legal
Sec. Partners/
Associates
Partners/
Associates
Network
Room
Waiting

28. Design: The segments
5th
4th4th Floor
Wiring Closet
5th Floor
Wiring Closet
Server
Farm
30 Attorneys
+ 10 Legal Sec.
10 Legal
Sec.
6 Clerical
+ Office Mgr

29. Design 1
5th
4th
R
P1
PR
SW
T1
FS EF
SW
P1
PR
10 Legal Sec.
6 Clerical
1 Mgr.
24 port
48 port
X3
20 Attorneys
10 Legal Sec.
P2

30. Design 2: 4th Floor
SW
5th Floor
SW
P1
PR 6 Clerical
1 Mgr.
SW
P1
PR
10 Legal Sec.
8 port
16 port
8 port
X2
X5
X7

31. Design 2: 5th Floor
R
4th Floor
T1
SW
SW
16 port
FS EF
8 port
P2
X5
8 port
SW PR
20 Attorneys
X4
SW
P1
PR
10 Legal Sec.
8 port
X2
P2
X5

32. Design 3: 4th Floor
R
5th Floor
SW
P2
PR
6 Clerical
SW
P2
PR
10 Legal Sec.
8 port
16 port
8 port
X2
X6
X5
P2 PR Mgr.
X2
FO
FOFO

33. Design 3: 5th Floor
R
4th Floor
DSL
SW
SW
16 port
EFFS
8 port
LC
X5
8 port
SW PR
20 Attorneys
X4
SW P2
10 Legal Sec.8 port
X2
P2
PR
X5
AP
FO
FO
FO

34. Decision time!
 Which one will work?
 Which one works best?
 Which is best value for money?
 Therefore, which one would you
recommend?

35. Part 3
Cost Assessment

36. Costs
 Can be radically different depending on the
actual devices to be used (hubs, switches,
etc., etc.)

37. Summary
 For a medium-sized company LAN:
 Extra issues in the size of the network and the
fact that it is split across two floors
 Will need a backbone connecting the floors, and a
secure room to house the server “farm”
 Most traffic will be concentrated on the Legal
Secretaries