CP2023
Computer Networks
Dr. Ian Coulson
Assessment 1
Colin Hopson
0482647
19th May 2006
i
Contents
1
2
3
4
5
6
7
Introduction............................................................................................................1
1.1
Overview........................................................................................................1
1.2
Assessment Report Requirements and Evaluation ........................................2
Proposed Solution ..................................................................................................3
2.1
Preliminary Physical Topology......................................................................3
2.2
Conclusive Physical Topology ......................................................................4
Subnet Analysis .....................................................................................................5
3.1
Subnet Calculations .......................................................................................5
3.2
Inventory and Installation ..............................................................................6
3.3
Costing and Flexibility.................................................................................10
Conclusion ...........................................................................................................11
Notes ....................................................................................................................11
Reference A : Internet Research Listings ............................................................12
Reference B : Published Research Material.........................................................13
ii
1 Introduction
1.1 Overview
It is given in the assessment criteria that the IP address 190.123.36.0/22 is allocated to
the network infrastructure. From this we can derive that we would use a Classful
Class B network as shown in the diagram below.
High Order Bits
Octet in Decimal
00000000→01111111
10000000→10111111
11000000→11011111
0→127
128→191
192→223
Address Class
Class A
Class B
Class C
However, to compensate for wasting IP addresses, but in order to retain some host
addresses for future expansion, we subnet the host section of the given IP address
using the Network Classless Scheme (CIDR). This method helps to allocate a certain
number of host IP addresses to each subnet as well as utilise a subnet routing scheme.
Firstly, it is necessary to work out the quantity of subnets and the number of hosts
required on each subnet. This can be deciphered from the Assessment Report
Requirements. By grouping rooms to the similar number of hosts from each physical
location, we list the chart below.
Location of Building
Room Desc.
First Subnet
MU Building
Staff Offices
Second Subnet
MU Building
MU023
MU Building
MU029
MU Building
MU032
Third Subnet
MU Building
MU011
MU Building
MU107
MU Building
MU404
Fourth Subnet
MU Building
Consult Room 1
MU Building
Consult Room 2
Fifth Subnet
Telford Building
Telford Lab 1
Telford Building
Telford Lab 2
Totals: 5 Subnets/350 Workstations
Number of Hosts
70 Workstations (plus networked printer/s)
40 Workstations (plus networked printer/s)
40 Workstations (plus networked printer/s)
40 Workstations (plus networked printer/s)
20 Workstations (plus networked printer/s)
20 Workstations (plus networked printer/s)
20 Workstations (plus networked printer/s)
10 Workstations (plus networked printer/s)
10 Workstations (plus networked printer/s)
40 Workstations (plus networked printer/s)
40 Workstations (plus networked printer/s)
It is assumed that each consultancy room has 10 workstations and require an internet
connection through the MU building. In calculating costs for installation, room sizes
are estimated and equipment costs are averaged by current and collated internet prices
as detailed later.
1
1.2 Assessment Report Requirements and Evaluation
Your task is to design the network infrastructure for the school of computing as if it
was separate from the rest of the university. The design is for MU building and 2 labs
of 40 machines, each at Telford. The rooms MU023, MU032, MU029, have 40
workstations and MU107, MU011, MU404 have only 20. There must be a link between
MU building and Telford, and also out to the internet from MU building. There are also
70 staff that are networked on a staff network and a small separate consultancy group
based in 2 rooms with 10 staff allied to university but not officially part of it.
You must supply a written report for your design that will include:
1.
2.
3.
4.
5.
6.
a diagram of your proposed physical topology;
any subnet calculations and listings;
an inventory of equipment in the system;
costing for all necessary equipment and estimates of any installation costs;
Listing of services from the ISP and costings for them.
A brief explanation of how your design is flexible enough such that further
scaling up of network requirements can be accommodated.
7. The usual sections in a written report such as introduction etc.
SCIT has been allocated the IP address of 190.123.36.0 /22
This is an individual piece of work and you must not collude with any other person, or
plagiarise your work.
Evaluation criteria
Grade A
An excellent standard of work, a clearly presented report, with valid
solutions to all parts of the assignment. A good standard of written
English and all work referenced
Grade B
As in A, but with minor errors in the solution proposed, or with only an
adequate standard of presentation. The report should show a good
understanding of network technology applied to the current situation and
a good understanding of the benefits that the proposed system would
bring.
Grade C
The report substantially addresses the requirements, but has omissions or
errors or poor presentation in some respects.
Grade D
The minimum pass grade will include a valid attempt at all parts of the
report, but some aspects are incorrect and/or incomplete or a good attempt
at some of the tasks with others poorly attempted or very poor
presentation, or not in report format.
Grade E
The work is seriously lacking in key aspects, the proposed solution and
evaluation of the current situation demonstrates a fundamental lack of
understanding of the issues involve.
Grade F
No serious attempt made.
2
2 Proposed Solution
2.1 Preliminary Physical Topology
Pictured below is a basic physical topology of my proposed networking solution. In
conjunction with the subnet grouping produced earlier, we can deduce the following;
One student access zone at Telford
One staff access zone at Wolverhampton
One consultancy access zone at Wolverhampton
Two student access zones at Wolverhampton
3
2.2 Conclusive Physical Topology
Pictured below is a structured topology of my network solution, along with devised
zones and hardware assemblage.
4
3 Subnet Analysis
3.1 Subnet Calculations
The chart below shows the binary representation of the IP addresses - right-most
octets. Here we can use the 2 static network octets plus extend the network portion
using 6 bits from the host’s left octet (i.e. 190.123.36.0/22 = (8+8+6) = 22 ).
However, by using this ‘sub-netting’ method it is essential to decipher a subnet mask
as this, along with the network address, specifies multiple class subnets for one
address. The amount of bits used in the right-most octet is determined by the quantity
of hosts required on each subnet.
Additional Network Portion (Left Host Octet)
128
64
32
1 → 2 → 3 →
16
8
4
2
4 → 5 → 6
{ 7
Right Host Octet
1 128
64
8
7 →}6
8 ←
32
16
8
4
2
1
5
4
3
2
1
Presuming it is best to allocate the largest number of hosts first, I have worked
through the areas by the highest number of hosts required. In our first subnet (MU
Building – Lower Zone) we require 120 hosts so must use 128 bit to represent our
subnet address as 64 is not enough. The first subnet however, is allocated to ‘routing’,
therefore we must start host IP addressing and as only one subnet for 120 hosts is
required we use 129+120=249, therefore 5 IP host addresses can be reserved for
expansion. Remember, we cannot use 0 or 256, and 255 is the subnet broadcast
address. This subnet is allocated the address 190.123.36.128/25, and is used to
represent all the three rooms MU023, MU029 and MU032. Therefore, the subnet has
the IP address range 190.123.37.129→190.123.37.254 - broadcast address being
190.123.37.255. Room MU023 would have incremented IP addresses from
190.123.37.129 → 190.123.37.169. Room MU029 would have incremented IP
addresses from 190.123.37.169 → 190.123.37.209 and finally room MU032 would
have incremented IP addresses from 190.123.37.209 → 190.123.37.249 (5 left for
expansion).
In our second subnet (Telford Zone) we require 80 hosts so use 128 bit again to
represent our subnet address. As the first subnet (190.123.36.128/25) has been
utilised, we must progress onto the next subnet. This is much like a speedometer
counter that turns one mile after the 9/10th, then turns the ten mile counter after 9
miles, etc. Therefore, this next subnet is 190.123.37.0/25 and allocates 40 machines in
each Lab01 and Lab02 at the Telford building - a total of 80 hosts.
The next subnet (190.123.37.128/25) is for the Staff Zone, which accommodates 70
hosts. Next, is the Upper Zone (190.123.38.0/25), comprising rooms MU011,
MU107, MU404, each having 20 hosts. The last subnet is for the Consultancy Rooms
1 and 2, which continues using address scheme 190.123.38.128/25 to allocate 20
hosts. Although we have an extra 105 IP addresses unallocated using this subnetting
scheme, continuity is controlled. All subnet addressing is displayed more clearly in
the chart that follows.
5
Chart Outlay of Subnetting and IP Address Configuration
IP Address Range
for Expansion
Broadcast
Address
Subnet Number
Lower
Zone
190.123.36.128/25 255.255.255.128 190.123.36.129→249 190.123.36.250→254 190.123.36.255
Telford
Zone
190.123.37.0/25
Staff
Zone
Subnet Mask
IP Address Range
Used on Hosts
Area
255.255.255.128
190.123.37.1→80
190.123.37.81→126
190.123.37.127
190.123.37.128/25 255.255.255.128 190.123.37.129→199 190.123.37.200→254 190.123.37.255
Upper
Zone
190.123.38.0/25
Consult
Zone
255.255.255.128
190.123.38.1→60
190.123.38.61→126
190.123.38.127
190.123.38.128/25 255.255.255.128 190.123.38.129→149 190.123.38.150→254 190.123.38.255
The chart not only shows each subnet address, but the broadcast address for each
subnet. Columns clearly show the allocation for IP addresses used on each host as
well as the range of spare IP addresses that can be used for future expansion.
3.2 Inventory and Installation
With relation to the Conclusive Physical Topology drawn previously, an inventory of
hardware requirements can be listed. However, with much research on devices quality
and pricing through http://www.hardware.com/, I alleged that using CISCO
compatible devices, cabling and connectivity would be best for quality, price and
reliability - also an extended warranty and contract for servicing is available.
Listed below are CISCO devices and cabling with given pictures and prices, but these
are only examples for illustration and price estimation.
Routers (4 Port Distributed)
Example Model : CISCO1721-VPN/K9-A (Cisco 1712 Modular Access Router)
Price: £1,095.00 (46% off List Price), Inc. VAT £1,287.00
Images and Prices courtesy of:
http://www.hardware.com/product.asp?id=CISCO1721-VPN/K9-A
The router detailed above ideally suits the Telford Router and the Wolverhampton
Secondary Routers, whereas a more expensive but obviously more powerful CISCO
router, should be implemented for the Wolverhampton Central Router, as it takes all
bottleneck traffic and utilises facilities with the Internet Service Provider. I have
included this also to illustrate price difference.
6
Example Model : C3745-VPN/K9 (CISCO manufactured Cisco 3745 VPN Security
Bundle)
Price: £6,380.00 (38% off List Price), Inc. VAT £7,497.00
Images/Prices courtesy of:
http://www.hardware.com/product.asp?id=C3745-VPN/K9
Switches
Example Model : WS-C2950-24 (24 port Cisco Switch)
Price: £360.00 (47% off List Price), Inc. VAT £423.00
Image/Prices courtesy of:
http://www.hardware.com/product.asp?id=WS-C2950-24
Example Model : WS-C29505X-48-SI (48 port Cisco Switch)
Price: £1,469.00 (46% off List Price), Inc. VAT £1,726.00
Images/Prices courtesy of:
http://www.hardware.com/product.asp?id=WS-C2950SX-48-SI
Patch Panels
Example Model : 24 Way Cat6 Value UTP Patch Panel (1U)
Price: £46.00, Inc. VAT £54.05
Images/Prices courtesy of:
http://www.comms-express.com/pd1132306824.htm?categoryId=20
7
Example Model : 48 Way Cat6 UTP Excel Patch Panel (2U)
Price: £85.00, Inc. VAT £99.88
Images/Prices courtesy of:
http://www.comms-express.com/pd-2099391648.htm?categoryId=20
Cabling
Example Model : CAB-5E-UTP-BLUE-20M
Price: £8.00, Inc. VAT £9.00
Example Model : CAB-6-UTP-GREY-10M
Price: £10.00, Inc. VAT £12.00
Images/Prices courtesy of:
http://www.hardware.com/search_category.asp?keyword=&category=FI2&current_pa
ge=1&start_page=1&family_id=&val0=&val1=&val2=&val3=&val4=&val5=&val6
=&val7=&lowPrice=&highPrice=&order_by=1
Connectivity
One of the most important factors to include in the network installation is a dedicated
communication line between the Wolverhampton Central Router and the Telford
Router (i.e. – a WAN link). This can be provided by an annual leased service from an
Internet Service Provider, who is responsible for servicing a dedicated line as well as
providing broadband internet accessibility. Due to the fact that this is a facility of
further education, I can presume that the best choice for an Internet Service Provider
is through British Telecom who, convey a hierarchy of dedicated services.
Exploring the British Telecom website for basic research into Private Circuits (leased
lines) from http://www.downloads.bt.com/b4b/pdf/Private_Circuit_pricing.pdf, I
discovered some information which could give some approximation for a reliable and
above moderate, powerful point-to-point connectivity. The MegaStream Ethernet and
BT Enterprise Ethernet service connects remote sites to a single, high speed
connection. The pricing structure required for the network solution detailed at this site
would involve a moderately high cost, but would include many services and support
such as corporate e-mail and internet access with the ‘plug and play’ adaptability to
the hardware prescribed. Security and maintenance support is also on-going.
8
A connection speed for the network proposed should be compatible with the speed of
routing technologies detailed. Therefore, a moderately high speed of 100Mbit/s would
be sufficient but incurs a flat connection charge and annual service charge along with
contract overheads. Although it is quite difficult to estimate a total cost, some
approximation for cost can be deduced from the website material.
New Site Connection Charge @ 100Mbit/s £6,250.00
Annual Site Rental
£14,000.00
The following table lists all devices for network inventory giving details, example
model numbers and associated prices.
Subnet
Zone Description
Number
Hardware
Description
Example Model
Price
Ports for
Expansion
None
Wolverhampton
Central Router
Router
C3745-VPN/K9
£7,497.00
All 4 used
None
Wolverhampton
Secondary Router
Router
CISCO1721VPN/K9-A
£1,287.00
All 4 used
Telford
Telford Router
Router
CISCO1721VPN/K9-A
£1,287.00
2 used, 2 more
available
Subnet 1
Lower Zone 1
Switch
WS-C29505X-48-SI
£1,726.00
8 Ports Spare
Subnet 1
Lower Zone 2
Switch
WS-C29505X-48-SI
£1,726.00
8 Ports Spare
Subnet 1
Lower Zone 3
Switch
WS-C29505X-48-SI
£1,726.00
8 Ports Spare
Subnet 2
Telford Zone 1
Switch
WS-C29505X-48-SI
£1,726.00
8 Ports Spare
Subnet 2
Telford Zone 2
Switch
WS-C29505X-48-SI
£1,726.00
8 Ports Spare
Subnet 3
Staff Zone 1
Switch
WS-C29505X-48-SI
£1,726.00
8 Ports Spare
Subnet 3
Staff Zone 2
Switch
WS-C29505X-48-SI
£1,726.00
18 Ports Spare
Subnet 4
Upper Zone 1
Switch
WS-C2950-24
£423.00
4 Ports Spare
Subnet 4
Upper Zone 2
Switch
WS-C2950-24
£423.00
4 Ports Spare
Subnet 4
Upper Zone 3
Switch
WS-C2950-24
£423.00
4 Ports Spare
Subnet 5
Consultancy
Room 1 and 2
Switch
WS-C2950-24
£423.00
4 Ports Spare
9
3.3 Costing and Flexibility
By defining the inventory and installation processes for the proposed network, costing
for the hardware configuration can be now estimated. The following table lists totals
with reference to the table prescribed in 3.2 Inventory and Installation.
Item
Quantity
Hardware Description
Example Model
Price
Total Price
1
CISCO 4 Port Central Router
C3745-VPN/K9
£7,497.00
£7,497.00
2
CISCO 4 Port Distributed Router
CISCO1721VPN/K9-A
£1,287.00
£2,574.00
7
48 Port CISCO Switch
WS-C29505X-48-SI
£1,726.00
£12,082.00
4
24 Port CISCO Switch
WS-C2950-24
£423.00
£1,692.00
7
CISCO 48 Port Patch Panel
48 Way Cat6 UTP
Excel (2U)
£99.88
£699.16
4
CISCO 24 Port Patch Panel
24 Way Cat6 Value
UTP Patch Panel (1U)
£54.05
£216.20
5000m
UTP Type 6 Ethernet Cabling
CAB-6-UTP-GREY10M
£12.00
£6,000.00
5
Labour/Installation
40 hrs (1week)
£12.00 / hour
£2,400.00
1
ISP WAN Integration
BT Ethernet Private
Circuit
£20,250.00
£20,250.00
1
Maintenance/Overheads
Ducting, Electrics,
Insulation, etc.
£3,000.00
£3,000.00
Total derived for Inventory and Network Installation
£56,410.36
Although we can produce a figure by using the tables created above, it must be
recognised that other overheads and cost may need to be taken into consideration.
These are reflected on more in the next section - 4. Conclusion. Flexibility of this
network reflects on expansion and possible re-developments or introduction of future
technologies. By reviewing the table in 3.2 Inventory and Installation, we can
conclude that;
•
•
•
•
•
In the Lower Zone - although 24 switch ports could give an additional 24
hosts, the subnet only allows 5 more IP addresses within that subnet range
In the Telford Zone – all 16 additional switch ports can be used but some 30
subnet IP addresses cannot be utilised
In the Staff Zone – a total of 26 switch ports are available for expansion, but
28 subnet IP addresses cannot be utilised
In the Upper Zone – 12 switch ports are available for expansion, but 54
subnet IP addresses cannot be utilised
In the Consultancy Zone – only 4 switch ports are available for expansion,
leaving 101 subnet IP addresses not utilised
10
4 Conclusion
Throughout the construction of my proposed networking solution, along with the
allocation of subnets and configuration of hardware, I have listed a few points for
conclusion, bulleted below.
•
•
•
•
•
•
•
Although already incorporated in my solution, a more powerful and reliable
router should be implemented as the Wolverhampton Central Router as this
takes all ‘bottle-neck’ traffic
The Telford Router can be expanded to introduce a wireless access point and
implement wireless accessibility for laptops around that campus
The Consultancy Zone is allocated within the ‘student zone’ for security and
as consultancy staff are not officially allocated to the university, they share no
priority over students or retain official staff privileges
Expansion is some subnets may already be restricted if a certain number of
other devices, such as printers, are required in separate rooms
Threading cable through many floors in the instance of the Upper Zone may
require extensive work and future expansion to other floors may require
consideration
Cabling to different rooms may extend the boundaries originally proposed for
each subnet. For example, although we have used only one switch in the
Consultancy Zone, it provides cabling to two physically close, but separate
rooms
Originally, it was considered that the Staff Zone should utilise an 80-Port
switch, but by using two 48-Port switches not only works out cheaper, but
leaves an extra 4 IP addresses to be configured in future expansion.
5 Notes
In addition to my conclusion points it must be noted that I have over estimated on
installation costs in several ways (e.g. using Cat 6 cabling as opposed to Cat 5e, and
by over-estimating on the cabling quantity). However, it must be remembered that in
situations of installation and network continuity testing, a lot more time and so money
may have to be incorporated. A lot of expenditure may be dependant on installation
time and reliability of hardware components.
11
6 Reference A : Internet Research Listings
The following links are internet websites, of which I researched to enhance my
understanding of sub-netting, network masks, CIDR, along with collecting other
technical information and prices.
www.cisco.com, Cisco - IP Addressing and Subnetting for New Users:
(Modified : 26 September 2005 18:54:41) [online]. Cisco Systems, Inc.
170 West Tasman Dr. San Jose, CA 95134, USA [cited 23rd April 2006].
<http://www.cisco.com/warp/public/701/3.html>
computer.howstuffworks.com, (Modified: 14 May 2006 08:20:31) How LAN
Switches Work [online]. HowStuffWorks.com c/o Convex Group, Inc.
One Capital City Plaza, 3350 Peachtree Road, Suite 1500, Atlanta, GA 30326
[Cited 30th April 2006].
<http://computer.howstuffworks.com/lan-switch17.htm>
University of Wolverhampton, School of Computing & Information Technology
(Modified : 14 May 2006 20:35:40), WOLF Topic : CP2023 Computer Networks WOLF Topic Banner : CP2023 Computer Networks [online].Wolverhampton:
University of Wolverhampton [cited 28th April 2006].
<http://wolf-nt.wlv.ac.uk/common/newframeset.asp?modid=wlv0305>
www.ralphb.net, (Modified: 14 May 2006 20:29:56) Subnetting [online].
Ralph Becker [cited 14th April 2006].
<http://www.ralphb.net/IPSubnet/subnet.html>
www.hardware.com, (Modified : 14 May 2006 20:41:04) Hardware.com new&refurbished 3Com, Alcatel, Cisco, D-Link, Dell, Emulex, Epicenter, Extreme,
Foundry, HP, IBM, Linksys, MGE, NetGear, Nortel, Polycom, PowerDsine,
Prolabs, Sun, Usystems plus approved&compatible GBICs, memory, cables and
accessories: [online]. Hardware.com, Trafalgar House, Kemble Enterprise Park,
Cirencester, Gloucestershire, GL7 6BQ, United Kingdom [cited 12th May 2006].
<http://www.hardware.com>
www.comms-express.com, Cat6 Patch Panels :( Modified: 28 April 2006 10:46:43)
[online]. Comms Express Limited, Unit 7 Grafton Place, Dukes Park Industrial Estate,
Chelmsford, Essex CM2 6TG [cited 9th May 2006].
<http://www.comms-express.com/pd-2099391648.htm?categoryId=20>
www.bt.com, (Modified: 15 May 2006 22:37:36) BT.com Products & Services
[online]. BT Group plc, BT Centre, 81 Newgate Street, London EC1A 7AJ
[cited 15th May 2006].
<http://www.bt.com/store/home.jsp?UserSegment=SME>
12
7 Reference B : Published Research Material
The following references list published material, of which I used for further reading
into related topics.
SYBEX INC. (2002) NETWORKING COMPLETE (Third Edition),
Sybex Inc., 1151 Marina Village Parkway, Alameda, CA 94501, 2002
ISBN: 0-7821-4143-9
PARKINSON, GEORGE (2001) NETWORKING PRINCIPLES,
Computeach International Limited, University House, PO Box 51, Dudley, West
Midlands DY32AG.
ISBN:
13