The telephony system for the gallery can be VoIP, direct telephone and broadband access together with PABX with configurations as per below table.
VoIP
Direct Telephone + Broadband Access
PABX
VoIP switch x 1
VoIP gateway x 1
Telephone lines x 3
Computer terminals x 1
VoIP telephones x 20
Telephones x 20
Telephone lines x 20
Broadband modem
Cabling
switch
PABX telephone x 20
PABX system x 1
Telephone line x 3
Broadband modem
Cabling
switch
b) Features of above three options are as follows:
Option 1: VoIP
VoIP refers to voice over internet protocol. Voice stream is digitized, encoded, packetized, compressed and transmitted to the final destination via the internet using IP. At the receiving end, these IP packets are decompressed, decoded and digitized to re-produce original voice stream. As voice is compressed and sent through the internet, up to eight times the number of calls can be made on the same line without affecting the quality of the sound. Hence, it can reduce largely the tolls charged by public telephone company especially when the company makes long distance calls. The hardware requirements for VoIP are not so much. It requires mainly a PC, an efficient network and internet connection. Therefore, the cost of operating the system is low. Many VoIP service providers nowadays can provide many modern telephone features for VoIP such as voice mail, display caller ID, last number redial, call blocking, conference call, call waiting, call forward, etc. Apart from voice, data, fax and other multimedia can also be sent or received via the internet. This leads to more efficient use of the broadband service which is usually a fixed charge to the company. It is also very flexible to allow different voice communication channels like PC-to-Phone and PC-to-PC. However, as VoIP depends on the internet for voice transmission, if the internet connection goes down, the company's telephone system will go down as well. Also, hardware for VoIP e.g. PC, modem all requires electric power supply. The telephone system will be affected in the event of a power interruption. As internet is the backbone for VoIP, VoIP also encounters the problem of security issues including identity and service theft, viruses and malware, denial of service, spamming, call tampering and phishing attacks. The quality of service also largely depends on the efficiency of the company's broadband connection and the hardware.
Option 2: PABX
PABX refers to private automatic branch exchange. It makes connections among internal telephones within an organization by using a circuit switch. Also, it allows the organization to connect public telephone network and internet via truck lines and modem. Each telephone set is assigned its own extension number for making internal and external calls. PABX reduces largely the cost for internal calls because only a few telephone lines are required for making external calls and internet access. By using circuit switching network, users of PABX can be very flexible to establish internal and external calls, maintain and disconnect connections as per their own requirements. They can transfer external call to another extension, make internal call whilst connecting to external call and collect calls information for accounting purpose such as metering calls. Other advanced calling features like auto attendant, auto dialing, call barring, call parking, call forward, call waiting, call hold, conference call, hunt groups, pick-up groups, call diversion, voice mail and welcome message can also be available under PABX telephone system.
Option 3: direct line (telephone function provided by telephone service provider)
Direct line refers to the connection of telephones within an organization to a public telephone service network by leasing of the external telephone lines provided by the public telephone service provider. Each telephone requires the connection to an external line for making internal and external calls. Only two persons can speak at the same time on each telephone line. Individual telephone number is assigned for each telephone line for identity and for billing purpose. Billing is based on a time usage basis for each telephone line. Hence, the charge for local and international calls is relatively higher than other options like VoIP and PABX. However, as public telephone network is being used, the quality is more reliable than circuit-switched public telephone network. Each direct line has direct relationship with the physical location of the network user. Therefore, it is very easy to locate the physical location of the network user when emergency call is made. As each telephone set is connected to the telephone company phone line, it can provide direct current to power independent of local power supply. Direct line is more secure than other internet connected telephone devices e.g. VoIP which is vulnerable to the attack by hackers. Nowadays, many public telephone companies can provide advanced telephone features for direct lines like call waiting, call hold, voice mail, call forward, last number redial, etc. With the connection of a broadband modem, users can also gain access to the internet.
c) Cost of equipment and installation
PABX
Direct Line
VoIP
One-time setup cost
Cabling:
HK$12,000
Equipment:
HK$75,200
Cabling:
HK$8,000
Equipment:
HK$6,200
Cabling:
HK$20,000
Equipment:
HK$26,200
d) Cost of operating the system
PABX
Direct Line
VoIP
Operation cost per year
External line leasing cost:
HK$7,200
Hardware maintenance:
HK$15,000
Operator:
HK$120,000
External line leasing cost:
HK$48,000
Hardware maintenance:
HK$2,500
Operator:
HK$120,000
External line leasing cost:
HK$7,200
Hardware maintenance:
HK$8,000
Operator:
HK$120,000
e) Recommendation
Assumption: Working in 10 years
PABX
Direct Line
VoIP
Total cost in 10 years
One time cost:
HK$87,200
Operating cost x 10 years:
HK$1,422,000
TOTAL COST:
HK$1,509,200
One time cost:
HK$14,200
Operating cost x 10 years:
HK$1,705,000
TOTAL COST:
HK$1,719,200
One time cost:
HK$46,200
Operating cost x 10 years:
HK$1,352,000
TOTAL COST:
HK$1,398,200
PABX
Direct Line
VoIP
Total cost in 10 years
2
1
3
Features
1
3
2
Scalability
3
1
2
Share with Data network
2
1
3
Ease of implement
1
3
2
Security
2
3
1
TOTAL SCORE
11
12
13
Referring to above table, if we give a score from 1 to 3 with 3 the highest score to each criterion, VoIP gets the highest total score of 13. Hence, I recommend the use of VoIP telephone system for the gallery.
Task 2
According to the question, "A staff computer network is required for email, standard office software, Internet access and for gallery database that record full details of all exhibits". Hence, the internet services required includes: http, ftp, SMTP, real-time broadcasting.
Streaming - for video
File sharing (ftp) - for uploading and downloading design, video, graphic files
Web sharing (http) - for demonstrate web site prototype
Secure web sharing (https) - SSL services for secure web content transmission
Mail service (SMTP and POP3) - for mail transfer between clients and company
Proxy server - for security and internet transfer caching
You can imagine that the gallery needs to upload and download a large amount of voice, pictures and multi-media files, and hence it is recommended the bandwidth should be 100 Mbps.
In a recent estimation, assuming that there are totally 1000 email received and sent per day and the average size for each email is 500K bytes. Also, there are 2000 pages of 2 Mbps each for HTTP traffic and 80 Mbps for video streaming per day.
Email traffic: 1000 email per day x 500K bytes size per email
Total email traffic size is 488.28 Mbps per day.
HTTP traffic: 2000 page x 2M size per page
Total HTTP traffic is 4,000 Mbps.
Video streaming: 80M per day
Total traffic size per day = 488.28M + 4,000M + 80M = 4,568.28 Mbps
c)
PCCW (www.pccw.com.hk)
Communilink.net (http://www.communilink.net/)
HGC (www.hgc.com.hk)
d) Compare the features and price provided by different service providers.
PCCW
HGC
Communilink
Features
broadband, wi-fi
Broadband service
Business server
Price
setup cost
operation cost per month
nil
HK$298
nil
HK$388
nil
HK$1,950
Support hours
24
24
24
PCCW Can provide the required services while having the lowest setup and operation cost. Hence, I recommend PCCW to be the ISP provider for the gallery.
Task 3
Information workstation
Setup an application which demonstrates the information by accessing to the database shared in the intranet of the Gallery. The visitor can access information on every exhibit including the year, name, content and background information of the exhibit together with details of the artists via the workstation but they do not have right to modify and update any information to the gallery database. Staff can update the data via the database of intranet. In case there is any problem in the workstation, it only affects particular workstation instead of the whole system. The application limits the access right of visitor, simplified the support by simple reboot of the workstation.
Intranet website
Alternatively, an information system is designed for each gallery exhibit and the information is updated to each individual workstation. Visitors can access information of each exhibit via this information system through the workstation.
Setup a website in the intranet of the Gallery, web server will access the database directly and will provide the HTML as dynamic web page to display the information to the visitor. Security of the web of the web server will be concerned. It is because it increases the risk for the exposure to viruses and malware, denial of service attack by opening the network access to public.
You can write an Apps which is downloadable via App Store, and access the database via intranet wifi network.
b)
Standalone
Client-server
Mobile
Advantages
Faster access to information
High security and removal of the risks from viruses, malwares and denial of service attack
Easy to operate
Real-time synchronization of data
Save the workload for data update
Provide up to date information to the visitors
Can synchronize data in real-time with WiFi
Allow more visitors to gain access the exhibit information
Disadvantages
Cannot synchronize data in real-time
increases the risk for viruses and malware, denial of service attack by opening the network access to public
Need to update the Apps via Wifi network
c)
Standalone
Client-server
Mobile
Setup Cost
Licensing cost:
nil
Equipment Cost:
HK$10,000
Licensing cost:
HK$2,000
Equipment Cost:
HK$11,000
Licensing cost:
HK$1,000
Equipment Cost:
Nil
Operating Cost Per Year
Network cost:
nil
Maintenance cost:
HK$10,000
Network cost:
HK$18,000
Maintenance cost:
HK$120,000
Network cost:
nil
Maintenance cost:
HK$12,000
d) Rewrite of content using another languages as information.
Another option can be translate the content using dynamic translation tools, such as SysTrans, or Google Apps.
e) Recommendation
Assumption: Working in 10 years
Standalone
Client-server
Mobile
Total cost in 10 years
One time cost:
HK$10,000
Operating cost x 10 years:
HK$100,000
TOTAL COST:
HK$110,000
One time cost:
HK$13,000
Operating cost x 10 years:
HK$1,380,000
TOTAL COST:
HK$1,393,000
One time cost:
HK$1,000
Operating cost x 10 years:
HK$120,000
TOTAL COST:
HK$121,000
Total cost in 10 years
3
1
2
Features
1
2
3
Security
3
2
1
TOTAL SCORE
7
5
6
Referring to above table, if we give a score from 1 to 3 with 3 the highest score to each criterion, standalone gets the highest total score of 7. Hence, I recommend the use of standalone workstation for the gallery.
Task 4
Network Topologies - Star
Star - equipment: Router, Switches, Firewall
Media - copper wire
Bus Topologies
Equipment: Wireless Router, Access Points
Media: radio wave
Ring Topology
FDDI network
Media: optical fibre
Recommendations
Star
Bus
Ring
Media
Copper
Radio
Optical Fibre
Speed
10/100/1000 Mbps full utilized by a single staff
< 54Mbps divided by 15 staff
>1000Mbps
Cost of implementation
Cabling charge around $3000 ($200 per socket)
No cabling charge
WiFi card/interfaces ($150 per PC)
Cabling charge
Around $6000
Optical interface
($1200 per PC)
Security
High (dedicate channel)
Low (shared channel)
High (dedicate channel)
Sharing Bandwidth
No
Yes
No
Recommendation
Assumption: Working in 10 years
Star
Bus
Ring
Cost of implementation
3
2
1
Speed
2
1
3
Security
3
1
2
TOTAL SCORE
8
4
6
Referring to above table, if we give a score from 1 to 3 with 3 the highest score to each criterion, star topology gets the highest total score of 8. Hence, I recommend the use of star topology for the gallery.
The single site of 15 staff, although WiFi seems cheaper in implementation, however, after considering the security and speed of communication, it is better to implement copper cabling. Optical Fibre seems unnecessary and the cost of implementation is too high.
Conclusion
In conclusion, to meet the gallery's requirements for a telephone system for its staff, there are basically 3 options namely VoIP, PABX and direct telephone with broadband access. Although direct telephone with broadband access is more secure and easy to implement, the operating cost is relative high. The setup cost for PABX is very high. Hence, I recommend the use of VoIP which is cost effective, flexible and ease to implement. In consideration of large traffic size of the gallery, 100Mbps broadband access is required. As PCCW can provide such service with relatively lower cost, I recommend PCCW to be the ISP provider for the gallery. For the visitor information system, although mobile and client server can provide real time information, the cost of operation and maintenance is high and may involve security issues like viruses and denial of service attack. Hence, I recommend the use of standalone workstation. Star topology with copper cabling seems to be the best option for staff computer network of the gallery in consideration of its cost, security and speed of communication. Optical Fibre seems unnecessary and the cost of implementation is too high.
