Members List of ISP

Members List of ISPAB (in Alphabetical order)

Aamra Networks Limited.
Sharful Alam
Cheif Operating Officer
Faruq Rupayan Tower (20th Floor)
32, Kemal Ataturk Avenue
Banani, C/A, Dhaka-1213
E-mail- sharful.alam@aamra.com.bd
Cell- 01713000258
Phone- 8861100
Fax- 8860077

Access Telecom (BD) Ltd.
Zain Omar
Suite-901, Concord Tower
113, Kazi Nazrul Islam Avenue, Dhaka
Phone: 9335607-10
Email: zainomar@accesstel.net

Advanced Data Networks System Ltd.
Red Crescent Concord Tower (19th Floor)
17, Mohakhali Commercial Area
Dhaka - 1212, Bangladesh.
Phone: +(880 2) 886 1234 - 8
Fax: +(880 2) 988 7551
Website: http://www.adnsl.net
Email: info@adnsl.net

Aftab IT Ltd.
Akhtaruzzaman Manju
Eastern Trade Center (14th floor)
56 Inner circular Road, Dhaka
Phone: 9352356, 0171527523
Email: manju@aitlbd.net

Agni Systems Ltd
Md. A. Salam
Navana Tower, (11th floor)
Suite-A, 45, Gulshan-1, Dhaka-
Phone: 8812379
Email: info@agni.com

Akceycom Limited
Dinesh Dissanayake
Uday Tower (9th Floor)
Plot#57 & 57/A
Gulshan -1, Dhaka-1212
Phone- 88 02 9861681
Fax- 88 02 9862159
E-mail- info@aknetbd.com

Akij Online Ltd
SK. Aminuddin
Akij Chamber, 73-Dilkusha, Dhaka
Phone: 9571278-80
Email: info@akijonline.com

Always On Network Bangladesh Ltd
Ameer Ali
Chief Coordinating Officer
House- CWN CB) -6, Road – 36,
Gulshan -2, Dhaka-1212
Phone: 8850643-4, 01611410323
Email: ispab@aonbd.net

Asia Pacific Communication
Sk. Abdur Rahim
Keari Plaza (4th floor)
83, Satmasjid Road,Dhanmondi 8/A
Dhaka-1209
Phone-9666314, 0173005899
Email-skrahim@apcbd.com

Bangladesh Internet Exchange Ltd
Rafel Kabir
House-26, Road-328, Block-K
Banani, Dhaka-1213.
Phone: 9893308-9
Email: info@bdnet.com.bd

Bangladesh Online Ltd.
Ershad Shafi Chowdhury
House 19, Road 35, Gulshan
Dhaka 1212
Phone: 8815559, 0171538734
Email: iru@bol-online.com

BDCOM Online Ltd.
Sumon Ahmed Shabir
House # 43, Road # 27(Old) 16 (New)
Dhanmondi R/A, Dhaka 1209
Phone: 8125074-5,8113792,8124699
Fax: 880-2-8122789
Email: office@bdcom.com

Bijoy Online Ltd.
Nawshad Ahmed
Bijoy Online Ltd.
Nawshad Ahmed
Basati Dream, Suit # A1
House No # 03, Road No # 20,
Gulshan – 1, Dhaka – 1212
Dhaka-1212.
Phone: 8820301-5, 0187040808
Fax : 88-02-8818299
Email: nawshad@bijoy.net

BRACNet Limited
Maj Gan Syeed Ahmed BP, awc, psc (retd.)
Chief Executive Officer
House 26, Road 28, Block K
Banani, Dhaka 1213
Phone: 9893333, Fax: 9884587
E-Mail: syeed.ahmed@bracmail.net, munirul.hoque@bracmail.net

Broadband Telecom Services Ltd.
Mahbubul Enam
General Manager
Ispahani Building (5th floor)
Agrabad C/A, Chittagong-4100
Phone: +88 031-2520550/6, 714126
Email: info@bbts.net

BTS Communications (BD) Ltd.
Abdul Kader
Swapnil-4, Mirzazangal
Sylhet - 3100, Bangladesh
Phone: 9860044, 821-715395, 0189257998
Email: bts@btsnet.net

CITech CyberNet Ltd
Subrata Sarker Shuvra
Aziz Bhaban (6th floor), 93,
Motijheel C/A, Dhaka-1000.
Tel- 7170990-1
Email-shuvra@citech.net

CGS Communication
Sayyedul Hoq
House -43, Road – 4/A
Dhanmondi, Dhaka
Phone- 8622485
E-mail- toufiq@cgscomm.net

Chittagong Online Limited
Engr. Tahmid Anwar
Managing Director
Arup Bhaban(2nd floor),
107, Agrabad C/A, Chittagong-4000
Phone: 031- 714447, 01713113113
Email: ceo@colbd.com

Communication One (pvt) ltd
Mohammad A.M.Muyeed
Erectors House,(12th floor)
18, kamal Ataturk Avenue
Banani, C/A, Dhaka-1213
Phone- 8861886

Connect BD Ltd.
Khandoker A. Al. Azad
House-42, Road-1/A, Block-1
Banani, Dhaka
Phone: 8816491-2, 0191328003
Email: azad@connectbd.com

CPM Blue Online Ltd
Khalequzzaman
Road-12/A, House-79, (4th floor),
Dhanmondi,R/A, Dhaka-1209.
Phone: 8154352, 8112458
Fax: 8753290
Email: s.sharif@cpm-bd.com

Cyberx IT Ltd.
S.M. Golam Faruk Alamgir
586/C, Khilgaon, R/A,(Ground Floor),
Dhaka
Phone: 7211616, 7212266
Email: arman@cyberxbd.com

Daffodil Online Ltd
S.M. Altaf Hossain
102, Shukrabad, Mirpur Road
Dhanmondi, Dhaka
Phone: 9143258-60, 0189212555
Email: ceo@daffodilnet.com

Data Edge Ltd
Mr.Md. Asifuzzaman
Sadharan Bima Bhaban-2
13th floor, 139, Motijheel, C/A
Dhaka-1000
Phone-7170368-70
E-Mail: asif@data-edge.com

Data Net Corporation Ltd.
Shaiful Alam
19/2, West Panthapath, Dhaka
Phone: 9113232
Email: litu@1postbox.com

Dekko Airnet Ltd.
Faisal Asif Rahman
T.K. Bhaban (17th Floor)
13, Kawran Bazar, Dhaka-1215.
Phone No : 9110268, 9112492
Fax : +880-2-8123608
E-mail : info@dekko.net.bd

Desh Online Services
Pronab Chatterjee
83/4, Kadamtala, East Bashaboo,
Dhaka-1214
Phone-7205304, 0189297853
Email: pronab@deshonline.net

Dhaka Com Ltd.
M.A. Hakim
Navana Tower (7th floor)
45 Gulshan South C/A Circle – 1, Dhaka
Phone: 8819220
Email: admindiv@dhakacom.com

Dominox Technologies Ltd
Anirban Bera
House-1/A, (5th floor), Road-23
Gulshan –1, Dhaka-1212.
Phone: 9894763-9894737
Email: anirban.bera@dominox.com

Drik ICT Ltd
S M Altaf Hossain
Managing Director & CEO
House- 58, Road-15/A
Dhanmondi Dhaka 1209
Phone: 9103222, Fax: 02-9110299
Cell: 01819 212 555
Email: ispab@drikict.net

Drishte Online Ltd
S. I.M. Alimgir
E-4, Monico Mina Tower
48/3, West Agargoan
Sher-e-Bangla Nagar
Dhaka-1207
E-mail- alamgir@smile.com.bd
Phone- 8115394

Druti Network Ltd
Dr. Md. Asaduzzaman Khan
House-28, Shahjalal Avenue,
Sector-04, Uttara, dhaka-1230
Tel- 8919173,8963963
Email-dr.asad@druti.net

Eastern Link BD (pvt) Ltd
Sujit Roy
48/3, Monico Mina Tower
West Agargoan
Sher-e-Bangla Nagar
Dhaka-1207
Phone- 8118708
E-mail-admin@smile.com.bd

Ektoo Limited
Pervez Sajjad
House:3, Road:7
Block:F, Banani
Dhaka 1213
Phone- +880-2-988-9175, 885-8131
www.ektoo.net.bd

Fusion Net
Nackshab Omar Rabbani Uthant
Managing Director
Navana Tower (22nd floor),
45, Gulshan Circle-1, Dhaka-1212
Phone: 8857502, 01711521512
Email: uthant@fusionbd.net

Geotel IT Ltd
Md. Majibul Hoque
69/1, Purana Paltan Line
Dhaka-1000.
Tel-8357325
Email-majib@xpeedgroup.com

Global Access Ltd.
Mr. Humayun Kabir
Grameen IT Park, Grameen Bank Bhaban
Mirpur-2, Dhaka-1216
Phone: 8011597, 9013363
Email: humayun@golbd.net

Global Information Network Ltd.
Ali Ashraf
Southland Center (5th Floor)
05- Agrabad, C/A, Chittagong
Phone- 031-726315-7
E-mail: ashraf@globalctg.net

Global Link Telecom Ltd
Abdullah A. Mamun
91, New Eskaton Road, Dhaka
Phone: 9332000
Email: amamun@glinktel.com

Grameen Cyber Net Ltd.
Azhar H. Chowdhury
RM Center 4th Floor
101 Gulshan Avenue
Dhaka-1212
Phone: 8812103, 8857809, 9886301-2
Email: azhar@citechco.net

HRC Technologies Ltd
Minhaz Uddin Foyez
26- Shyamoli,
Bir Uttam A.W.Chowdhury Road,
Dhaka-1207
Phone: 9131267
E-mail:minhaz.foyez@hrctech.net

Ichinet Ltd.
Dipak Bhattacharjee
10-HSS Road, Chittagong
Phone: 031-624932
Email: dipak@banol.net

IDEA Technologies.
Syed Osama Jalal
12/1, Salimullah Road
Mohammedpur, Dhaka-1207
Phone - 8159381, 01713043747
E-mail-osama@ideabd.net

IDS Bangladesh.
Barkatul Alam
Iqbal Centre, (5th floor)
42, Kamal Ataturk Avenue,
Banani, Dhaka- 1213
Phone- 8819449, 01713000554
Email: info@idsbangladesh.net

Information Services Network Ltd.
Mr. Habibul Alam ( Bir Protik)
TMC Building
52, New Eskaton Road, (4th floor)
Phone: 8322785-8
E-Mail: halam.isn@bangla.net

Innovative Online Limited
Mr.Shahriar Kabir
Jibon Bima Bhaban, 5th floor,
56, Agrabad, C/A, Chittagong-4100
Phone: 031-816778, 01911310473
Email: shahriar@iolbd.net

Insoft Systems Ltd.
Shoeb Chowdhury
Ahamed Tower (5th floor)
H#54/1, R@4/A, Dhanmondi
Phone: 8629027
Email: insoft@neksus.com

Intech Online ltd
Jami Mohammad Khan
3/1-H, Purana Paltan Dhaka-1000.
Phone: 9553886, 9553715
Email: jami@intechworld.net

International Computer Connections
Saiful Islam Siddique
BSRS Bhaban (4th floor),
12, Kawran Bazar, Dhaka-1215.
Phone: 9111514, 9110908
F ax : 8129734
Email: saiful@icc.com.bd

Is Pros Limited
Shah M Reaz
41/1, Kazi nazrul Islam Avenue
Zeenat Bhaban(5th floor)
Dhaka-1215
Phone- 8126957
E-mail – hasaan@isprosltd.com

Libra Computer Aid.
Javed Bukth
House-99, Road 11/A, Dhanmondi
Phone: 8112881, 8112908
Email: libra@bangla.net

Link3 Technologies Ltd.
F. M. Rashed Amin
Bulu Ocean Tower (16th Floor)
40 Kemal Attaturk Avenue, Banani.
Phone: 9892022, 8852219, 8854620
Fax : 9888642
Email: biddut@link3.net

Maisha Technologies Ltd
Mufti Mohammed Zahid
House-17, Road-3, Block-B
Bansree, Rampura, Dhaka.
Phone: 7286790, 7287600
Email: info@mtlbd.net

MB Telecom
Subrata Bardhan
13- Kawran Bazar
T.K. Bhaban (18th floor)
Dhaka-1215
Phone- 8150210-11
E-mail- subrata@inetbd.com

Metronet Bangladesh Ltd.
Syed Almas Kabir
12-Sonargaon Road 18th fl
Sonartori Tower, Dhaka-1000.
Phone: 9671381
Email: info@metrobd.net

Mirae Company Limited
Chang Hun Jang
North Tower, 8th Floor
107 Dhaka-Mymensing Road,
Sector-7, Uttara Model Town
Phone- 8954091, 8917873, 9891591
E-mail- sumon@miraebd.net

MLB Net
M. A. Juber Ahmed Khan
885-Old Hospital Road
Moulavibazar.
Phone: 0861-61378
Email: jbar@mlbd.net

M.R.Khan Joint International Trade Center
Moshiur Rahman Khan
Managing Director
New Town, Main Road, Madaripur.
Phone: 01711003507
Email: info@kolbd.net

Net Access Bangladesh
Mohammad Wasiuddin Rajesh
Meherba Plaza (9th floor)
33, Topkhana Road, Dhaka.
Phone: 9567405,9559233,9550654
Mobile: 0173004561
email: rajesh@sayboltgroup.com

New Generation Graphics Limited
Khadem Mahmud Yusuf
Safura Tower (13th floor)
20, Kamal Ataturk Avenue,
Banani, Dhaka.
Phone: 8856203, 8859365

Nextgen Networks Limited
Sefat-E-Sultana
Managing Director
1/2, Monipuripara, Tejgaon, Dhaka.
Phone: 9138726, 01678036602
Email: kmnalam@nextgen.net.bd

Nreach – net (pvt)ltd
Abdul Musabbir Ahmed
Nitol Center
71, Mohakhali, C/A
Dhaka-1212
Phone- 8833031
E-mail- arup@nreach.net.bd

Optimax Communication Ltd
Emdadul Huq
House: 90, Road: 23, Block: A
Banani, Dhaka-1213
Phone: 8853356,8853753
Email: emdad@optimaxbd.net

Poly IT Ltd
Md. Sanwar Hossain
52/2, Toyenbee Circular Road
Motijheel, Dhaka
Phone: 7125925
Email: sanwar75@hotmail.com

Pradeshta Ltd.
Samudra E Haque
House-24, Road-13/C, Block-E, Banani, Dhaka
Phone: 9882751, 9884674
Email: haqe@prodeshta.com

Proshika Computer Systems
Qazi Rubayet Ahmed
Proshika Bhaban, Section-2, Mirpur, Dhaka
Phone: 8012717
Email: rubayet@bdonline.com

Radiant Communications Ltd
Muhammed Nura Alam Bhuiyan
Managing Director
Suite A 3-4 & D 3-4, House-15, Road-17,
Kemal Ataturk Avenue, Banani, Dhaka -1213
Phone: 8834229, 01713227766
Email: shaibal@radiantbd.com

Ranks ITT Ltd
Mr. Iqbal Chowdhury
Redcrescent Borak Tower (Level 10)
37/3/A,Eskaton Garden Road,
71-72,Old Elephant Road,Eskaton
Dhaka-1000
Phone: 8361381
E-mail: info@ranksitt.net

Reve Systems
Rezaul Hassan
308-C, Mailbag Chowdhury Para
Dhaka-1219.
Phone: 7217330
Email: info@revesoft.com

Royal Green Online Ltd
33- Kawran Bazar (2nd Floor)
Dhaka-1215
Phone- 8142760-1, 8143347
E-mail- royalgreen.admin@gmail.com

Sirius Broadband (BD) Ltd
Mansur Habib
Awal Cene (17th floor)
34, Kamal Ataturk Avenue
Banani C/A, Dhaka
Phone: 9891843
Email: mansur@siriusbb.com

Software Shop Limited
Mahabub Morshed
27-28 Main Road Block-Kha
Section – 6, Mirpur, Dhaka
Phone: 8019179, 9116496
Email: cgl@concorde.bangla.net

Sorob IT Ltd.
Mohammed Billal Hossain
Kohinoor Tower-1, House- 7 (5th floor, E-1)
Road – 7, Gulshan-1, Dhaka-1212
Phone - 9895167, 01713033014
E-mail-billal@sorobit.com

Spark Systems Ltd
Salim Mohammod
House-43, Road-04, Sector-03
Uttara Model Town
Dhaka-1230
Phone- 8918091, 8919344
E-mail- info@sparkbd.net

Spectra Net Ltd 0020.
Faisal Jalil Chowdhury
Specatra Net Ltd, Sattar Chamber
99 Agrabad C/A, Chittagong
Phone: 031-710405-7
Email: fjasc@spnetctg.com

Square InformatiX Limited
Ahmed Ullah Bhuyian.
Square Centre, 48, Mohakhali C/A
Dhaka-1212.
Phone: 8817729-38, 011849899
E-mail: ahmed@squaregroup.com

Techno Online Ltd
Rubiyat Hossain
House-256, Road-6, CDA, Agrabad,
Chittagong-4100
Phone: 031-813133, 813704
Email: rubiyat@techno-bd.net

Telnet Communication Limited
Saiful Arefin Khaled
Director
House -04, Road -27,
Dhanmondi, Dhaka-1209
Phone : 8113999 , 8113333
Email : ispab@telnet.com.bd

Texas Electronics Ltd.
Kaiser Huda
Safura Tower (9th flr),
20 Kamal Ataturk Avenue Banani, Dhaka
Phone: 8861111
Email: info.tel@texasgroup.net

Westec Ltd.
Rabiul Hossain
H.H. Building (4th Floor)
52/1, New Eskaton
Dhaka.
Phone: 9352824
Email: info@bdlink.com

X-Net Limited
S. Shapir Khasr
1103, Concord Tower
113, Kazi Nazrul Islam Avenue
Dhaka-1000
Phoae- 8321051
E-mail – info@x-netbd.com

In Windows XP
1. Click Start->All Programs->Accessories->Command Prompt.
2. Click Command Prompt This will open a DOS command window.
3. Type: notepad C:/Windows/System32/drivers/etc/hosts
4. Locate the line 127.0.0.1 localhost
5. To block the website google.com for example, just add this text under 127.0.0.1 localhost:

127.0.0.1 google.com
127.0.0.1 www.google.com
You can add as many sites any site, However you will need to prefix it with "127.0.0.1".

6. Save the file
Google will now be blocked in all web browser. This is an advanced but easy method on how to blow a website.

How to block a website

For Business

Windows 7, Vista, 2003, XP

For Home

Windows 7, Vista, 2003, XP

There are many reasons why people ask how to block a website. Some of the most common reasons are to prevent children from having access to certain site content such as adult and gambling. For employers, blocking websites is the way to increase employees' productivity. So we want to show you how to block a specific website and avoid problems connected with it.
The hosts file method and blocking website by using Internet Explorer are free but can be easily bypassed. Another way is to use special software such as Employee Monitor (for Business) or HT Parental Controls (for Home), which lets you block website more effective and has many advantages.

How to block a website using the Hosts file

The location of the hosts file depends on your operation system.
Windows XP, Vista and Windows 7 C:\WINDOWS\system32\drivers\etc\hosts
Windows 2000  C:\WINNT\system32\drivers\etc\hosts

Note! Make a backup of the hosts file and put it somewhere safe, in case you mess up.

1. Open the hosts file using Notepad or other plain text editor.
2. Find the line 127.0.0.1 localhost
3. To block, for example, the website youtube.com, add this text under 127.0.0.1 localhost:
   127.0.0.1 youtube.com
4. Save and close the Hosts file.
5. Reboot your computer to apply the changes.
6. Try to open www.youtube.com into a browser.

How to block a website on Internet Explorer

1. Open Internet Explorer and click on Tools
2. Click Internet Options
3. Click on the Content tab
4. Click the Enable button
5. Click on the Approved Sites tab
6. Type the website address you want to block in the box, for example, www.youtube.com
7. Click Never and then OK
8. In the appeared window type and confirm your new password
9. Click on the General tab and make sure to select Users can see websites that have no ratings
10. Click OK

How to block a website in spite of proxy servers

Unfortunately, the hosts file method and blocking a website by using Internet Explorer have a big imperfection. They can be easily bypassed. For example, web-based proxy servers allow getting a blocked website. Also, these methods are not universal and may not fit to a certain computer configuration and a type of a browser. So how to block a website in spite of proxy servers? The best way to block a website is our professional software.

How to block a website using HT Employee Monitor

1. Download and install HT Employee Monitor
2. Click the Block Websites button
3. Click the Add button.
4. In the appeared box, type the website address that you want to block or keyword, for example, youtube.com
5. Click OK


HT Employee Monitor is easy to use and effective, allowing you to restrict user activity and internet usage.
What you can do with HT Employee Monitor:

• Block a website in the most popular browsers (Firefox, Internet Explorer, Opera, Chrome, etc.)
• Block a specific website by URL
• Block a specific website by keywords
• Block a website by categories (Pornography, Gambling, Drugs, etc.)
• Disable any application (instant messengers, browsers, programs, and so on)
• Track and record all your employees' computer activities (launched applications, typed keystrokes, visited web sites, system activity, screenshots and more).

HT Employee Monitor helps you to improve productivity and efficiency of your employees.

আউটসোর্সিং: শুরুটা যেভাবে

আউটসোর্সিং: শুরুটা যেভাবে

  তারিখ: ০৫-০৩-২০১২

আউটসোর্সিং: ইন্টারনেটের মাধ্যমে বিভিন্ন প্রতিষ্ঠান বিভিন্ন ধরনের কাজ করিয়ে নেয়। নিজ প্রতিষ্ঠানের বাইরে অন্য কাউকে দিয়ে এসব কাজ করানোকে আউটসোর্সিং বলে। যাঁরা আউটসোর্সিংয়ের কাজ করে দেন, তাঁদের ফ্রিল্যান্সার বলে। ফ্রিল্যান্সার মানে হলো মুক্ত বা স্বাধীন পেশাজীবী। আউটসোর্সিংয়ের কাজের খোঁজ থাকে, এমন সাইটে যিনি কাজটা করে দেন, তাঁকে বলা হয় কনট্রাকটর (তিনি কনট্রাক্টে কাজ করেন)। আর যিনি কাজ দেন, তাঁকে বলে বায়ার/এমপ্লয়ার (তিনি কনট্রাক্টে কাজ দেন)।
যে ধরনের কাজ পাওয়া যায়: আউটসোর্সিং সাইট বা অনলাইন মার্কেট প্লেসে কাজগুলো বিভিন্ন ভাগে ভাগ করা থাকে। যেমন: ওয়েব ডেভেলপমেন্ট, সফটওয়্যার ডেভেলপমেন্ট, নেটওয়ার্কিং ও তথ্যব্যবস্থা (ইনফরমেশন সিস্টেম), লেখা ও অনুবাদ, প্রশাসনিক সহায়তা, ডিজাইন ও মাল্টিমিডিয়া, গ্রাহকসেবা (Customer Service), বিক্রয় ও বিপণন, ব্যবসাসেবা ইত্যাদি।
ওয়েব ডেভেলপমেন্ট: এই বিভাগের মধ্যে আছে আবার ওয়েবসাইট ডিজাইন, ওয়েব প্রোগ্রামিং, ই-কমার্স, ইউজার ইন্টারফেস ডিজাইন, ওয়েবসাইট টেস্টিং, ওয়েবসাইট প্রজেক্ট ম্যানেজমেন্ট ইত্যাদি।
সফটওয়্যার ডেভেলপমেন্ট: সফটওয়্যার ডেভেলপমেন্টর মধ্যে আছে ডেস্কটপ অ্যাপ্লিকেশন, গেম ডেভেলপমেন্ট, স্ক্রিপ্ট ও ইউটিলিটি, সফটওয়্যার প্লাগ-ইনস, মোবাইল অ্যাপ্লিকেশন, ইন্টারফেস ডিজাইন, সফটওয়্যার প্রকল্প-ব্যবস্থাপনা, সফটরয়্যার টেস্টিং, ভিওআইপি ইত্যাদি।
নেটওয়ার্কিং ও ইনফরমেশন সিস্টেম: এর মধ্যে আছে নেটওয়ার্ক অ্যাডমিনিস্ট্রেশন, ডিবিএ-ডাটাবেজ অ্যাডমিনিস্ট্রেশন, সার্ভার অ্যাডমিনিস্ট্রেশন, ইআরপি/সিআরএম ইমপ্লিমেনটেশন ইত্যাদি।
রাইটিং ও ট্রান্সলেশন: এর মধ্যে আছে কারিগরি নিবন্ধ লেখা (টেকনিক্যাল রাইটিং), ওয়েবসাইট কনটেন্ট, ব্লগ ও আর্টিকেল রাইটিং, কপি রাইটিং, অনুবাদ, ক্রিয়েটিভ রাইটিং ইত্যাদি।
অ্যাডমিনিস্ট্রেটিভ সাপোর্ট: এর মধ্যে আছে ডেটা এন্ট্রি, পারসোনাল অ্যাসিসট্যান্ট, ওয়েব রিসার্চ, ই-মেইল রেসপন্স হ্যান্ডলিং, ট্রান্সক্রিপশন ইত্যাদি।

About Networking

Networking:

Networking means connecting two or more devices (nodes) for communication purpose. A node can be a computer, printer, or any other device capable of sending and/or receiving data generated by other nodes on the network.

Computer Network:

A computer network is a group of interconnected computer or A computer network is any set of computers or devices connected to each other with the ability to exchange data.

Types of networks: 

Local Area Network (LAN): A network covering a small geographic area, like a home, office, or building. Current LANs are most likely to be based on Ethernet technology. For example, a library may have a wired or wireless LAN for users to interconnect local devices (e.g., printers and servers) and to connect to the internet. On a wired LAN, PCs in the library are typically connected by category 5 (Cat5) cable, running the IEEE 802.3 protocol through a system of interconnection devices and eventually connect to the internet.

            Metropolitan Area Network (MAN): A Metropolitan Area Network is a network that connects two or more Local Area Networks or Campus Area Networks together but does not extend beyond the boundaries of the immediate town/city. Routers, switches and hubs are connected to create a Metropolitan Area Network.

              Wide Area Network (WAN): A WAN is a data communications network that covers a relatively broad geographic area (i.e. one city to another and one country to another country) and that often uses transmission facilities provided by common carriers, such as telephone companies.

               Global Area Network (GAN): Global area networks (GAN) specifications are in development by several groups, and there is no common definition. In general, however, a GAN is a model for supporting mobile communications across an arbitrary number of wireless LANs, satellite coverage areas, etc.

                Internetwork: Two or more networks or network segments connected using devices, such as a router. Any interconnection among or between public, private, commercial, industrial, or governmental networks may also be defined as an internetwork. In modern practice, the interconnected networks use the Internet Protocol. There are at least three variants of internetwork, depending on who administers and who participates in them:

• Intranet
• Extranet
• Internet

 Intranet: An intranet is a set of networks, using the Internet Protocol and IP-based tools such as web browsers and file transfer applications, that is under the control of a single administrative entity. That administrative entity closes the intranet to all but specific, authorized users. Most commonly, an intranet is the internal network of an organization. A large intranet will typically have at least one web server to provide users with organizational information.

       Extranet: An extranet is a network or internetwork that is limited in scope to a single organization or entity but which also has limited connections to the networks of one or more other usually, but not necessarily, trusted organizations or entities (e.g. a company's customers may be given access to some part of its intranet creating in this way an extranet, while at the same time the customers may not be considered 'trusted' from a security standpoint). Technically, an extranet may also be categorized as a CAN, MAN, WAN, or other type of network, although, by definition, an extranet cannot consist of a single LAN; it must have at least one connection with an external network.

       Internet: The Internet is a specific internetwork. It consists of a worldwide interconnection of governmental, academic, public, and private networks based upon the networking technologies of the Internet Protocol Suite. It is the successor of the Advanced Research Projects Agency Network (ARPANET) developed by DARPA of the U.S. Department of Defense. The Internet is also the communications backbone underlying the World Wide Web (WWW). The 'Internet' is most commonly spelled with a capital 'I' as a proper noun, for historical reasons and to distinguish it from other generic internetworks.

Participants in the Internet use a diverse array of methods of several hundred documented, and often standardized, protocols compatible with the Internet Protocol Suite and an addressing system (IP Addresses) administered by the Internet Assigned Numbers Authority and address registries. Service providers and large enterprises exchange information about the reachability of their address spaces through the Border Gateway Protocol (BGP), forming a redundent world-wide mesh of transmission paths.

Network topology:

Computer networks may be classified according to the network topology upon which the network is based, such as Bus network, Star network, Ring network, Mesh network, Star-bus network, Tree or Hierarchical topology network, etc.Network Topology signifies the way in which devices in the network see their logical relations to one another. The use of the term "logical" here is significant. That is, network topology is independent of the "physical" layout of the network. Even if networked computers are physically placed in a linear arrangement, if they are connected via a hub, the network has a Star topology, rather than a Bus Topology. In this regard the visual and operational characteristics of a network are distinct; the logical network topology is not necessarily the same as the physical layout.

Open Systems and the Open Systems Interconnection (OSI) model:

A set of protocols that would allow any two different systems to communicate regardless of their underlying architecture is called an open system. The ISO has addressed the problem of allowing many devices to communication and has developed its Open System Interconnect (OSI) model. If fully developed, it would allow any two computers to communicate provided they are connected.

In its most basic form, it divides network architecture into seven layers which, from top to bottom, are the Application, Presentation, Session, Transport, Network, Data-Link, and Physical Layers. It is therefore often referred to as the OSI Seven Layer.

Description of Open Systems Interconnection(OSI) layers

OSI Model
	Data unit	Layer	Function
Host layers	Data	1. Application	Network process to application
		2. Presentation	Data representation and encryption
		3. Session	Interhost communication
	Segment/Datagram	4. Transport	End-to-end connections and reliability
Media layers	Packet	5. Network	Path determination and logical addressing
	Frame	6. Data Link	Physical addressing (MAC & LLC)
	Bit	7. Physical	Media, signal and binary transmission

Network Interface Cards: A network card, network adapter or NIC (network interface card) is a piece of computer hardware designed to allow computers to communicate over a computer network. It provides physical access to a networking medium and often provides a low-level addressing system through the use of MAC addresses. It allows users to connect to each other either by using cables or wirelessly.

1.Repeaters: repeater is an electronic device that receives a signal and retransmits it at a higher level or higher power, or onto the other side of an obstruction, so that the signal can cover longer distances without degradation. In most twisted pair Ethernet configurations, repeaters are required for cable runs longer than 100 meters.

2.Hubs: hub contains multiple ports. When a packet arrives at one port, it is copied to all the ports of the hub for transmission. When the packets are copied, the destination address in the frame does not change to a broadcast address. It does this in a rudimentary way, it simply copies the data to all of the Nodes connected to the hub.

3.Bridges: A network bridge connects multiple network segments at the data link layer (layer 2) of the OSI model. Bridges do not promiscuously copy traffic to all ports, as hubs do, but learns which MAC addresses are reachable through specific ports. Once the bridge associates a port and an address, it will send traffic for that address only to that port. Bridges do send broadcasts to all ports except the one on which the broadcast was received. Bridges learn the association of ports and addresses by examining the source address of frames that it sees on various ports. Once a frame arrives through a port, its source address is stored and the bridge assumes that MAC address is associated with that port. The first time that a previously unknown destination address is seen, the bridge will forward the frame to all ports other than the one on which the frame arrived.

Bridges come in three basic types:

1. Local bridges: Directly connect local area networks (LANs)
2. Remote bridges: Can be used to create a wide area network (WAN) link between LANs. Remote bridges, where the connecting link is slower than the end networks, largely have been replaced by routers.
3. Wireless bridges: Can be used to join LANs or connect remote stations to LANs.

4.Switches: A switch is a device that performs switching. Specifically, it forwards and filters OSI layer 2 datagrams (chunk of data communication) between ports (connected cables) based on the Mac-Addresses in the packets. This is distinct from a hub in that it only forwards the datagrams to the ports involved in the communications rather than all ports connected. Strictly speaking, a switch is not capable of routing traffic based on IP address (layer 3) which is necessary for communicating between network segments or within a large or complex LAN. Some switches are capable of routing based on IP addresses but are still called switches as a marketing term. A switch normally has numerous ports with the intention that most or all of the network be connected directly to a switch, or another switch that is in turn connected to a switch.

5.Routers: Routers are networking devices that forward data packets between networks using headers and forwarding tables to determine the best path to forward the packets. Routers work at the network layer of the TCP/IP model or layer 3 of the OSI model. Routers also provide interconnectivity between like and unlike media (RFC 1812). This is accomplished by examining the Header of a data packet, and making a decision on the next hop to which it should be sent (RFC 1812) They use preconfigured static routes, status of their hardware interfaces, and routing protocols to select the best route between any two subnets. A router is connected to at least two networks, commonly two LANs or WANs or a LAN and its ISP's network. Some DSL and cable modems, for home (and even office) use, have been integrated with routers to allow multiple home/office computers to access the Internet through the same connection. Many of these new devices also consist of wireless access points (waps) or wireless routers to allow for IEEE 802.11b/g wireless enabled devices to connect to the network without the need for a cabled connection.

Protocols:

A protocol is a set of rules that governs data communication to occur. It defines the format and the order of message exchanged between two or more communication entities, as well as the actions taken on the transmission and/or receipt of a message or other event. A protocol defines what is communicated, how it is communicated, and when it is communicated. Without protocol two computer can be connected but not communicate. It is essential to use same protocol for communication between two devices. When several protocols work at a time it is called protocol suit. At present three widely used protocol suits are TCP/IP, IPX/SPX and AppleTalk.

Connection-Oriented and Connectionless services:

When an application uses the connection-oriented service, the client program and the server program send control packets to each other before sending packets with the actual data to be transferred. This so called handshaking procedure alerts client and server, allowing them to prepare for an onslaught of data packets. Once the handshaking procedure is finished, a connection is said to be established between the two end systems. The Internet connection oriented service has a name

-Transmission Control Protocol (TCP); the initial version of TCP protocol is defined in the Internet Request for Comments RFC 793.

There is no handshaking with the Internet’s connectionless service. When one side of an application wants to send packets to other side of the application, the sending program simply sends the packets. Since there is no handshaking procedure prior to data packet transmission, data can be deliver sooner. A source never knows for sure which packets have arrived at the destination. The Internet’s connectionless service is called User Datagram Protocol (UDP); UDP is define in the Internet Request for Comments RFC 768.

Routing Protocols: A routing protocol sends and receives routing information packets to and from other routers. Routing protocols implement algorithms that tell routers the best paths through internetworks. Routing protocols include Border Gateway Protocol (BGP), Interior Gateway Routing Protocol (IGRP), Routing Information Protocol, and Open Shortest Path First (OSPF) to name a few. Routing protocols provide the layer 3 network state update.

Routed Protocols: A routed protocol can be routed by a router, which means that it can be forwarded from one router to another. Such as Internet Protocol (IP), Novell Internetwork Packet eXchange (IPX), and AppleTalk are  routed protocols.

In short, routing protocols route datagrams through a network. Routing is a layer 3 function, thus, routing and routed protocols are network-layer entities. Routing tables on the layer 3 switch (router) are populated by information from routing protocols. A routed protocol will enter an interface on a router, be placed in a memory buffer, then it will be forwarded out to an interface based on information in the routing table.

Routed versus routing protocols:

Confusion often arises between routing protocols and routed protocols. While routing protocols help the router in the decision-making on which paths to send traffic, routed protocols are responsible for the actual transfer of traffic between Layer3 devices. Specifically, a routed protocol is any network protocol that provides enough information in its network layer address to allow a packet to be forwarded from one host to another host based on the addressing scheme, without knowing the entire path from source to destination. Routed protocols define the format and use of the fields within a packet. Packets generally are conveyed from end system to end system.

Internet Address or IP:

IP address is a network layer protocol address for a host in a TCP/IP network. IP address is used to uniquely identify each host in a network. An IP address in the current version of protocol is a 32-bit binary address that uniquely and universally defines the connection of a host or a router to the Internet. IP address is needed in order to communicate with other hosts in the network using the TCP/IP suite of protocols.

IP Addresses are Unique:

The IP addresses are unique in the sense of that each address define one, and only one, connection in the Internet Two device on the internet can never have the same address at the same time.  However, if a device has two connections to the Internet, via two networks, it has two IP address.

IP Addresses are Universal:

The IP addresses are Universal in the sense that the addressing system must be accepted by any host that wants to connected to the Internet.

Originally, an IP address was defined as a 32-bit number and this system, now named Internet Protocol Version 4 (IPv4), is still in use today. However, due to the enormous growth of the Internet and the resulting depletion of the address space, a new addressing system (IPv6), using 128 bits for the address, had to be developed. IPv6 is now being deployed across the world; in many places it coexists with the old standard and is transmitted over the same hardware and network links. This document only covers IPv4.

There are two common notations to show an IP address: Binary notation and dotted decimal notation.

In binary notation, the IP address is displayed as 32 bits. To make the address more readable, one or more spaces is usually inserted between each octet (8 bit). The following example of an IP address. In binary notation:   11000000 10101000 00000000 00000011.

In decimal notation:                 192.168.0.3

Each IP address divided into two parts: Network ID or Netid  +  Host ID or Hostid  

In a specific network, Network ID of each IP address is same but Host ID must be different.

IP versions

Two versions of the Internet Protocol (IP) are in use: IP Version 4 and IP Version 6. Each version defines an IP address differently. Because of its prevalence, the generic term IP address typically still refers to the addresses defined by IPv4. The gap in version sequence between IPv4 and IPv6 resulted from the assignment of number 5 to the experimental Internet Stream Protocol in 1979, which however was never referred to as IPv5.

IPv4 addresses

Main article: IPv4#Addressing

Decomposition of an IPv4 address from dot-decimal notation to its binary value.

In IPv4 an address consists of 32 bits which limits the address space to 4294967296 (2³²) possible unique addresses. IPv4 reserves some addresses for special purposes such as private networks (~18 million addresses) or multicast addresses (~270 million addresses).
IPv4 addresses are canonically represented in dot-decimal notation, which consists of four decimal numbers, each ranging from 0 to 255, separated by dots, e.g., 172.16.254.1. Each part represents a group of 8 bits (octet) of the address. In some cases of technical writing, IPv4 addresses may be presented in various hexadecimal, octal, or binary representations.

IPv4 subnetting

In the early stages of development of the Internet Protocol,^[1] network administrators interpreted an IP address in two parts: network number portion and host number portion. The highest order octet (most significant eight bits) in an address was designated as the network number and the remaining bits were called the rest field or host identifier and were used for host numbering within a network.
This early method soon proved inadequate as additional networks developed that were independent of the existing networks already designated by a network number. In 1981, the Internet addressing specification was revised with the introduction of classful network architecture.^[2]
Classful network design allowed for a larger number of individual network assignments and fine-grained subnetwork design. The first three bits of the most significant octet of an IP address were defined as the class of the address. Three classes (A, B, and C) were defined for universal unicast addressing. Depending on the class derived, the network identification was based on octet boundary segments of the entire address. Each class used successively additional octets in the network identifier, thus reducing the possible number of hosts in the higher order classes (B and C). The following table gives an overview of this now obsolete system.

Historical classful network architecture

Class	Leading bits in address (binary)	Range of first octet (decimal)	Network ID format	Host ID format	Number of networks	Number of addresses per network
A	0	00000000-01111111 0 - 127	a	b.c.d	27 = 128	224 = 16777216
B	10	10000000-10111111 128–191	a.b	c.d	214 = 16384	216 = 65536
C	110

Networking Word

Networking Word

 A
ATN-Asynchronous Transfer Mode

ARPANET-Advance Research Projects Agency Network

ANSI-American National Standards Institute.

ASCII- American Standard Code for Information Interchange.

B

BGP-Border Getaway Protocol

BIW-Business Information Warehouse
BFS-Breath First Search  BIND-Berkeley Internet Name Domain

GPL-General Public License

C

CIDR-Classless Interdomain Routing (CIDR)
CMIP-Common Management Information Protocal

CCNA-Cisco Certified Network Associate

CSU/DSU-Channel Service Unit/Data Service Unit

CSMA/CD-Carrier Sense Multiple Access with Collision Detect
CSMA/CD---Carrier sense multiple access with collision detection
CSMA/CA---Carrier sense multiple access with collision avoidance
CSS-Cascading Style Sheets
CRC-Cyclic redundancy check

UDP-User Datagram Protocol

TCP/IP-Transmission Control Protocol

IGRP-Interior Gateway Protocol

OSPF-Open Shortest Path First

D 
DHCP-Dynamic Host Configuration Protocol

DCE-Data circuit-terminating equipment

DTE-Data terminal equipment
DLCI-Data Link Connection Identifier

DNS-Domain Name System

The Domain Name System (DNS) is a hierarchical distributed naming system for computers, services, or any resource connected to the Internet or a private network. 

A Domain Name Service translates queries for domain names (which are meaningful to humans) into IP addresses for the purpose of locating computer services and devices worldwide.  For example, the domain namewww.example.com translates to the addresses 192.0.43.10 (IPv4) and 2620:0:2d0:200::10 (IPv6).

DSSS-Direct Sequence Spread Spectrum (DSSS)

DFS-Depth-First Search 

DDW-Departmental Data Warehouse

E

ETSI-European Telecommunications Standard Institute

EPROM-Erasable Programmable Read-Only Memory

EE-PROM-Electrically Erasable PROM

F

FTP-File Transfer Protocol

FTAMP-File Transfer and Access Management Protocol 

FCC-Federal Communications Communication

FDDI-Fiber Distribute Data Interface

FAQ-Frequent Asked Question
FAT-File Allocation Table (FAT)

G
GAN-Global Area Network
GOS-Grade of service
H

HTTP-Hyper Text Transfer Protocol

HPC-High Performance Computing

HDLC-High Level Data Link Control

I
ITU-International Telecommunication Union
ILDTS-International Long Distance Telecommunication Service 
IGW-International Getway 

IETP- Internet Engineering Task Force.

IPV4-Internet Protocol Version 4

IPV6-Internet Protocol Version 6

ISO-International Organization for Standardization. 
IEEE-Institute of Electrical & Electronic Engineering
ICMP-Internet Control Message Protocol 
IIR-Infinite Impulse Response
ISD-International Subscriber Dialing
IBM-International Business Machines Company
ISDN-Integrated Service Digital NetworkJ
K
L
LLC-Logical Link Control
M

MAC-Media Access Control

MTSO/MSC-Mobile Telephone Switching Office/Mobile Switching Center

MIN-Mobile Identification Number

MAN-Metropolitan Area Network
MPI-Message Passing Interface
N

NWD-National Wide Dialing

NTFS-New Technology File System

NIC-Network Interface Card
NFS-Network File System
O

OSI-Open Systems Interconnection

P

PCS-Personal Communication Service

PCN-Personal Communication Network

PPP-Point to Point Protocol

PAN-Personal Area Network
PSTN-Public Switch Telephone Network

Q
R

RFC-Request for Comment.

RAID-Redundant Arrays of Inexpensive Disks

RHCE-Red Hat Certified Engineer
RTT-Radio Transmission Technology

S

SDLC-Synchronous Data Link Control Protocol
SSH-Secure Shell
SSH-Secure Shell

STD-Subscriber Trunk Dialling 
SIM-Subscriber Identify Module
SSI-Small Scale Integration
SQL-Structure Query Language 

SMTP-Simple Mail Transfer Protocol

SMB-S Message Block

SONET-Synchronous Optical Network
SNMP-Simple Network Management Protocol

 T
U

USB-Universal Serial Bus

URL-Universal Resource Locator

UMTS-Universal Mobile Telecommunication Service
V

VLSM-Variable Length Subnet Masks (VLSM)

VHE-Virtual Home Entertainment

Virus-Vital Information Resource under Seis

VPN-Virtual Private Network

VSAT-Very Small Aperture Terminal

V-SAT-Very Small Aperture Terminal
VLAN-Virtual LANW

WiMAX-Worldwide Interoperability for Microwave Access

Wi-Fi- Wireless Fidelity

WLAN-Wireless LAN
WARC-World Administrative Radio Conference
WVOIP-Wireless Voice Application
X

XHTML-Extensible Hyper Text Markup Language

XML-Extensible Markup Language

Y
Z

Others

BCD- Binary Coded Decimal

PROM-Programmable Read-Only Memory

LSI-Large Scale Integration

MSI-Medium-Scale Integration

EMI-Electromagnetic Interference

RFI-Radio Frequency Interference

OLAP-Online Analytical Process

EIS-Executive Information System

FOPL-First Order Propositional Logic

ECG-Electro Cardio Grapy

PIN-Personal Indentify Module

FHSS-Frequency Hopping Spread Spectrum (FHSS)

LVM-Logical Volume Management

SPC-Stored-program control