virtual community csc1720 – introduction to internet essential materials

Virtual CommunityVirtual Community

CSC1720 – Introduction to CSC1720 – Introduction to InternetInternet

Essential MaterialsEssential Materials


All copyrights reserved by C.C. Cheung All copyrights reserved by C.C. Cheung 2003.2003.

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OutlineOutline

Mailing listMailing list Instant Messaging (Instant Messaging (IMIM)) Bulletin BoardsBulletin Boards Internet Relay Chat (Internet Relay Chat (IRCIRC)) Web-based ChatWeb-based Chat Multi-User Dungeon (Multi-User Dungeon (MUDMUD)) Internet TelephonyInternet Telephony How do they work?How do they work?



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What is mailing list?What is mailing list?

Uses a mail address for disseminating Uses a mail address for disseminating newslettersnewsletters. . More importantly, for disseminating More importantly, for disseminating discussionsdiscussions. . A centrally maintained mailing list is desirable. A centrally maintained mailing list is desirable. This is typically implemented by a This is typically implemented by a mail reflectormail reflector. . Those people on the mailing list are called the Those people on the mailing list are called the

subscriberssubscribers.. We can easily create FREE mailing lists for :We can easily create FREE mailing lists for :

– Sharing files.Sharing files.– Keeping in touch with family or friends.Keeping in touch with family or friends.– Discussion groupsDiscussion groups



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Mailing list illustrationMailing list illustration

Reference: www.learnthenet.comReference: www.learnthenet.com

Any questions?



55

Mail ReflectorMail Reflector

An An e-mail reflectore-mail reflector is a program that is a program that performs the forwarding broadcaster performs the forwarding broadcaster of e-mail on the name of a discussion of e-mail on the name of a discussion list.list.

How it works?How it works?– One member of the discussion list sent an One member of the discussion list sent an

email to the list.email to the list.– The email reflector receives the message The email reflector receives the message

and automatically forwards a copy of the and automatically forwards a copy of the email to each person on the discussion list.email to each person on the discussion list.



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Subscription method Subscription method (I)(I) Historically, the Internet uses special Historically, the Internet uses special

addresses for administrating subscription addresses for administrating subscription requests. requests.

Such an address has the same name as the Such an address has the same name as the mailing reflector, but with the suffix mailing reflector, but with the suffix -request-request added. added.

For example, For example, [email protected] [email protected] The list maintainer must read the requests The list maintainer must read the requests

and edit the mailing list manually. and edit the mailing list manually.



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Subscription method Subscription method (II)(II) Originally from BITNET. Originally from BITNET. Maintain mailing list without human intervention. Maintain mailing list without human intervention. To subscribe, send a specially formatted message to a special To subscribe, send a specially formatted message to a special

address. For example:address. For example:

QUESTION - How can listserv know your address? QUESTION - How can listserv know your address? To unsubscribe:To unsubscribe:

– With listserv, unsubscribe is done by sending a mail with the With listserv, unsubscribe is done by sending a mail with the following content: following content:

– signoff marsmansignoff marsman

To:To: [email protected]@cse.cuhk.edu.hk

Subject:Subject: (no subject)(no subject)

Mail-body:Mail-body: subscribe marsman Ray Cheungsubscribe marsman Ray Cheung



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Subscription method Subscription method (III)(III)

Fill in your Fill in your e-mail e-mail address via address via the the WebPages.WebPages.Subscribe

Unsubscribe



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How does it work?How does it work?Subscribe a listSubscribe a list

[email protected]

Create a list

List owner

List member

Subscribe to list

List member

Subscribe to list

List member

Subscribe to list



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How does it work?How does it work?Post email to a listPost email to a list

[email protected]

List owner

List member

List member

List member

Post email

Receive email

Receive email

Receive email

Receive email



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How does it work?How does it work?Unsubscribe a listUnsubscribe a list

[email protected]

List owner

List member

List member

List member

Post email

Receive email

Receive email

Receive email

unsubscribe

Acknowledgement



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Mailing list - SummaryMailing list - Summary

List List typetype

Subscription Subscription AddressAddress

Subscription Subscription MessageMessage

Termination Termination MessageMessage

Posting Posting AddressAddress

ListservListserv listserv@hostnamelistserv@hostname subscribe subscribe listlist your your namename

signoff signoff listlist list@hostnamelist@hostname

MajordomoMajordomo majordomo@hostnamemajordomo@hostname subscribe subscribe listlist your your namename

unsubscribe unsubscribe listlist list@hostnamelist@hostname

InternetInternet list-request@hostnamelist-request@hostname AnythingAnything AnythingAnything list@hostnamelist@hostname

AlmanacAlmanac almanac@hostnamealmanac@hostname subscribe subscribe listlist unsubscribe unsubscribe listlist list@hostnamelist@hostname



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Mailing list – Mailing list – Listserv / MajordomoListserv / Majordomo



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Subscription MessageSubscription Message

How to unsubscribe?



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Search mailing list – Search mailing list – Catalist, LisztCatalist, Liszt



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CUHK Mailing listCUHK Mailing list

Subscribe /Unsubscribe

Reference



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How to apply?How to apply?http://www.cuhk.edu.hk/itsc/network/app/maillist/index.html



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Mailing list NetiquetteMailing list Netiquette

Keep in short.Keep in short. Your topic is relevant to the list.Your topic is relevant to the list. Never send personal messages to the whole Never send personal messages to the whole

list, but to individuals.list, but to individuals. Clearly separate facts and opinions.Clearly separate facts and opinions. Avoid insulting anyone.Avoid insulting anyone. Include your full name & email address in the Include your full name & email address in the

signature.signature. Don’t include email attachments.Don’t include email attachments. Don’t use auto-reply.Don’t use auto-reply.



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Mailing list digestsMailing list digests

A very busy mailing list will provide a A very busy mailing list will provide a digest available for members to request digest available for members to request instead of the regular list.instead of the regular list.

A digest is the compilation of all the A digest is the compilation of all the messages that are received to that messages that are received to that particular group a day or a week.particular group a day or a week.

If you do not want to bother with a If you do not want to bother with a bunch of email messages on a real-time bunch of email messages on a real-time basis, otherwise, please select basis, otherwise, please select individual ones.individual ones.



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Comparison betweenComparison betweenMailing list & Mailing list & NewsgroupNewsgroup

Mailing ListMailing List NewsgroupNewsgroup

CoverageCoverage Limited to those on a Limited to those on a mailing listmailing list

Unlimited coverageUnlimited coverage

OrganizatioOrganizationn

Intermingle into the mail Intermingle into the mail boxbox

Well organized into different Well organized into different newgroups, e.g. newgroups, e.g. rec.music.folks, cuhk.forum, rec.music.folks, cuhk.forum, cuhk.cse.csc1720cuhk.cse.csc1720

VolumeVolume Varies, but all stored in Varies, but all stored in user’s storage spaceuser’s storage space

Huge, but do not require Huge, but do not require storage of individual userstorage of individual user

CommitmeCommitmentnt

Committed, until un-Committed, until un-subscriptionsubscription

Participating into a news Participating into a news group at user’s discretiongroup at user’s discretion

DistributioDistribution speedn speed

Virtually instantaneousVirtually instantaneous SlowSlow



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Instant Messaging (IM)Instant Messaging (IM)

Instant Messaging (IM) has gained Instant Messaging (IM) has gained popularity becausepopularity because– Rapid response of email is not fast enough.Rapid response of email is not fast enough.– No way to know the receiver is online or not.No way to know the receiver is online or not.– Many steps to send email back and forth Many steps to send email back and forth

with the same person.with the same person. We have to maintain a list of people that We have to maintain a list of people that

you want to contact withyou want to contact with– Buddy list / Contact listBuddy list / Contact list



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Instant MessagingInstant Messaging

A variety of special featuresA variety of special features– Instant MessageInstant Message – sending messages back – sending messages back

and forth with an online friendand forth with an online friend– ChatChat – creating your own chatroom with – creating your own chatroom with

your friend(s)your friend(s)– Web linksWeb links – sharing your favorite links with – sharing your favorite links with

your friendsyour friends– FilesFiles – sending file to your friend directly – sending file to your friend directly– TalkTalk – Using Internet to talk to your friend. – Using Internet to talk to your friend.– Real-time informationReal-time information – retrieving real- – retrieving real-

time stock or other quotes.time stock or other quotes.



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How does it work?How does it work?

Step 1: establish a connection with the IM server

Step 2: Send instant messages to your online friend(s) on the list.

IM server

IM clientIM client

IM client



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Instant Messaging - Instant Messaging - FiguresFigures



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Trillian – multi-chat Trillian – multi-chat clientclient Support for IRC, AIM, ICQ, MSN, Yahoo Messenger.Support for IRC, AIM, ICQ, MSN, Yahoo Messenger.



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Instant Messaging and Instant Messaging and Presence Protocol Presence Protocol (IMPP)(IMPP)

MaintaineMaintained by IETFd by IETF

So have So have you tried you tried IM?IM?



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Bulletin Boards (BBS)Bulletin Boards (BBS)

A bulletin board is a web site.A bulletin board is a web site. There is a computer hosting the There is a computer hosting the

bulletin board.bulletin board. You can use menus to navigate the You can use menus to navigate the

board’s contents.board’s contents. You can post /follow-up /view /modify You can post /follow-up /view /modify

articles (or insert pictures) on the articles (or insert pictures) on the board.board.

Threading control.Threading control.



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Bulletin Boards (BBS)Bulletin Boards (BBS)



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BBSBBS Reference



3030

Internet Relay Chat Internet Relay Chat (IRC)(IRC) IRC is the original chat medium on the IRC is the original chat medium on the

Internet. IRC is worldwide.Internet. IRC is worldwide. More than 100,000 people are chatting More than 100,000 people are chatting

online at any given hour.online at any given hour. IRC isIRC is

– Multi-userMulti-user– Multi-channel chat systemMulti-channel chat system

Each user has a nickname and they Each user has a nickname and they can talk to other users either in can talk to other users either in privateprivate or on a or on a chatroomchatroom..



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How to use IRC?How to use IRC?

Client & Server modelClient & Server model IRC clients are available for IRC clients are available for

different platforms, PC, different platforms, PC, Macintosh, or UNIX.Macintosh, or UNIX.

Macintosh IRC clientMacintosh IRC client– IrcleIrcle

Windows based IRC clientWindows based IRC client– mIRCmIRC– Easy to use, highly configurableEasy to use, highly configurable



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IRC ClientsIRC Clients

You can You can use use different different Operating Operating System to System to connect to connect to the IRC the IRC network.network.

Reference



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IRC server IRC server

Clients

Clients



3434

How Do we connect?How Do we connect?

IRC network is a IRC network is a collection of collection of serversservers linked together. linked together.

To use IRC, we should connect to To use IRC, we should connect to one of the IRC server.one of the IRC server.

All servers on a network have the All servers on a network have the access to the same information.access to the same information.

Depends on your geographical Depends on your geographical location to choose your IRC server location to choose your IRC server in the IRC network.in the IRC network.



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IRC commandsIRC commands

If you are connected, you need to join If you are connected, you need to join a channel (chat room).a channel (chat room).

A Channel is a place that group A Channel is a place that group conversation occurs.conversation occurs.

All IRC commands are preceded by the All IRC commands are preceded by the forward slash “/”.forward slash “/”.– JOINJOIN – to join a channel – to join a channel– QUITQUIT – exit your IRC session – exit your IRC session– NICKNICK – change your nickname – change your nickname

IRC Etiquette – keep in mind.IRC Etiquette – keep in mind.



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IRC - FigureIRC - Figure



3737

Chat Online?Chat Online?

RequiredRequired– An Internet connectionAn Internet connection– The proper softwareThe proper software– Lots of patienceLots of patience– A common languageA common language– Basic literacy skillsBasic literacy skills– A good dispositionA good disposition– A high tolerance for meeting A high tolerance for meeting

different kind of people imaginable.different kind of people imaginable.



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MUD – Multi-User MUD – Multi-User DungeonDungeon MUDMUD is also called “Multi-User Domain” is also called “Multi-User Domain” It is a computer program which allows It is a computer program which allows

users to login and explore.users to login and explore. Each user takes control of a special Each user takes control of a special

character. (You can walk around, chat, character. (You can walk around, chat, … )… )

MUD is Real-time chat forum and has MUD is Real-time chat forum and has multiple locationsmultiple locations– e.g. e.g. combat, traps, puzzles, magiccombat, traps, puzzles, magic

Implicitly reserved for game-oriented.Implicitly reserved for game-oriented. Some other social MUD are called “MU*”Some other social MUD are called “MU*”



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Top MUD sitesTop MUD sites



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MUD figuresMUD figures

You can walk, chat, attack, defense, …You can walk, chat, attack, defense, …



4141

Web-Based ChatWeb-Based Chat

With the development of Java-based With the development of Java-based servers, browser plug-ins and HTML-servers, browser plug-ins and HTML-based chat.based chat.

Simply means – Chatting on the webSimply means – Chatting on the web Easy to use – chat everywhereEasy to use – chat everywhere You should first create an accountYou should first create an account Login and then join the chat Login and then join the chat

session.session.



4242

Web-based Chat - Web-based Chat - FiguresFigures



4343

Yahoo! Group?Yahoo! Group?

Share files, photos, mailing list, …Share files, photos, mailing list, …



4444

Internet Phone CallsInternet Phone Calls

Making telephone calls by using the Internet.Making telephone calls by using the Internet. Your voice is digitalized and broken down Your voice is digitalized and broken down

into IP packets for routing.into IP packets for routing. 2 ways for communication2 ways for communication

– Making calls via your PC (PC phone call)Making calls via your PC (PC phone call)– Internet Telephony (Voice over IP)Internet Telephony (Voice over IP)

Make a phone call same as you pick up the Make a phone call same as you pick up the telephone, except your call is routed over the telephone, except your call is routed over the Internet rather than the original telephone Internet rather than the original telephone system.system.

Cut the price for Long distance calls.Cut the price for Long distance calls.



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PC phone callsPC phone calls

Connect to the Internet.Connect to the Internet. Start the special phone software which allows Start the special phone software which allows

you to connect to a special directory.you to connect to a special directory. The directory stores a list of people who have The directory stores a list of people who have

the particular phone software, and their IP the particular phone software, and their IP addresses.addresses.

You can lookup someone’s name of the You can lookup someone’s name of the directory in order to retrieve his/her IP address.directory in order to retrieve his/her IP address.

The communication channel will be digitalized.The communication channel will be digitalized.– The software breaks up the voice into special packets The software breaks up the voice into special packets

which will be sent over the Internet by using TCP/IP which will be sent over the Internet by using TCP/IP protocol.protocol.



4646

Microsoft Microsoft NetMeetingNetMeeting Support video and Support video and

audio conferencing.audio conferencing. View the Internet View the Internet

Directory, and review Directory, and review a list of people a list of people currently running currently running NetMeeting. NetMeeting.

Use NetMeeting's Use NetMeeting's address book to place address book to place calls.calls.

•



4747


John

Peter

Lookup Peter’s nameIn the directory and getPeter’s IP address

IP packets

1) Voice signal converted into binary data2) Compress the data3) Divided into small IP packets for transmission

Arrived out of orderMissing packetsConvert to voice signals



4848

Internet TelephonyInternet Telephony

Use normal telephone (but not a computer) to Use normal telephone (but not a computer) to make a phone call using IP telephony.make a phone call using IP telephony.– You might have to dial a special code first.You might have to dial a special code first.

The first part use the normal Public Switched The first part use the normal Public Switched Telephone Network (PSTN).Telephone Network (PSTN).

The call is sent to a special IP voice gateway The call is sent to a special IP voice gateway which converts voice signal to digital data, which converts voice signal to digital data, compress it, digitize voice signal to IP packets.compress it, digitize voice signal to IP packets.

The IP packets are sent to another IP voice The IP packets are sent to another IP voice gateway which is closed to the phone call gateway which is closed to the phone call destination.destination.

The quality is slightly worst then normal phone The quality is slightly worst then normal phone call.call.



4949

PSTN connectionPSTN connection



5050

Internet Telephony -Internet Telephony -How does it work?How does it work?

JohnMaryInternet

IP packets IP packetsIP voicegateway

IP voicegateway



5151

Internet Phone - Internet Phone - FiguresFigures



5252

Voice over IP Voice over IP (VoIP)(VoIP) Voice over IPVoice over IP application application

combines the legacy voice combines the legacy voice networks and packet networks by networks and packet networks by allowing both voice and signaling allowing both voice and signaling information to be transported information to be transported over the packet network, the over the packet network, the Internet.Internet.

•



5353

VoIP DevicesVoIP Devices



5454

Unified NetworkUnified NetworkTelephone + InternetTelephone + Internet



5555

Why is VoIP so Why is VoIP so attractive?attractive? Quote from Nortel NetworksQuote from Nortel Networks Save money:Save money: You can use your existing WAN to You can use your existing WAN to

transport internal voice traffic. Where traditional voice transport internal voice traffic. Where traditional voice lines are expensive - international calls, for example - lines are expensive - international calls, for example - the cost savings can be immense. the cost savings can be immense.

Simplify:Simplify: Where voice and data run on the same Where voice and data run on the same network, you can expect significant operational network, you can expect significant operational improvements. It's far easier to change IP terminals, improvements. It's far easier to change IP terminals, for example. for example.

Add value:Add value: The most interesting benefits will come The most interesting benefits will come from innovative applications and e-business from innovative applications and e-business integration, increasing productivity, customer loyalty integration, increasing productivity, customer loyalty and competitiveness. and competitiveness.



5656

SummarySummary

Virtual CommunitiesVirtual Communities– Newsgroup, Mailing listNewsgroup, Mailing list– Instant Messaging (IM)Instant Messaging (IM)– Bulletin Boards (BBS)Bulletin Boards (BBS)– Internet Relay Chat (IRC)Internet Relay Chat (IRC)– Multi-User Dungeon (MUD)Multi-User Dungeon (MUD)– Web Based ChatWeb Based Chat

Internet Phone CallsInternet Phone Calls– PC-PC calls, Internet TelephonyPC-PC calls, Internet Telephony

Cisco - VoIPCisco - VoIP Thank you for your patience!Thank you for your patience!

Can you comparethem based on“Easy to use”,

“Convenience”,“etc…”?

virtual community csc1720 – introduction to internet essential materials

Documents

maintained mailing list

discussion list

mailing reflector

list maintainer

free mailing lists

mail address

internetall copyrights

email reflector