11/7: Telecom & Networking, cont. Network services –ISDN, DSL, Cable modems, etc. –Which to use? ATM E-Commerce & E-Business technologies EDI: Electronic Data Interchange available services, etiquette

Network Services Packet switching (X.25) Frame relay Asynchronous Transfer Mode (ATM) Integrated Services Digital Network (ISDN) Digital Subscriber Line (DSL) Cable modem T1, T3 lines

Packet Switching (X.25) Older form of running LANs Data-only network Works well in small groups Becomes inefficient and slow as network expands Breaks transmitted data into packets of 128 bytes each Sends them, checking for transmission errors

Frame Relay Another data-only network (well, a few newer ones have voice) Variable length link-layer frames. Less overhead than X.25 Higher speed than X.25 Higher capacity than X.25 Common setup today for LANs and WANs

Asynchronous Transfer Mode (ATM) Synonym: Cell Relay. Not data-only: can transmit voice, video, data, images, etc. Seen as the eventual replacement for X.25 & Frame Relay, as well as ISDN. Transmits “cells” of 53 octets (8 bytes).

ISDN: Integrated Services Digital Network International standard for transmitting voice, video, data over public telephone lines. Older system, being rapidly replaced with DSL. Transmits at 128 Kbps Costs about $ / month. Installation costs: See more information at dInfo_1/1,1973, ,00.html dInfo_1/1,1973, ,00.html

DSL: Digital Subscriber Line Also uses public telephone lines Transmission speeds: Downstream: 384 Kbps – 1.5 Mbps Upstream:128 Kbps Costs about $ / month (SWBell) Installation: $ 0.00 (if you “self-install”) + equipment $99.00

Cable Modem Uses cable television lines Transmission speeds: (depends on choice of service) Downstream: 256 Kbps – 1 Mbps Upstream: 64 Kbps – 256 Kbps – – / mth + $10.00 for basic cable (Charter Comm.) Installation:$ equipment $5.00 /mth More info (no pricing) at ernet.asp ernet.asp

T1, T3 lines Dedicated telephone line for data service Transmission speeds: T1: 24 channels at 64 Kbps/ea = Mbps total (can also buy a portion of a T1 line) T3: 672 channels, 64 Kbps/ea = 43 Mbps total Costs at least $ 499/mth for T1, lots more for T3 Installation:$ ??? More info at

E-Commerce & E-Business Tools Electronic mail ( ) Voice mail Facsimile machines (fax) Teleconferencing Dataconferencing Videoconferencing Groupware Electronic Data Interchange (EDI)

Electronic Data Interchange Computer – to – computer exchange between two organizations of standard business transaction documents COMPUTER SELLERCUSTOMER ORDERS, PAYMENTS SHIPPING NOTICES, PRICE UPDATES, INVOICES

General Considerations address: electronic mail vs. “snail mail” programs for Netscape Messenger, MS Outlook, Eudora messages reside on the server until downloaded by the user

Your SLU forwarding your SLU to another account –use Telnet.exe –directions available at –MAIL> SET FORWARD using

To:, CC:, BCC: Reply-To: CC to self Attaching files

Etiquette awareness of conventions is important essence of immediacy remember: is never dead… –messages are easily forwarded –messages are used as proof “That’s not what I meant” –think and pause before you send it –context and nuance are lost in –easily perceived as rude, offensive, or harsh :-)

Etiquette: Dos & Don’ts DO use for general announcements DO use to congratulate people and “quick hellos” DON’T use to complain, gripe, or argue: talk in person DON’T use for confidential information :-) ;-)

Etiquette: Dos & Don’ts DO say hello DO sign your name DON’T use all capital letters: All capitals = SHOUTING in DO use emoticons or make it plain that you are jokingemoticons DON’T leave all the headers on a message you plan to forward :-) ;-) :->