DSL & Case Study of UCD Introduction Comparison, DSL & Alternative Performance Provider & Users & Problems Case Study

DSL(Digital Subscriber Line) A new technology for bringing high- bandwidth over copper telephone line. A service which allows you to use internet and phone in the same time A service which allows you connect to ISP without changing from analog to digital and from digital to analog.

Type of DSL ADSL Asymmetric Digital Subscriber Line to 6.1 Mbps downstream; 16 to 640 Kbps upstream CDSL Consumer DSL from Rockwell 1 Mbps downstream; less upstream 18,000 feet on 24 gauge wire

Type of DSL HDSL High bit-rate Digital Subscriber Line Mbps duplex on two twisted-pair lines Mbps duplex on three twisted-pair lines 12,000 feet on 24 gauge wire

Type of DSL SDSL Symmetric DSL Mbps duplex (U.S. and Canada); Mbps (Europe) on a single duplex line downstream and upstream 12,000 feet on 24 gauge wire

By Performance and Cost Digital Subscriber Line (DSL) Analog dial up modems Cable Modem Satellite Access Integrated Services Digital Network (ISDN)

DSL Provide higher data rate SDSL, ADSL, VDSL Differences in wire gauge effects performance Impulse noise and disturbances affect transmission rate Maximum length< 2000 Cost: relative to the performance $40-875/ month (plus $110 installation fee)

Analog Dial up modem Quality of line is good Most for individual PC users The problems caused by congestion Cost: Cheap cost and compatibility

Cable Modems Primary competitor to DSL Used primary for residential Internet access Always on and high speed Internet access Two types: HFC and one-way modem Upgrade line is expensive Basic structure is different from DSL Cost: $ 40-60/ month ($ install fee)

Satellite access Slow and hassle setup with DBS Priced services are receive only Cost: $ (Install), $350 (dish and modem) Service fee: $20-25/month

ISDN Like DSL, gives 3 data channels Widely available AO/DI is useful for low bandwidth Complex Cost: $ (install and setup), $20-80 (service)

Performance – How it works Traditional Phone service - Analog signal Ordinary modems (56K, ISDN) - Analog changes to Digital DSL - Digital to Digital - Use your phone and PC on the same line and at the same time

Performance – How fast it is Dependent on The Distance The Quality of the line The Price (600k) The Quality of your provider’s connection to the Internet (routers, backbone)

Performance – How fast it is Download (25MB under 3 min) Browse (25webpages in 13 sec) TYPE OF DATA FILE LENGTH 28.8 KBPS MODEM ISDN KBPS DSL KBPS DSL MBPS 25 web pages with text and graphics 2.5MB12 min2.5 min52 sec13 sec A 20- second video 8MB37 min8.5 min2.75 sec43 sec Download software 25MB120 min26 min8.5 min2.2 min

Major DSL Providers in Colorado AT&T Concentric Covad Flashcom JATO: Serving in Boulder. MCI/UUNet Northpoint Rhythms US West: The Largest DSL Provider in Colorado Verio

Problems in DSL for the User side Regulation Local Phone company requires installation of new phone line. "Line Sharing" will be most likely passed in November, Bureaucracies and Mergers in RBOC GTE and Bell Atlantic WorldCom and MCI AT&T and British Telcom

Problems in DSL for the User side Time Issue for setting up DSL DSL: hours T-1: 4 hours Management Capability in DSL Disaster recovery Redundancy and Performance Monitoring capabilities

Problems in DSL for the User side Security Issue of DSL Pacific Bell case "Anybody could easily access to his confidential files because his PC has a file-sharing feature." Solution 1: Security Software Solution 2: Education about Internet Security

Background Mainly use Dial-Up networks 15 T-1; 23 connection lines; 53 Kbps Only 33.3 Kbps for actual Why Implement DSL, What Kind of DSL Faster than ISDN Cheaper than Cable Modem Implementing ADSL; 640 Kbps downstream and 256 Kbps upstream

With Whom and How Much US West Lease more 3 Mbps on ATM separate pipe of DSL Leasing cost around $1,000 a month More manpower for clerical works not technical supports Only two weeks to implement DSL

DSL Network Configuration in UCD UCD is located far from its local TeleCo 4 km. 18,000 feet from the TeleCo UCD uses ATM modems UCD uses Bridging and Static IP addressing mode not DHCP and Dynamic IP addressing mode

How It Work Home ATM WAN Router UCD Campus DSL FRGP Router (Front Range Giga Pop) Internet DSL Circuit OC-3, 155 Mbps (3Mbps PVC that UCD is using) 75 Mbps, 25 Mbps reserved for UCD DSL Network Configuration in UCD To Internet To match IP address with the PVC number, for example, for 1/100 PVC To the campus IP address information: x.x, class B, belonging to UCD subnets for the whole campus subnets for DSL services

Difficulties and Benefits for Users Difficulties in DSL installing process Solved by providing the instruction Major Benefits: –Faster Connection, –Always On, –No Downtime

Procedure for Users to Install DSL Contact US West ( ) and identify yourself as a UCD user Order DSL service from US West (Line Connection) Go to CINS office (North Classroom 2514) Fill out the form Wait for and install devices provided by US West (DSL Modem, Microfilter, etc.)

Information provided by Dr. Randy Hagan - A Principal Software Programmer under the computing, information and network services in UCD Location: 1200 Larimer Street, NC 2506 Office: (303) Internet: er.edu