dsl & case study of ucd introduction comparison, dsl & alternative performance provider...
TRANSCRIPT
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
1.544 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
1.544 Mbps duplex on two twisted-pair lines
2.048 Mbps duplex on three twisted-pair lines
12,000 feet on 24 gauge wire
Type of DSL
• SDSL
Symmetric DSL
1.544 Mbps duplex (U.S. and Canada); 2.048 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 ($100-175 install fee)
Satellite access
• Slow and hassle setup with DBS
• Priced services are receive only
• Cost: $179-229 (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: $125-400 (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 - 128 KBPS
DSL - 384 KBPS
DSL - 1.5 MBPS
25 web pages with text and graphics
2.5MB 12 min 2.5 min 52 sec 13 sec
A 20-second video
8MB 37 min 8.5 min 2.75 sec 43 sec
Download software
25MB 120 min 26 min 8.5 min 2.2 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
• RegulationLocal Phone company requires installation of new phone line."Line Sharing" will be most likely passed in November, 2000.
• Bureaucracies and Mergers in RBOC GTE and Bell Atlantic WorldCom and MCIAT&T and British Telcom
Problems in DSL for the User side
• Time Issue for setting up DSL
DSL: 24 - 48 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 WorkHome
ATM
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, 132.194.200.3 for 1/100 PVC
To the campus
IP address information:- 132.194.x.x, class B, belonging to UCD- 255 subnets for the whole campus- 4-5 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 (1-877-236-8169) 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) 556-6100• Internet: