26-January-2000
Mizzou Linux Users Group
AT&T Cable
AT&T @Home Cable
Service
Overview
- What is AT&T @Home Cable?
- High speed Internet access through standard
television cable
- Anywhere AT&T cable television service can be
utilized AT&T @Home can be as well
- Service 100 percent launched in Columbia
- Installation within four weeks of intitial call
- Up to four IPs per cable modem
- Special deal: $19.95 for three months now
Technical Description
- Connection to service
- Computer connects to cable modem via ethernet
card
- Cable modem connects to fiber node (each fiber
node is equivalent to LAN) which converts signal
from RF to light
- Fiber node connects to head end
- Head end connects to Regional Data Center (R.D.C.)
via OS-3
- R.D.C. connects to Network Access Point (N.A.P.)
- N.A.P. goes out to Internet
- R.D.C connected together via OC-43 lines
- Data transfer
- Data moves accross modem in Frequency Modulation
- Modem data encrypted with 56 bit DES encryption
- Data moves upstream at speeds around 1 m.b.p.s at
fastest but much slower downstream
Why to Chose a Cable Modem
- Alternatives
- ASDL from Socket costs $10 more per month and
performance decreases as distance increases
- T1 Line is too costly
- 56 k.b.p.s. modem not fast enough
Problems and Issues
- No linux support
- Traffic issues
- Designed to handle 50,000 people (expandable)
- Speed decreases as more people use service on
fiber node (peak time 5-10 p.m.)
- Number of computers on service
- Up to four computers only (including Sega
Dreamcast)
- No computers outside premisis
- Packet sniffing
- All packets encrypted with 56 bit DES encryption
Last modified 16-Feb-2000
Neil Bradshaw