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Advanced Topics in Computer Systems |
9/24/01 |
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Anthony Joseph & Joe Hellerstein |
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Areas
· Systems: HW, OS, Applications, …
· Communications: Network, Phones, …
· Data: Storage, Mgmt, Electronic versus non-Electronic format
Some issues:
· Real-time vs non-real-time business
o Factory w/ JIT, Financial, Tax acct
o Healthcare versus fast-food
o Governmental agencies
· Amount and type of business data
o Paper - what to do with it? Scan it!
o Bits and bytes - how accessed?
§ r/o or r/w?
§ Sharing?
· Scope and scale of expected disaster
o Local, state, regional
· Type of disaster and disruption
o Earthquake, Flood, Hurricane, Rolling power outage, Terrorist, …
· Size of business
o One location versus multi-national (can leverage other locations)
· Type of communication
o Telephone, fax, internet, cellular, wireless device
· Hot site (reserved for the bigger companies)
o Identical hardware (tape drive, backup software)
o Can range from shared room to entire building/campus
o Can be expensive (value of WTC infrastructure >$7 billion)
· Cold site
o Private or rented
o IBM's facility received first call at 9:10 (22 minutes after first plane hit)
o IBM: 175K sq ft, four stories
o Fees range from $100/month to $1 million for recovery plan
· Leverage off other locations of your company
· What can smaller businesses do?
· Data management options
o Real-time data replication (East coast / west coast)
§ Expensive! $100K/month at least
§ Most common for financial companies
§ Only about 250 companies nationwide
o Instant fail-over (activated by many large WTC companies)
§ Example Morgan Stanley has hot site in Teaneck NJ
o Nightly tape (or physical disk) backup with off-site storage
§ Iron Mountain has 33 WTC customers storing data in Moonachie NJ (13 miles away). Sent drives to IBM cold site
§ How to reach storage facility?
§ Time to recover?
o Less frequent backup
§ Empire Blue Shield (largest health insurer in NY)
§ Scans all documents, lost previous two weeks work
· Volume of calls, types of lines
o Verizon's West St facility supported 200K voice lines, 3 million private lines (ring-down circuits and leased data lines)
§ Ring-down circuits (dedicated point-to-point voice versus speed dial)
o Verizon rerouted 24 OC-48 circuits (20 Million T1s)
· Dynamic fail-over at physical layer
o SONET (Synchronous Optical Network)
o Dual redundant optical links arranged in bi-directional ring topology
o Doesn't help when attached equipment is destroyed
· WTC buildings contained two phone switches each capable of supporting a large city
· Real-time recovery versus afterwards
o Government agencies
o Web site traffic increased to 160K/day for White House
o Navy and army hit 205K and 137K
o FBI collected 66K tips in 10 days
o FEMA (no real traffic normally) hit 88K
· Many large companies operating within one day
· Healthcare, insurance, financial, …
· Network management
o Very little Internet infrastructure damaged in WTC disaster
o But, incredible demand for information
o E-mail, IM as communication alternatives
o Loss of two of three over the air networks in NYC
§ NBC, ABC had facilities only on WTC
§ CBS had backup on Empire State building
§ WNBC streamed 300K feed
§ ABCNEWS streamed 56K feed
· Cellular
o 40% US penetration rate
o Played pivotal role in WTC disaster
o Withstood high demand and significant damage
§ More resilient than fixed infrastructure – mobile!
o Verizon alone lost 10 cellular towers
o Replaced seven sites in NYC, added two in DC, one in PA using Cells On Wheels in hours
§ Versus predicted 90-days to replace fixed residential lines
o Incorporates priority scheduling for overload conditions
§ 911 ranked higher than ordinary calls
o High demand for satellite phones (DISA bought 20K Iridium handhelds last year)
· Telephone
o Verizon lost major telco exchange and routing capability
o Also lost Broad st office (80% of Nasdaq lines)
o Traffic of 340 million calls/day (double normal)
o Prioritized outgoing traffic over incoming traffic
o Two-fifths of Pentagon damaged, but internal PBX remained internally operational
§ But, affected by Verizon cellular problems