Ken@cup.portal.com (10/27/89)
Communications Week had some hard info on communications right
after the quake. Here are some extracts:
The quake hit at 5:04PM.
Within hours, Pac Bell was seeing 1 million call attempts
*per minute*!
AT&T reported 17 million call attempts between 2AM and 10AM
the following day.
Pac Bell Cellular reported 10 times normal calling volume.
AT&T reported 144.7 million calls nationwide for the 24 hour
period starting midnight. 27.8 million were directed into the
bay area with 9.5 million completed.
AT&T let 70% of the outgoing calls complete giving the rest a
recording. AT&T let 30% of the incoming calls complete.
MCI blocked 50% of the incoming calls to the three area codes
affected. MCI has a system network capacity 120-150% higher than
average peak loading.
Sprint blocked dynamically with the blocking adjusted at a 5 minute
rate. Switches generating the most traffic were blocked at 60%. Less
busy switches were blocked at 10, 20 and 45% levels.
Seven out of 60 Pac Tel Cellular cells were knocked out. Four were
restored quickly - the rest are still out.
GTE Mobilnet had only 2 cells down out of 80.
All in all, I think all the carriers performed admirably. Pac Bell had
completed a quake drill Aug 3. Ironically enough - they simulated a
7.0 quake in San Jose. The actual quake was 6.9 with a center only 20
miles away.
MCI's capacity surprised me (120-150% of peak). I rather suspect
AT&T's is much high than that.
ken@cup.portal.com