Learning by Doing: CISCO Certified Network ... - SCN Research

CSU/DSU
CSU/DSU—Channel Service Unit/Data Service
Unit…from the “WAN cloud” into this and then into your
router.
PIX Firewall—Security device. Only works with IP. All
other protocols must be tunneled through it…so what’s the
point of having it?
Small PBX—mini telephone company service that goes in
your company. If you dial a “9” to get an outside line, then
you have a PBX.
The “Cloud”—This is where all WAN starts and ends. We
use this in many instances…to represent the Internet, a
frame relay cloud, an ISDN cloud, a POTS cloud, etc.
PC/Workstation—I really should not have to explain this
one.
Dumb terminal—Like a regular PC, but no hard disk. It
was mainly used to connect to mainframe who did the
storage and processing for them.
Printer—I really should not have to explain this one either.
So there.
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