Wires and Wireless Flashcards
802.11a
5 GHz
54 Mbps
120m
802.11b
2.4 GHz
11 Mbps
140m
802.11g
2.4 GHz
54 Mbps
140m
Backwards compatable w/ 802.11b
802.11n
5 GHz & 2.4GHz
600 Mbps
250m
WEP
64-bit or 128-bit key size
Cryptographic vulnerabilities
WEP can no longer be used
WPA
Short-term workaround after WEP
Used RC4 cipher as TKIP (Temporal Key Integrity Protocol)
TKIP has its own vulnerabilities
WPA2
Replaced TKIP with CCMP (Counter Mode with Cipher Block Chaining Message Authentication Code Protocol)
Replaced RC4 with AES (Advanced Encryption Standard)
Latest and most secure wireless encryption method
WPA2 Enterprise
Adds 802.1x
RADIUS server authentication
Two types of Optical Fiber
Multimode: Short-range communication (2km)
Single-mode: Long-range communication (100km)
Media Converters
OSI Layer 1
Copper to fiber, fiber to copper
Fiber conversion - single-mode to multimode
Connectors: ST, SC, LC, MT-RJ
CAT 3
10Base-T
10 Mbps
100m
RJ-11
CAT 5
100Base-TX
100 Mbps
100m
RJ-45
CAT 5e
1000Base-T
1000 Mbps
100m
RJ-45
CAT 6
1000Base-T/10GBase-T 1000 Mbps = 100m - or - 10 Gbps = 55m RJ-45
Coaxial Cable Composition
(outside - in) Plastic Jacket Metal Shielding Dielectric Insulator Wire Conductor
UTP/STP
Unshielded/Shielded Twisted Pair
Plenup rated = fire-resistant cable jacket
Coaxial Cable
Older Ethernet networks (RG-8/U)
Broadband Internet (RG-56)
Short-distance video (RG59)
Straight Through Cable
Connects unlike devices
Same on both ends
T1 Crossover Cable
Connects like devices
1————–4
2————-5
4————–1
5————-2
568 A/B Crossover
Connects like devices
1----------3 2---------6 3---------1 4---------4 5---------5 6---------2 7---------7 8--------8
568 A
WG | G | WO | BL | BLW | O | WB | B
568 B
WO | O | WG | BL | BLW | G | WB | B
CAT 6a
10GBase-T
10 Gbps
100m
RJ-45
Decibles (dB)
A logarithmic scale
- 3 dB = 2x the signal
- 10 dB = 10x the signal
- 20 dB = 100x the signal
- 30 dB = 1000x the signal
Calculating dB Loss
(through 1km of fiber)
Add loss through each section * 1 km fiber = 3.5 dB * Patch panel at each end = .5 dB (x2 patch panels) = 1 dB Total link loss = 4.5 dB
T1
24 channels
64 kbps/channel
1.544 Mbps/line rate
E1
32 channels
64 kbps/channel
2.048 Mbps/line rate
T3
28 - T1 circuits
672 T1 channels
44.736 Mbps
E3
16 - E1 circuits
512 E1 channels
33.368 Mbps
10 Mbps Ethernet
10Base-T - Twisted Pair
100 Mbps Ethernet
100Base-TX - CAT 5 twisted pair, 100m
100Base-FX - MMF (2km), SMF (2km+)
1000 Mbps Ethernet
1000Base-T - CAT5e or CAT 6, uses all pairs, 100m
1000Base-LX - LW fiber, over 5km
1000Base-SX - SW fiber, 550m
10 Gbps Ethernet
10GBase-SR (short range) - MMF, 300m 10GBase-LR (long range) - SMF, 10km-25km 10GBase-ER (extended range) - SMF, 40km 10GBase-SW , 10GBase-LW, 10GBase-EW - 10G over SONET and SDH 10GBase-T - CAT 6 (55m), CAT 6a (100m)
Satellite Networking
15 Mbps down/2 Mbps up High latency High Frequencies (line of sight, rain fade)
ISDN
Integrated Services Digital Network
Two Types:
1) BRI (2B+D):
* 2-64k Bearer Channels (B)
* 1-16k Signaling Channel (D)
2) PRI (23B+D):
* T1 - 23B+D
* E1 - 30B+D+alarm channel
DSL
Digital Subscriber Line
1) ADSL (Asymmetric DSL):
* 24 Mbps down/3.5 Mbps Up
2) SDSL (Symmetric DSL):
* Never Standardized
3) VDSL (Very high bitrate DSL)
* 4 Mbps to 100 Mbps
Cable Modem
DOCSIS (Data Over Cable Service Interface Specification)
4 Mbps-100 Mbps
Dialup
Legacy System
56k
CSU/DSU
Channel Service Unit/Data Service Unit
Connects WAN to DTE
Rollover Cable
Administrative console
1------------8 2-----------7 3-----------6 4-----------5 5-----------4 6-----------3 7-----------2 8-----------1
Router
Multiple Broadcast Domains
Layer 2 Switch
Single Broadcast Domain
Multiple Collision Domains
Wireless AP
Single Broadcast Domain
Single Broadcast Domain
Hub
Single Broadcast Domain
Single Collision Domain