Lesson 5: Modern Ethernet

100BaseTx (100 BaseT)

speed: 100 Mbps

signal type: Baseband

distance: 100 meters

node: upto 1024 per hub

topology: star-bus

cable: CAT5e or better UTP or STP RJ-45 connectors

A. if you have 10BaseT and need an upgrade

• need NIC with 100BaseT
• CAT5 cable
• switch w/ 100BaseT NICs

B. multispeed auto-sensing 100BaseT

• have auto-negociation for 10BaseT and 100 capability
• techs call it a 10/100 NIC
• all modern NICs are 10/100, auto-sensing

100BaseFx

speed: 100 Mbps

signal type: Baseband

distance: 2 km (remember the old 10BaseF has 2000 m)
node: upto 1024 per hub

topology: star-bus

cable: multimode fiber optic, ST or SC

I. Full-Duplex Ethernet

• doesnt increase network speed, but double the bandwidth
• disables CSMA/CD — elimiates collisions

II. Gigabit Ethernet

• IEEE 802.3ab standard — 1000BaseT with 4 pair UTP, STP
• IEEE 802.z standar — 1000BaseX
• 1000BaseX has three types: 1000BaseCx, 1000BaseSx, 1000BaseLx

A. 1000BaseCx

• has unique cable, twinaxial cable or “twinax”
• special shield 150-Ohm cables, length limit 25 meters
• not popular

B. 1000BaseSx

• multimode fiber optic cables
• 220–500 meters
• 850nm wavelength LED
• looks similar to 100BaseFx but 1000BaseSx uses LC while 100BaseFx uses SC

C. 1000BaseLx

• long distance carrier gigabit ethernet
• single mode, laser cables
• 5 kilometers, some even 70 kilometers
• looks like Sx connectors

III. New Fiber Connectors

• problems with ST and SC connectors
• ST is large, has twist-on
• small form factor (SFF) connectors are used
• mechanical transfer registered jack (MT-RJ) is popular with Cisco, common
• local connector (LC), is popular in the US, also the most popular fiber connector
• gigabit interface convertor (GBIC) is the standard for modular ports

IV. 10 Gigabit Ethernet ( 10 GbE)

• new technology designed for fiber and 2 copper standard

A. Fiber-based 10GbE

i. challenges:

* maintain integrity of the Ethernet frame

* how to transfer frames at blazing speeds

ii. standards for WAN, SONET infrastructure over WAN fiber and also traditional WAN physical layer

iii. 10GbE standards defined by:

1. type of fiber

2. wavelength of laser/lasers

3. physical layer signaling type

• The format of the 10 GbE looks like this:
• 10GBasexy:
• x is for the type of fiber
• y is for the physical layer signaling type
• “R” for LAN-based signal or
• “W” for SONET/WAN signal
  ex: 10GbaseSy — uses short-lengh (850 nm) over MMF with max length of 300 meters

1. 10GBaseS”y” Types

• 10GBaseSR or 10GbaseSW
• 850nm wavelength
• 25–300 meters distance

2. 10GBaseL”y” Types

• 10GBaseLR or 10GBaseLW
• longwave, 1310 nm
• signal SMF
• 10 km distance

3. 10GbaseE”y” Types

• extra long wavelength 1550 nm
• SMF
• max length is 40 km distance

Other Types not in CompNet+

• 10GBaseL4, 10GBaseLRM, 10GBaseZR

B. Copper-based 10GbE

• 10GBaseT, on CAT6 the max length is 55 meters, on the CAT6a the max length is 100 meters
• 10GbE physical connections — all 10GbE send and receive the same signal, only the physical medium is different
• multisource agreements (MSAs) allow you to convert one media type to another by inserting the right transreceiver
• ex: XENPAX MSA

C. Backbones:

• multispeed Ethernet network
• switches maintian a backbone netowrk
• servers connect to the backbone
• need switches with separate dedicated high-speed ports

. READING NOTES

Review of all cable types: