Transition Networks SBFTF10XX-15X - Manual (Page 4)

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SBFTF10xx-15x
24-Hour Technical Support: 1-800-260-1312 -- International: 00-1-952-941-7600
Operation
- Continued
Product Features
Auto-Negotiation
The Auto-Negotiation feature allows the media converter to automatically
configure itself to achieve the best possible mode of operation over a link.
The media converter broadcasts its speed (10 Mb/s or 100 Mb/s) and duplex
capabilities (full or half) to the other devices and negotiates the best mode of
operation. Auto-Negotiation allows quick and easy installation because the
optimal link is established automatically. No user intervention is required to
determine the best mode of operation.
A scenario where the media converter is linked to a non-negotiating device is
a case where the user may want to disable Auto-Negotiation. In this instance,
the mode of operation will drop to the least common denominator between
the two devices (e.g. 10 Mb/s, half-duplex). Disabling this feature gives the
user the ability to force the connection to the desired speed and duplex mode
of operation.
AutoCross™
When the AutoCross feature is activated, it allows either straight-through
(MDI) or crossover (MDI-X) copper cables to be used when connecting to
10Base-T or 100Base-TX devices. AutoCross determines the characteristics of
the connection and automatically configures the unit to link up, regardless if
the copper cable is MDI or MDI-X configuration. (This feature does not
require operator intervention.)
Far-End Fault
When a fault occurs on an incoming fiber link (1), the media converter
transmits a Far-End Fault signal on the outgoing fiber link (2). In addition the
Far-End Fault signal also activates the Link Pass-Through feature, which, in
turn, disables the link on the copper portion of the network (3) and (4).
Far-End Fault
signal is sent
Media
Converter A
Media
Converter B
Near-End
Device
Far-End
Device
original fault
on the fiber link
media converter B
disables the copper link
media converter A
disables the copper link
3 4 2
1
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Operation
- Continued
Product Features - Continued
Full-Duplex Network
In a full-duplex network, maximum cable lengths are determined by the type
of cables that are used. See page 1 (front cover) for the cable specifications
for the different SBFTF10xx-15x models.
The 512-Bit Rule does not apply in a full-duplex network.
Half-Duplex Network (512-Bit Rule)
In a half-duplex network, the maximum cable lengths are determined by the
round trip delay limitations of each Fast Ethernet collision domain. (A
collision domain is the longest path between any two terminal devices, e.g. a
terminal, switch, or router.)
The 512-Bit Rule determines the maximum length of cable permitted by
calculating the round-trip delay in bit-times (BT) of a particular collision
domain. If the result is less than or equal to 512 BT, the path is good.
For more information on the 512-Bit Rule, see the white paper titled “Collision
Domains” on the Transition Networks website at: www.transition.com.
Cable Specifications
Copper Cable Maximum cable distance: 100 meters
Category 3: (minimum requirement for 10 Mb/s operation)
Gauge
24 to 22 AWG
Attenuation 11.5 dB/100m @ 5-10 MHz
Category 5: (minimum requirement for 100 Mb/s operation)
Gauge
24 to 22 AWG
Attenuation 22.0 dB /100m @ 100 MHz
• Straight-through(MDI) or crossover (MDI-X) cable may be used.
• Shielded (STP) or unshielded twisted-pair (UTP) may be used.
• Pins 1&2 and 3&6 are the two active pairs in an Ethernet network .
• Use only dedicated wire pairs for the active pins:
(e.g., blue/white & white/blue, orange/white & white/orange, etc.)
• Do not use flat or silver satin wire.
Crossover Cable
1
2
3
6
Straight-Through Cable
Twisted Pair #1 Twisted Pair #1
Twisted Pair #2 Twisted Pair #2
1
2
3
6
1
2
3
6
1
2
3
6