SBFTF10xx-15x
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).
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-15xmodels.
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 |