Auto-Negotiation; Parallel Detection; Full Duplex Network; Half Duplex Network (512-Bit Rule) - Transition Networks CBFTF1011-155 User Manual

CBFTF10xx-15x
Operation
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Product Features
AutoCross™
The AutoCross feature detects and configures the twisted-pair copper port on the
CBFTF10xx-15x media converter to the correct straight-through (MDI) or
crossover (MDI-X) configuration. This feature allows either MDI or MDI-X cable
to connect the media converter to devices such as hubs, transceivers, or network
interface cards (NICs). (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, which, in turn, disables the link on the
copper portion of the network (3) and (4).
on the fiber link
Near-End Media
Device Converter A
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media converter A
disables the copper link

Auto-Negotiation

The Auto-Negotiation feature allows the CBFTF10xx-15x media converter to
automatically configure itself to achieve the best possible mode of operation over a
link. The media converter will broadcast 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.
100 Mb/s, half duplex). Disabling this feature gives the user the ability to force the
connection to the best mode of operation.

Parallel detection

Parallel detection is the method used to link when an auto negotiating port detects a
link partner that is in forced mode and therefore cannot participate in the auto
negotiating process. Parallel Detection can be set to IEEE Standard half duplex, or
the non-standard full duplex. Switch settings for parallel detection are valid in
hardware or software mode, only when Auto-Negotiation is enabled.
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original fault
1
Media
Converter B
2
3
Far-End Fault media converter B
signal is sent disables the copper link
Operation
Product Features - Continued
Parallel detection --continued
Per the IEEE method, an auto negotiating port that detects a forced link partner
should drop to the detected speed (10Mbs or 100Mbs) and default to half duplex
The CBFTF-155 allows bypassing the IEEE method by setting the parallel detection
default mode to half or full duplex via DIP switch 3.

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 CBFTF10xx-15x models.

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
Far-End
the round-trip delay in bit-times (BT) of a particular collision domain. If the result
Device
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-line at: www.transition.com.
SNMP
See the on-line documentation that comes with Transition Networks FocalPoint™
software for applicable commands and usage.
Use SNMP at an attached terminal or at a remote location to monitor the media
converter by monitoring:
•
•
•
•
•
•
•
Also, use SNMP to enter network commands that do the following:
•
•
•
•
•
techsupport@transition.com -- Click the "Transition Now" link for a live Web chat.
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Media converter power
Serial and port number
Chassis slot position
Copper and fiber link status
Copper and fiber duplex mode
Copper port speed
Hardware switch setting
Enable/disable Auto-Negotiation on copper
Force 10Mb/s or 100Mb/s on copper
Force full duplex or half duplex on copper
Force full duplex or half duplex on fiber
Enable/disable Far-End Fault on fiber
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