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CSRFB10xx-100
24-hour Technical Support: 1-200-260-1312 -- International: 00-1-952-941-7600
Far-End
Device
Near-End
Device
Media
Converter A
Media
Converter B
2
Original fault on
fiber link
Converter B
disables copper lin
k
Far-end fault
signal sent
3
4
1
Converter A
disables copper link

Auto-Negotiation

The Auto-Negotiation feature allows the CSRFB10xx-100 media converter to
automatically configure itself to achieve the best possible mode of operation over a
link. The media converter will broadcast its speed (10Mbps or 100Mbps) and
duplex capabilities (full or half) to the other converters 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 converter 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
converters (e.g. 100 Mbps, half duplex). Disabling this feature gives the user the
ability to force the connection to the best mode of operation.
Operation -- Continued

Product features -- continued

Transparent link pass-through (TLPT)

TLPT notifies the end converter of a link failure by sending a link-loss signal over
the fiber, instructing the terminal converter to shut down the copper port thus
notifying the end converter. The fiber link between the two converters will be
maintained.
• End converter automatically notified of link loss
• Fiber link remains up as it carries the link-loss signal

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).
Far-End
Device
Near-End
Device
Media
Converter A
Media
Converter B
Converter A loses
copper RX link
with end device
2
Converter A
sends a link loss
signal over the
fiber
End device is
notified of link
loss
Converter B
receives link loss
signal and disables
the copper TX port
3
4
1
techsupport@transition.com -- Click the “Transition Now” link for a live Web chat. 9
Operation -- Continued
Product features - continued

Parallel detection

Per the IEEE method, an auto-negotiating port that detects a forced link partner
should drop to the detected speed (10Mbps or 100Mbps) and default to HALF
DUPLEX.

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 CSRFB10xx-100 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 converters, 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-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:
• Media converter power
• Serial and part number
• Port number
• Copper and fiber link status
• Copper and fiber duplex mode
• Copper port speed
• Hardware switch setting
• View terminal converter status
• Set port ingress rate limits of the center side converter
Also, use SNMP to enter network commands that do the following:
• Enable/disable Auto-Negotiation on copper
• Force 10Mbps or 100Mbps on copper
• Force full duplex or half duplex on copper
• Force full duplex or half duplex on fiber
• Enable/disable Transparent Link Pass Through