Media Converter for Ethernet OAM

LEX3851-1F is the world’s smallest*1 Ethernet OAM compatible 10/100/1000BASE-T to 100BASE-FX/1000BASE-X (SFP) media converter.

  • Is the world’s smallest Ethernet OAM compatible Giga media converter.
  • The optical module utilizes SFP and supports 100BASE-FX, 1000BASE-SX, SX2, LX and ZX. It can also be used with single fiber type (BiDi/BX) or CWDM SFP.
  • Switch operated and jumbo frame compatible.
  • LED-verifiable signal detection function.
  • Instant power-off notification function (Dying Gasp).
  • Fanless design. Made in Japan – Japanese quality.

*1 Among stand-alone Ethernet OAM compatible Giga media converters,
according to FXC’s findings as of April 18, 2018.




  • LEX3851-1F


  • A media converter capable of converting 10BASE-T, 100BASE-T and 1000BASE-T ports into 100BASE-FX and 1000 BASE-SX/SX2/LX/ZX ports.
  • Can be built into a chassis or used as a stand-alone device. *Chassis will be released at the beginning of July 2018.
  • Includes Ethernet OAM function (continuity check by Ethernet frame transmission and reception).
    -IEEE 802.3ah (adjacent node: Link DAM): Discovery, Link Monitor, RFI, Dying Gasp
    -IEEE 802.1ag (non-adjacent node: CFM OAM): Continuity Check, Loop Back and Link Trace compliance scheduled for July 2018
    -ITU-T Y.1731 (non-adjacent node expansion: CFM OAM): AIS, RDI, DM, LM and TST compliance scheduled for July 2018
  • Various settings are available in stand-alone format (Link OAM, LFP (link fault pass through), flooding mode, Optical Automatic Negotiation on/off)
  • Link state, setting source and F/W update indicated by LEDs.
  • Supports jumbo frames (10000 Bytes).
  • Supports BPDU and EAPOL transmission.
  • Hot swap compatible when built into a chassis. *Chassis will be released in July 2018.
  • Supplied with various attachment accessories (magnets, rubber lugs, retaining bands)

Network configuration example

Network configuration example


Models LEX3851-1F
Standards IEEE802.3, IEEE802.3u, IEEE802.3ab, IEEE802.3z, IEEE802.3h
Transmission speed 10/100/1000Mbps(CSMA/CD)
UTP ports 10BASE-T/100BASE-TX/1000BASE-T 1port(MDI/MDI-X auto switch)
Auto Negotiation Supported
Fiber ports Number of SFP ports 1port
Optical input / output Specification SFP specification、100BASE-FX/1000BASE-X Automatic switching
Auto Negotiation Enable / disable setting、FEF
Copper cable 10BASE-T UTP Cat.3
100BASE-TX UTP Cat.5
1000BASE-T UTP Cat.5e
1000BASE-SX/SX2 MMF 62.5/125μm or 50/125μm
1000BASE-LX/ZX SMF 9/125μm or 10/125μm
Transmission mode Switching mode
Maximum frame size 10,000byte
MAC address 8,192
Communication function link fault pass through(Default:OFF)
EAP/BPDU transparent.
Ethernet OAM(IEEE802.3ah) (Default:OFF)
Flow Control Half-duplex: Back Pressure, Full-duplex:IEEE 802.3x
Latency 1.9μs
Rated input voltage/frequency AC power AC90~240V
Maximum input current 2A
Maximum calorific value 3.44kcal/h
Cooling system natural cooling (fan-less) natural cooling(fan-less)
User Environmental Operating
(no condensation)
Dimensions 55mm(W)x110mm(D)x20mm(H)
without detachable parts
Physical specification 160g (without AC adapter and Optional Accessories)
VCCI class A
ISO Environmental
Reliability MTBF:306,000h
(25℃, without SFP)
Accessories AC adapter supports PSE、
magnet, rubber foot covers、
installation guide product warranty、
Adapter cable falling prevention banding band

Page Top