My shopping cart My cart:
skip to the main content area of this page

LB-100 (10/100 Base-T)

      2 UTP Ports Ethernet Loopback Device


In general, to perform a loopback test requires two test ports on both packet generator and DUT/NUT for transmission and receiving of test packets. It may not be available to do the loopback test in real network environment if the network under test is located far away from the packet generator with only one linked network cable.

Utilize one network cable to fulfill the loopback test is the best way in real network environment. To achieve the goal, loopback device LB-100 is just suitable for this test. LB-100 filters broadcast, multicast packets and resends the rest of test packets to the same network cable by two selective methods; resends directly (layer 1 loopback) or resends with swapped DA/SA (destination / source MAC address) and recalculated CRC for different applications (layer 2 loopback).

Packet generator such as NuDOG of Xtramus can generate and receive Throughput, Latency or Loopback test patterns for analysis via one network cable. For this application, the loopback device, LB-100 is connected at remote location to resend the loopback or others test patterns. By this way, extra network cable is not required for the test.

Easy and distinctive real-time LED indicators for network speed, duplex mode, loopback mode, packet length, common errors, utilization and elapsed test time in LED digits display make LB-100 not just a loopback device, but also a full functional link tester.

LB-200 test 1

System features

  • Two selective Loopback modes. Layer 1 loopback and Layer 2 loopback for two individual port.
  • Perform round-trip Throughput and Latency test by NuDOG with NuDOG-2544 application software.
  • Handheld device that is portable to any test site.
  • Elapsed Time shown on LED digits display in order to know the duration of a single test.
  • Two network ports for 2 sets of individual loopback test simultaneously. Convenient hotkey to switch the loopback mode for different port (A or B) in the test.
  • Distinctive LED indicator that is able to pinpoint the status of current running network.
  • Clear the status LED by hotkey any time for next loopback test. Status is kept unless clear hotkey is pressed.
  • Real-time LED indicator of network speed, duplex mode, loopback / PG mode, packet length, common errors (CRC, Loss), utilization and elapsed test time in LED digit display.


  • Work with packet generator such as NuGOG of Xtramus for loopback test
  • Perform network Throughput and Latency test by NuDOG with NuDOG-2544 software application tool.
  • Detect network link status for troubleshooting / debugging purpose after wiring of network cable.
  • Monitor network utilization by real-time LED indicator

Return to All Items