SONET & SDH optical testing

OC-3/STM-1 and OC-12/STM-4 Analysis and Emulation

SonetExpert™ BERT Testing over SONET/SDH

Web-based Bit Error Rate Testing over SONET/SDH OC-3 / STM-1, OC-12 / STM-4, OC-48/STM-16 and OC-192/STM-64 rates.



SonetExpert™ BERT is a web-based application which supports Bit Error Rate Testing over SONET/SDH OC-3 / STM-1, OC-12 / STM-4, OC-48/STM-16 and OC-192/STM-64 rates. using GL's versatile multifunctional Ethernet/SONET hardware test platform – SonetExpert. Supports BER Traffic generation and verification of various PRBS and user defined test patterns. Various Error insertions like, Bit Error Insertion, B1/B2/B3 BIP Error insertion, Alarm generation etc

Hardware supports two ports. Full line rate BER traffic generation and analysis for all the supported rates is possible on both ports simultaneously. Hardware is USB based and interfaces with a host PC through a USB 3.0 interface. Multiple hardware units can be connected to a single PC to increase test port density.

GL also offers High-Density mTOP™ 1U/2U rack mount enclosures within which multiple SonetExpert™ hardware units are stacked to provide high density form factor solution for testing multiple SONET/SDH lines. It is a perfect SONET/SDH test tool for customers who require multi-port testing but are constrained by lab space

GL also offers stand-alone mTOP™ Probe hardware variant of SonetExpert, where a SonetExpert™ hardware unit is coupled with a built in SBC (Single Board Computer), to make it a compact, portable toll, ideal for field testing.

Software is provided in the form of an easy to use and intuitive web interface. All the functionalities can be accessed from any standard web browser. This makes it convenient to control the hardware from multiple locations and from multiple access devices like a PC, laptop and even a tablet. Also, the client machine can be any OS like Windows/Linux/Android etc. as long as web browser can run on it

Main Features

  • Supports Bit Error Rate Testing over SONET/SDH OC-3 / STM-1, OC-12 / STM-4, OC-48/STM-16 and OC-192/STM-64 rates
  • Software selectable OC-3 / STM-1, OC-12 / STM-4, OC-48/STM-16 and OC-192/STM-64 rates
  • Wire-speed BERT on two ports simultaneously
  • Supports industry standards PRBS patterns 29-1, 211-1, 215-1, 220-1, 223-1, 229-1, and 231-1, all one's, all zero's, alternate ones and zeros, and 4 byte 32 bits user-defined test patterns. Also supports Pattern inversion
  • Provides various SONET Alarms like LOS, LOF, OOF, B1/B2/B3 Alarms, as well as BERT alarms like Sync Loss and Bit Error Alarms
  • Impairments :
    • Set SONET Pointer and Justification(both Positive and Negative justification)
    • LOF (Loss of Frame) Alarm Generation.
    • B1, B2, B3 BIP Error Insertion (Single as well as rate error insertion)
    • Bit Error Insertion (Single as well as constant rate Bit Error insertion)
  • Software provided as a web interface, accessed from any standard web browser, allowing access from different devices like Pcs/laptops/tablets etc. and also from different OS like Windows/Linux/Android etc.
  • Web interface allows multiple users to connect to a single web server and independently run tests on different hardware units
  • Portable and high port density form factors for all kinds of testing needs


GL’s SonetExpert™ BERT provides two types of Alarms – SONET Alarms and BERT Alarms.

  • SONET Alarms supported:
    • LOS (Loss of Signals)
    • OOF (Out of Frame)
    • LOF (Loss of Frame)
    • B1/B2/B3 BIP Bipolar Alarms
    • All Ones Alarm
    • OC Levels Alarm
    • Unequipped Alarm
    • PLM (Payload Label Mismatch) Alarm
  • BERT Alarms supported:
    • Bit Error Alarm
    • Sync Loss Alarm

For each alarm, the status, seconds, and count is displayed. Both current as well as history status is displayed in the form of a LED for quick attention.


Clock Source Selection


SonetExpert™ provides various options to select the clock source:

Internal – clock source is Internal clock present on the hardware

Recovered – clock is recovered from incoming signal of the same port

Recovered (Opposite Port) – clock is recovered from incoming signal of the other port

External – user can connect an external clock source

BER Analysis

BER analysis reports the Pattern Sync Status, the Bit Error count, Bit Error Rate etc


Error Insertion


SonetExpert™ provides 2 types of Error Insertion –Bit Error Insertion and BIP Error Insertion. Bit Error insertion allows inserting Bit Errors into the outgoing Tx traffic. Bipolar Error insertion allows sending packets with wrong B1, B2 and B3 value.

In both the Bit Error and BIP Error Insertion types, single as well as Rate Error Insertion is supported. Single error insertion allows user to manually introduce a single Bit/BIP error. Rate Error insertion allows the user to select a constant error rate, ranging from 10^-3 to 10^-9, to be introduced into the outgoing stream.

Also, User can set the H1/H2 Pointer value, as well as introduce negative and positive justification into the outgoing stream. Both Single as well as rate justification can be introduced


The Bit Errors and Sync Status are continuously plotted and displayed in an Event Graph as shown below:



Item No Item Description
SEU901 SonetExpert™ UnChannelized BERT for OC3/STM1 and OC12/STM4 Rates
SEU902 SonetExpert™ UnChannelized BERT for OC3/STM1, OC12/STM4 Rates, OC48/STM16, OC192/STM64 Rates
SEUE02 SonetExpert™ Channelized Analyzer (OC-3/STM-1)
SEUT02 SonetExpert™ Channelized Analyzer (OC-12/STM-4)
SEE001 SonetExpert™ OC-3/STM-1 Basic E1 Software
SET001 SonetExpert™ OC-3/STM-1 Basic T1 Software
Optional Applications
SEU110 SonetExpert™ Upgrade to PXN100
SEU120 SonetExpert™ Upgrade to PXN101
PXN100 PacketExpert™ 10GX
PXN101 10G option for PXN100