Spartan Labs 2 of 3
ISDN B-channel Monitoring Application
Genesis
Our customer, a world number 2 in telecom test and measurement instrument was going through
rough patch due telecom meltdown. Their product design center in France was consolidated.
During this time they got a big order from a European telco for an ISDN BRA/PRA test
instrument, a product that was conceived, designed and maintained by France design center. The
only hitch was the order required a B channel monitoring application on the instrument. With all
the expertise gone during meltdown, our customer was facing a challenge to build this application
to comply to terms of the order.
Spartan Labs made a proposal to take over the source repository, to study the source code,
document the existing design and then design the new B-channel monitoring application. It was
tough for our customer to believe that such a complicated product can be understood from the
source repository but after our assurances they took the chance and trusted us with project.
Project
ISDN BRA/PRA tester is a handheld instrument based on Motorola
PowerPC and VxWorks. Our team took charge of CVS source repository, studied it in detail for 8
weeks, drew the architecture and documented the design of the existing product. They validated
the understanding of design by carrying out certain tests on several existing applications.
Once the existing monster was understood, they went about designing a B channel monitoring
application. It required, capturing of frames from the E1 interface chip, filtering them to pick up B
Channel frames then providing detailed decode of PPP/MLP (Point to Point and Multilink protocol)
frames. A decode engine was developed to decode a number of and GUI was developed in Zinc to
allow user to view the decodes. Online as well as offline decoding was enabled. Besides this
following features were developed in application:
· Trigger,
· Storing decodes in a file
· Hex dump of the frames
· Internationalization: support for German, French and Spanish
· Third party PC based Decoder support
· Online Help
· Offline Filters
· Replay of captured frames
So impressed was our customer, we were entrusted with sustenance contract for the device
completely for 1 and half year. As part of the sustenance, we added several features,
supplementary services, fixed bugs, carried out enhancements and made regular maintenance
releases. We developed a full-fledged telecom test lab with Alcatel OmniPCX exchange to meet
the testing requirements.
