The Flexi mux is a programmable Add/Drop multiplexing equipment
It combines voice and data traffic into a 2.048 Mbps stream.
This equipment is manufactured and supplied by Webfil Limited.
The Add/Drop feature of the Flexi mux is realized through the use of a high performance time/space non-blocking cross-connect switch
It has four independently controlled serial time division multiplexed buses.
Conferencing of voice is done through a separate digital signal processing circuit in digital format.
All the signaling information is handled by a microcontroller.
Digital Conference is done on any three voice slots in a separate digital signal processor.
Conference can be three way (full conference) or two and half way(semi-conference) as required by the user.

Network Interface Module (NIM)
- The Network Interface Module primarily takes care of alarm acquisition function
- It collects alarms from various internal and external sources and responds to the queries and commands issued by the Network Manager through the ―Super Net‖ Network Management System
- The Network Interface module is used for exchange of information among the Network Manager, the Tributary Module and the various access modules interconnected via the back plane.
- It has altogether four communication interfaces for information exchange.
- The network management system is realized through two serial interfaces, one for external NMS for interfacing the central supervisory computer while the other is used for realizing the NMS through the unused National bits of the 2 MB stream.