Hi Nitin,
E1 means the European standard of Primary Carrier Multiplex (PCM), T1 (American) and J1 (Japanese). E1 has 32 timeslots (TS) out of which 2 TS carry Signalling and Sync. Each Channel carries 64kbps of Pulse Code Modulated (PCM) voice.
TAX (Trunk Automatic eXchange) is a higher hierarchy of the switch, which usually carries STD calls from one region to other.
And Now E1 for TAX is the E1 PCM which is connected directly to TAX, and E1 local is …
Hope this helps….