tender for supply, installation, testing and commissioning of new ip based epabx (including telephone handsets) at gail hcs on buy-back basis with 02 years on-site warranty and 05 years on site post-warranty comprehensive amc.; 1 sitc of ip based epabx system 2 sitc of ip based epabx system at gail hazira with 2 years on-site warrantyof completesupplied ip based epabx system(including all associated system analog telephone ,digital telephone, ip phone, modules etc) this includes following(but not limited to)design, supply, installation,testing & commissioning of ip based epabx system (on buy back basis) with uc facilities scalabe upto 5000 users (analog, digital, ip/sip, pri, sip trunks, co lines etc.),built around server platform hot s/by config for its critical common and control units and resource elements natively serving ipsubscribers and runks and also serving tdm subcribers and trunks through (please refer scc,scope of work & technical specifiction) 3 post warranty comprehesive amc 4 comprehensive amc of 5 years of complete ip based epabx system(including all associated system analog telephone ,digital telephone, modules etc)at gail hazira :24x7 on-line support (with quaterly pm visit); please refer the detailed scc & sow as described in the tender document. 5 buy back items 6 buy back of unify make openscpae-4000 epabx system at gail hazira