supply of master telephone/slave telephonemaster telephone/slave telephone,supply , transportation, installation, testing and commissioning of master telephone with inb uilt voice logger along with power supply as per spec no- rdso/spn/tc-51/11 rev. 3.0 or latest and compa tible with existing lc gate communication system. make/brand: -bentron or similar. [ warranty period: 3 0 months after the date of delivery ] ] , supply and transportation of slave telephone suitable for ofc based gate communication fol lowing rdso spec. no. rdso/spn/tc/51/2021 rev. 1. make/brand- bentron or similar. [ warranty period: 30 months after the date of delivery ] ] , supply, installation, testing and commissioning of slave telephone as per spec no- rdso/sp n/tc51/11 rev. 3.0 or latest and compatible with existing lc gate communication system. make/brand: - b entron/epsilon or similar. [ warranty period: 30 months after the date of delivery ] ] , supply and transportation of ofc based master telephone unit for 6 code gate communicatio n with voice recording facility complying to latest rdso spec. no. rdso/spn/tc/51/2021 rev. 1. make/bran d- bentron or similar. [ warranty period: 30 months after the date of delivery ] ] , supply and transportation of ofc based master telephone unit for 6 code gate communicatio n with voice recording facility complying to latest rdso spec. no. rdso/spn/tc/51/2021 rev. 1. make/bran d- bentron or similar. [ warranty period: 30 months after the date of delivery ] ]