The Adtran SDX 6XXX Combo OLT 4-Port optical line terminal (119713SW04F3, Millennium part #544571) is a base software license enabling four-port GPON/combo PON service on Adtran's SDX 6000 series platform. This central office electronics component activates OLT capacity for delivering fiber-to-the-home and business services over Adtran's converged access infrastructure, giving service providers a scalable path to grow subscriber counts without replacing hardware. Millennium supplies this Adtran OLT software alongside compatible SDX chassis, ONTs, and SFP optics for complete network builds. Contact Millennium's team to confirm compatibility with your existing SDX deployment and to get current pricing.