The DPT port adapter is a dual-width OC-12c port adapter that provides a shared IP over SONET capability in a Cisco 7200 series router, Cisco uBR7246 router, Cisco 7200 VXR router, or Cisco 7500 series router with VIP4 or later. The DPT port adapter provides Cisco 7200 series, Cisco uBR7246, Cisco 7200 VXR routers, or Cisco 7500 series routers with two SC duplex ports. Each SC duplex port provides the physical connection to an adjacent device in a DPT ring. The DPT port adapter is designed to be deployed in SONET OC-12c DPT rings. DPT rings can also be connected to SONET Add Drop Multiplexers (ADMs), thus allowing for the creation of small or very large DPT rings.