PA-2JT2 is a port adapter used on the VIP2 in the Cisco 7500 series routers, and in Cisco 7000 series routers using the RSP7000 and RSP7000CI. Each JT2 interface port consists of two coaxial, BNC connectors. It provides two data terminal equipment (DTE), synchronous serial interface ports, which are compatible with and specified by G.703a, and which permit Cisco 7000 series and Cisco 7500 series routers to communicate over a High Speed Digital 6.3 MHz (HSD 6.3) leased line service (specified in ITU Recommendation G.704).At a minimum, you must use the VIP2-40 (with 2 MB of SRAM and 32 MB of DRAM) or VIP2-50 (with 4 to 8 MB of SRAM and 32 to 128 MB of SDRAM) for use with one or two JT2 port adapters. Cisco does not recommend the use of any other VIP2 model with PA-2JT2.