Cisco 4400 Series Integrated Services Router 1-, 2 , and 4-Port Serial Network Interface Modules Cisco® 4400 Series Integrated Services Router Network Interface Modules (ISRNIMs) provide highly reliable synchronous serial WAN connections for remote sites. These interfaces use well-known point-to-point WAN protocols such as High-Level Data Link Control (HDLC) and Point-to-Point Protocol (PPP) as well as Frame Relay, offering cost-effective virtualized WAN connections in both point-to-point and point-to-multipoint designs. You can mix and match NIMs to tailor cost-effective solutions for common networking solutions for low- and high-density WAN aggregation. Cisco offers three new synchronous serial NIMs: ● Cisco 1-Port Serial WAN Network Interface Card (NIM-1T) ● Cisco 2-Port Serial WAN Network Interface Card (NIM-2T) ● Cisco 4-Port Serial WAN Network Interface Card (NIM-4T) The NIM-1T, NIM-2T, and NIM-4T use Cisco Smart Serial connectors. These ports use the same connectors and cabling as the HWIC-4A/S and HWIC-2A/S modules for the Cisco Integrated Services Routers Generation 2 (ISRG2) routers.