Cisco ISR 4321 (2GE,2NIM,4G FLASH,4G DRAM,IPB)

“2-Port Serial WAN Interface Card” is a network interface card (NIC) that provides two serial ports for connecting to wide area network (WAN) communication links. This interface card is commonly used in networking equipment, such as routers, to enable connectivity to remote sites or devices over serial connections.This type of interface card offers two serial ports. Each port can be used to establish a point-to-point serial connection to another device, such as another router, modem, or terminal server.Serial connections which is for data communication over relatively longer distances. They use serial transmission protocols to send and receive data bit by bit, making them suitable for connections over leased lines, dial-up connections, and other WAN links. Serial connections that can also be used for various WAN connectivity scenarios, including connecting remote offices, branch locations, or equipment in industrial settings.