https://www.cisco.com/c/en/us/support/docs/interfaces-modules/1700-2600-3600-3700-1-port-serial-wan-interface-card/7265-hw-1t-wic.html
Understanding the 1-Port Serial WAN Interface Card (WIC-1T) - Cisco
The 1-port serial WAN interface card (WIC-1T) provides serial connections to remote sites or legacy serial network devices such as Synchronous Data Link...
wan interface cardthe 1wic 1tunderstandingport