Cisco ISR4221/K9 ISR 4000 Series 2x GE 1x GE Combo Router — NetworkEquipment.net
Hardware Installation Guide for Cisco 4000 Series Integrated Services Routers - Overview of the Cisco 4000 Series ISRs [Cisco 4000 Series Integrated Services Routers] - Cisco
Original CISCO ISR4221/K9 4000 Gigabit Integrated Services Router Modular Router-Router-Cisco network switch,Cisco Router, NEW used Cisco comparison