The Cisco VG350, VG224, VG204XM, and VG202XM are part Cisco IOS® software-based VG series stand-alone analog voice gateways. The Cisco VG350 is a high-density 160-port gateway, the Cisco VG224 is a 24-port gateway, and the Cisco VG204XM and VG202XM are low-density 4- and 2-port gateways, respectively. These gateways connect analog phones, fax machines, modems, and speakerphones to an enterprise voice system based on Cisco Unified Communications Manager (Unified CM). Having these devices tightly integrated with the IP-based phone system is advantageous for increased manageability, scalability, and cost-effectiveness (refer to Figure 5 later in this document). Commercial businesses can also use these gateways with Cisco Unified Communications Manager Express to effectively augment an integrated-services-router (ISR) environment. Both topology environments support business needs ranging from high to low concentrations of analog voice ports for modem calls, fax calls, and analog supplementary services.