Use Existing Infrastructure : Cisco VoiceXML service can be combined with Cisco IOS Software Voice Gateway services or used as a standalone, dedicated VoiceXML browser gateway. VoiceXML allows the enterprise to reuse the existing Web infrastructure. Flexible Architecture : Cisco IOS VoiceXML Browser can be co-located with Cisco Unified CVP at a single site or it can be distributed throughout the enterprise branch network with Cisco Unified CVP and media servers centralized at headquarters or regional sites. Standards Based: Cisco IOS VoiceXML Browser is VoiceXML 2.0-compliant. Voice gateways provide access to the public switched telephone network (PSTN)-, H.323-, or Session Initiation Protocol (SIP)-based networks. Cisco IOS VoiceXML Browser supports the VoiceXML 2.1 and Media Resource Control Protocol (MRCP) Version 2. Resilient and Scalable : A keepalive feature ensures calls in process and new calls can be directed to a customer-defined basic automatic call distributor (ACD) queue(s) on the voice gateway regardless of network conditions. Distributed architecture allows IVR calls to be rerouted and process-loaded. Cisco Unified CVP provides centralized, sophisticated operations, administration, management, and provision (OAM&P) for the gateways Security: Secure HTTP over Secure Sockets Layer (SSL) to secure media communications between the browser and secured servers. Inherent security is delivered through Cisco IOS Software, including IP Security (IPsec), VPN, and hardware-based encryption.