Cisco 2921 Integrated Services Router (ISR) delivers highly secure data, voice, video, and application services for small offices. Key features include:

3 Integrated 10/100/1000 Ethernet ports with 1 port capable of RJ-45 or SFP connectivity
1 service module slot
4 Enhanced High-Speed WAN Interface Card (EHWIC) slots
3 onboard digital signal processor slots
1 internal service module slot for application services
Fully integrated power distribution to modules supporting 802.3af Power over Ethernet (PoE) and Cisco Enhanced PoE
Security
Embedded hardware-accelerated VPN encryption
Secure collaborative communications with Group Encrypted Transport VPN, Dynamic Multipoint VPN, or Enhanced Easy VPN
Integrated threat control using Cisco IOS Firewall, Cisco IOS Zone-Based Firewall, Cisco IOS IPS, and Cisco IOS Content Filtering
Identity management: Intelligently protecting endpoints using authentication, authorization, and accounting (AAA), and public key infrastructure
Voice
High-density packet voice DSP module, optimized for voice and video support
Standards-certified VoiceXML browser services
Cisco Unified Border Element capabilities
Cisco Unity Express voicemail support
Support for Cisco Communications Manager Express and Survivable Remote Site Telephony