The Cisco 3925 Integrated Services Router (ISR) delivers highly secure data, voice, video, and application services to small branch offices. Key features include:

- Modular Services Performance Engine (SPE) 100, which can be upgraded for even higher performance as next-generation WAN environments evolve
- 3 integrated 10/100/1000 Ethernet ports with 2 ports capable of RJ-45 or SFP connectivity
- 2 service module slots
- 4 Enhanced High-Speed WAN Interface Card (EHWIC) slots
- 4 onboard digital signal processor (DSP) slots
- 1 Internal Services Module slot
- Dual integrated power supplies
- Fully integrated power distribution to modules supporting 802.3af Power over Ethernet
- A universal IOS image that lets you deploy new IOS services quickly

Security
- Embedded hardware-accelerated VPN encryption for secure collaboration
- Integrated threat control using Cisco IOS Firewall, Cisco IOS Zone-Based Firewall, Cisco IOS IPS, and Cisco IOS Content Filtering
- Identity management using authentication, authorization, and accounting (AAA) and public key infrastructure

Unified Communications
- High-density-packet voice DSP module, optimized for voice and video support
- Standards-certified VoiceXML browser services
- Cisco Unified Border Element capabilities for up to 800 sessions
- Cisco Unity Express voicemail support
- Support for Cisco Communications Manager Express and Survivable Remote Site Telephony