The 3120's design uses a Broadcom BCM6349 residential gateway processor, Broadcom BCM5335 10/100 switch, 64 MB of RAM and 16 MB of flash. There is no dedicated VPN co-processor.
The feature set is extensive and includes VoIP specific QoS and monitoring and a full-featured SPI router that supports bridging and non-NAT routing. The built-in 10/100 managed switch includes VLAN, link aggregation, port mirroring and access control.
The 3120 supports up to five simultaneous IPSec VPN tunnels with DES, 3DES, and AES encryption and XAUTH, Digital certificate, Pre-Shared Key and Secure ID authentication. The router can also centrally manage multiple Adtran wireless access points.
Routing performance measured around 30 Mbps in both unidirectional and simultaneous bidirectional tests. Maximum Simultaneous Connections handling topped out at 180 sessions.
Updated 7/9/2008: Read the full review.