http://ftp.draytek.pl/Seria_5510/Instrukcje/V5510_QuickStartGuide_v2.0.pdf

Features

Multi-threat security architecture
Anti-Virus, Anti-Intrusion & Anti-Spam
Intrusion Prevention & Detection (Inline, Realtime)
Support Smart Monitor up to 150 PCs
DrayTek patented MSSI (Multi-Stack Stateful Inspection) provides deep packet inspection
Dual WAN ports with policy-based load balance and fail-over
Robust Stateful Packet Inspection (SPI) firewall with DoS / DDoS protection to protect your network from external attacks
Up to 200 simultaneous VPN tunnels provide deployment of linked branch offices and teleworkers
CSM (Content Security Management) feature provides efficient appliance-based gateway security and content filtering
QoS (Quality of Service) Assurance
3.5G USB modem connectivity for WAN backup
5 Gigabit Ethernet LAN ports