Lancom Systems Router 1721 VPN - ADSL/ISDN Annex B. DSL connection type: ADSL. Switching protocols: Ethernet, Routing protocols: RIP, RIP-1, RIP-2, SAP, VRRP, Data link protocols: Ethernet, Fast Ethernet, PPP. Authentication method: SSH, RADIUS. Certification: CE, EN 60950, EN55022, EN55024. Operating temperature range (T-T): 5 - 40 °C, Operating relative humidity range: 0 - 80 %