Nortel VPN Router 1750 500 tunnels. Networking standards: IEEE 802.1p, IEEE 802.1Q. Routing protocols: BGP-4, Management protocols: SNMP, HTTP, Supported network protocols: PPTP, L2TP, IPSec, PPPoE, L2F. Authentication method: RADIUS, X.509, LDAP. Internal memory: 128 MB. Operating temperature range (T-T): 0 - 40 °C