3Com 3CRUS2475 User Manual page 314

Feature
Power over Ethernet
Private VLANs
RADIUS Clients
Rapid Spanning Tree
Remote Monitoring
Self-Learning MAC Addresses
SNMP Alarms and Trap Logs
SNMP Versions 1, 2 and 3
SNTP
Description
Power over Ethernet (PoE) provide power to devices over existing
LAN cabling, without updating or modifying the network
infrastructure. Power over Ethernet removes the necessity of placing
network devices next to power sources. Power over Ethernet can be
used in the following applications:
IP Phones
Wireless Access Points
IP Gateways
PDAs
Audio and video remote monitoring
Private VLAN ports are a Layer 2 security feature which provide
isolation between ports within the same Broadcast domain.
RADIUS is a client/server-based protocol. A RADIUS server maintains
a user database, which contains per-user authentication
information, such as user name, password and accounting
information.
Spanning Tree can take 30-60 seconds for each host to decide
whether its ports are actively forwarding traffic. Rapid Spanning
Tree (RSTP) detects uses of network topologies to enable faster
convergence, without creating forwarding loops.
Remote Monitoring (RMON) is an extension to SNMP, which
provides comprehensive network traffic monitoring capabilities (as
opposed to SNMP which allows network device management and
monitoring). RMON is a standard MIB that defines current and
historical MAC-layer statistics and control objects, allowing
real-time information to be captured across the entire network.
The device enables automatic MAC address learning from incoming
packets. The MAC addresses are stored in the Bridging Table
The system logs events with severity codes and timestamps. Events
are sent as SNMP traps to a Trap Recipient List.
Simple Network Management Protocol (SNMP) over the UDP/IP
protocol controls access to the system, a list of community entries is
defined, each of which consists of a community string and its access
privileges. There are 3 levels of SNMP security read-only, read-write
and super. Only a super user can access the community table.
The Simple Network Time Protocol (SNTP) assures accurate network
Ethernet Switch clock time synchronization up to the millisecond.
Time synchronization is performed by a network SNTP server. Time
sources are established by Stratums. Stratums define the distance
from the reference clock. The higher the stratum (where zero is the
highest), the more accurate the clock.
Unified Switch 24 Features 313