Teleste MPH241 - Switch Protocols and Features; Storm Control and Flow Control; VLAN and STP Support

57 MPH200 series video encoders WebUI user manual
Flooding storm control
MPH200 Ethernet Switch features a ooding control system for con-
straining undesired behavior caused by, for example, loops in the
network or denial-of-service attacks.
SNMP – simple network management protocol
MPH200 Ethernet Switch supports SNMPv2c. SNMP enables network
administrators and control engineers to manage network performance,
nd and solve network problems, and plan for network growth. One
feature of SNMP is that the SNMP agent (in this case a MPH200 switch)
can send SNMP traps to one or more SNMP Hosts. SNMP traps mean
system alarms such as a port link loss or a port enabled for port alarms
or the switch temperature exceeding a predened threshold.
Flow control
Flow control can be enabled or disabled on a per-port basis from the
command line interface or from the WEB interface. If ow control is
enabled for a port the associated PHY will be set to advertise support of
“Symmetric Pause”, but not “Asymmetric Pause”. If the station con-
nected to the port also supports “Symmetric Pause”, ow control will be
enabled on the switch port. Watermarks are set to hard-coded values.
Different values are used depending on whether ow control is enabled
or not and on current speed.
Ageing
To prevent that an automatically learned MAC address of a station that
has been detached will remain in the MAC address table permanently,
the ageing function in the switch is activated on a regular basis. The
period for doing the ageing function is determined by the ageing time
parameter. Given the ageing mechanism in the switch, the period must
be half the value of the ageing time parameter in order to make the
ageing time parameter comply with IEEE 802.1D. For instance, if the
ageing time parameter is 300 seconds, the period must be 150 seconds
to ensure that an unused MAC address will not remain in the MAC
address table for more than 300 seconds.The ageing time parameter can
be set from the command line interface. Default value is 300 seconds.
Setting the ageing time parameter to 0 disables the ageing function.
VLAN support
VLANs are collections of switching ports that comprise a single broad-
cast domain. Packets are classied as belonging to a VLAN based on
either the VLAN tag or based on a combination of the ingress port and
packet contents. Packets sharing common attributes can be grouped in
the same VLAN.
STP – spanning tree protocol
802.1d Spanning tree is a standard Layer 2 switch requirement that
allows bridges to automatically prevent and resolve L2 forwarding loops.
Switches exchange conguration messages using specically formatted
frames and selectively enable and disable forwarding on ports.