User`s manual

Chapter 1 Overview
18
1.6.3 Ethernet Switch Subsystem
1.6.3.1 Ethernet Switch Description
The MUXpro includes an Ethernet switch with VLAN support that fully complies
with the IEEE 802.3/Ethernet V.2 standards, has user-selectable forwarding
algorithms, and provides extensive support for QoS features. The switch has
memory-based switch fabric with true non-blocking switching performance(for
100Mb/s speed, 64byte frame, 148800pps throughput).
The switch collects a wide range of performance monitoring parameters, which
can be read by management. The Ethernet switch has seven ports:
 Four external ports, connecting to LAN 1 LAN interface, LAN 2 LAN interface,
LAN 3 LAN interface and LAN 4 LAN interface respectively.
 Four VCG groups. These ports connect to the encapsulation function, part of
the Ethernet mapper subsystem, which processes the traffic for transmission
via SDH network using virtual concatenation. Each port connects to one of the
virtually concatenated groups 1 and 4.
 Management port, connected internally to the MUXpro management
subsystem.
An independent MAC controller that performs all the functions required by the
IEEE 802.3 protocol supports each port.
The frames passed by the MAC controller are analyzed by the ingress policy
controller of the corresponding port before being transferred to an internal queue
controller, which controls the frame egress priorities and inserts them in four
separate queues. The queues are connected to the ports through the port egress
policy controllers. This approach provides full control over traffic flow, and ensures
that congestion at one port does not affect other ports.
1.6.3.2 Flow Control Options
The user can enable flow control for the switch ports. When flow control is enabled,
it is always activated only on the port (or ports) involved in congestion; on the
contrary, other ports are not affected.
Flow control is available in both the half-duplex and full-duplex modes: