ETHERLINK II - Repeater
Manual
Page 34 of 106
A group of LAN Ports
(Ethernet interface) means that a connector (or connectors) is located on
the front panel of the device. This port can serve both as a
Trunk port
and an
Access port
.
The
Trunk port
is a port at the input and output of which all present packets have the VLAN
format, namely, the Ethernet frame with a header, determining the number of the VLAN and
QoS (Quality of Service) to which the IP packet belongs. Special equipment, which supports the
VLAN, is connected to the Trunk port. A PC with a standard network interface card cannot be
connected to the Trunk port.
The
Access port
is a port at the input and output of which all present packets have a standard
Ethernet format (without the additional two bytes for the header). A PC with a standard network
interface card can be connected to the Access port.
Ethernet packets of the VLAN format are always transmitted over the xDSL or E1 interfaces in
S-Access Etherlink_II devices. In this case, the data of Assess ports are first transformed into
Ethernet packets of the VLAN format according to the specified rules and then are transmitted
over the line interface.
A VLAN number and a QoS priority level, which are used by default to convert Ethernet packets
into the VLAN format, are assigned to the
Access port
. In addition, every unit contains a table
of static MAC addresses of devices, so that each device can have a VLAN number and a QoS
priority level (a table of special MAC addresses). This table can contain up to 8 MAC addresses.
If a packet is received from the Access port, and the MAC address of the packet sender is in
this table, a header with the necessary VLAN number and the QoS priority will be assigned to
this packet before transmitting it to the Trunk port. Otherwise, a default VLAN number and QoS
priority will be assigned to the packet.
Physical ports (if there are some of them) are united into a LAN group in the device software. All
physical Ethernet interfaces (the LAN group) have identical VLAN and QoS settings. A
possibility is also provisioned to configure separately the transmission rate and duplex for each
physical interface (ETH1
– ETH4).
A group of DSL ports (WAN1
– WAN4)
(xDSL interface) means that Ethernet data can be
mapped onto the specified time slots of the xDSL interface by using the switch of 64 kbit/s time
slots. In this case, this port always serves as a
Trunk port
, i.e., data received from
Access
ports
are first transformed into Ethernet packets of the VLAN format according to the rules
specified and then are transmitted over the xDSL interface.
A group of E1 ports (WAN1
– WAN4)
(E1 interface) means that that Ethernet data can be
mapped onto the specified time slots of the E1 interface by using the switch of 64-kbit/s time
slots. In this case, this port always serves as a
Trunk port
.
A virtual management port (INT)
(Virtual management port) is an internal device management
program. IP-address of this device is the logical address of the management program. For
example, to open a session for managing a remote device (i.e., to exchange data between a
control and management PC and the device program), the IP-address of this device should be
specified in the Telnet program. At the physical layer, the MAC address of the device is also the
management program address, which is contained in the Ethernet frame.
Note: As a rule the data of the management port have the highest priority (for example, QoS =
7).
3.6.3 An integrated switch of 64-kbit/s time slots
3.6.3.1 E1 mode (transmission of only time slots of E1 streams)
In this mode, only time slots of E1 streams are transmitted over xDSL lines.
Time slots of the E1 stream are transmitted in the xDSL frame according to ITU-T Rec. G.991.2.
