10Base-T/100Base-TX/E3 Converter
Operating Manual
IOA170-1A 7
January 2006
3. Function description
3.1. Function properties
The device has a 3-port Ethernet switch, two ports are used to connect external network
segments, the third port configured as MII (Medium Independent Interface) is attached by a bridge
system to the E3 transreceiver. The Ethernet interfaces automatically switch to MDI or MDI-X
mode depending on the type of connecting cable. The bridge places a separate Ethernet frame
from the switch in the HDLC frame and transparently transmits it to the E3 transreceiver and then
next to the telecom network.
The receipt of a frame from a telecom network, extraction of HDLC frame with E3 stream
followed by extraction of an Ethernet frame from the HDLC frame and forwarding it to an
appropriate port switch depending on to which port the station is attached to takes place during
contrary transmission direction. The device filters local traffic transmitted inside the Ethernet
network attached to the switch ports and only retransmits traffic between networks to distant
network segments. It can also filter DHCP, NetBios and Broadcast frames.
A microcontroller enables configuration of the device and to monitor its operation status.
Servicing of the following protocols has been implemented: SNMP – version 1 as well as protocol
group services of TCP/IP – TCP (transmission control protocol), UDP (user diagram protocol ), IP
(Internet protocol), ICMP (Internet control message protocol).
Ethernet interface supports two 10Mbit/s and 100 Mbit/s physical layer implementations
with the auto-negotiation ability, which enables connection at the highest speed available – Table
3-1. LED indicator lights signal the connection mode.
Table 3-1. Connection sequence choice in auto-negotiation.
Sequence Connection
mode
1 100BASE-TX
full-duplex
2 100BASE-TX
half-duplex
3 10BASE-T
full-duplex
4 10BASE-T
half-duplex
The converter periodically reviews stored addresses in the MAC source board of addresses
and removes those, which are there over 300 seconds.
3.2 Clock
The converter may transmit data in the E3/G.703 transmission direction with a clock from two
sources:
•
from an internal 34,368 MHz
±
20 ppm, frequency quartz generator,
MASTER
operation
mode
•
from the opposite E3/G.703 transmission direction clock rerun,
SLAVE
operation mode
3.3 Diagnostic and signal indicating systems
The converter automatically controls the E3 linear interface and Ethernet interface signal
parameters as well as detects and signals the following statuses and amounts:
