Engineering Documentation

Chapter 2 – Network Electrical Systems
Dual Port Ethernet Controller Topology Basics
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Requirements for Fault Tolerant Loop Topology with RSTP
● Ethernet Bridges and Managed switches with support for RSTP.
● RSTP is interoperable with dual port Ethernet controllers which include embedded
3 port switch supporting STP and one IP Address
● RSTP allows larger loops of up to 20 controllers installed in a line configuration
with maximum cable distance of 1890 m (6200 ft) consisting of 21 x 90 m (295 ft)
runs between RJ45 jacks
● RSTP allows faster 10-30 second network fault recovery using discarding port
● Network management using Internet Group Management Protocol (IGMP) allows
alarming as otherwise, a line failure by the customer remains unknown
● Multiple STP loops may be installed in parallel in RSTP configuration as long as
no two loops exceed 40 controllers
● No third-party devices or other switches will be installed in the loop (BPDU
messages must be transmitted transparently to the management switch)
Fig. 7: Logical Diagram multiple Lines of up to 20 Dual Port Ethernet Controllers within a RSTP
Configuration (fault tolerant).