NETWORK AND MANAGEMENT OVERVIEW

Through the console menus, you can configure the Megabit Modem CRA-C as a bridge to forward Ethernet data based on MAC addresses or as a router to route Ethernet data based on IP addresses. Additionally, you can configure parameters for management and encapsulation protocols using the Megabit Modem CRA-C console menus.

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MAC layer bridging and spanning tree protocol

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Static IP routing

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Management protocols

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Network configuration and image code download

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Encapsulation protocols

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MAC Layer Bridging and Spanning Tree Protocol

MAC Layer Bridging. A bridge moves information across an internetwork from a source to a destination at the link layer (of an OSI reference model). The information is sent to a physical address known as a Media Access Control (MAC) address.

The Megabit Modem CRA-C provides transparent Ethernet MAC level bridging. It is a completely self-contained bridge with a CPU, memory subsystems (RAM, Flash, etc.), an Ethernet controller and Ethernet drivers, and other glue logic. It provides complete main bridging tasks of learning, forwarding, filtering, and hashing/buffer management. Additionally, it offers 802.1d Spanning Tree protocol, packet encapsulation (via HDLC or PPP framing), and other local tasks.

Forwarding performance is at 2.7 kpps (kilo packets per second) and filtering performance is at full Ethernet rate of 14 kpps for 64-byte frames (minimum size).

Spanning Tree. Spanning Tree protocol eliminates loops in a LAN topology by partitioning out redundant links between LAN segments. This ensures that there is only one path, or link, between any two nodes on the network. If this link goes down, Spanning Tree enables the partitioned links to create a new loop-free topology, if possible. An example of the active topology is shown in Figure 9.

Megabit Modem CRA-C User Manual

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