Specifications

ALAXALA Ring Configuration Guide (Edition 1)

1.2 Features of the Ring Protocol

(1) Ethernet-based ring network

The Ring Protocol is an Ethernet-based Layer 2 network redundancy protocol. Whereas conventional ring

networks typically use dual-link fiber optics such as with FDDI, you can use the Ring Protocol to build ring

networks using Ethernet.

(2) Simple operation method

Networks using the Ring Protocol have a simple configuration consisting of one master node and the other

switches running as transit nodes. Ring status monitoring (for failure and recovery from failure) and path

switching operations are primarily performed by the master node, and the other transit nodes switch paths

according to instructions from the master node.

(3) Control frames

The Ring Protocol uses its own control frames. These control frames are used by the master node for

monitoring the ring status, and for prompting path switching from the master node to transit nodes. Because

control-frame sending and reception is performed on a special VLAN, data and control frames are not sent on the

same VLAN, unlike typical spanning trees. In addition, control frames are processed with a higher priority so

that larger data traffic will not affect them.

(4) Load balancing method

Multiple VLANs used within a ring are aggregated logically by group, and data flow can be set to clockwise or

counterclockwise from the master node. This is useful for load balancing and dividing paths by VLAN.

1.3 Glossary

Table 1.3-1 Glossary of the Ring terms

No. Term Description

Master node A node that monitors and detects failures and recovery from failures in a

ring. The master node also controls the logical status (FWD or BLK) of

ports in the ring according to the ring status and prevents a loop. Every

single ring must have one master node.

Transit node A node that transfers data. Unlike the master node, this node does not

monitor failures or recovery from failures in the ring.

Control VLAN A VLAN on which control frames are sent and received. Each ring has a

unique VLAN ID. You cannot use the same VLAN for both control and

data transfer VLANs.

Data transfer VLAN A VLAN on which data is sent and received. Data transfer VLANs are

associated with a ring VLAN group and subject to switching when failure

occurs.

Ring port A port connected to a node in the ring. This port sends and receives data

frames on data transfer VLANs and control frames on the control VLAN.

Primary port A ring port for which the master node sets the ring VLAN status to

Forwarding when the ring is in normal condition.

Secondary port A ring port for which the master node sets the ring VLAN status to

Blocking when the ring is in normal condition. Setting the status to

Blocking prevents data looping. When a ring failure occurs, the port status

is switched from Blocking to Forwarding to form an alternate path.