Specifications

ALAXALA Ring Configuration Guide (Edition 1)
Copyright © 2008, ALAXALA Networks Corporation. All rights reserved.
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3.2.2 Important points on constructing a system
(1) The Spanning Tree Protocol (STP) must be disabled.
By default, STP by means of PVST+ runs on AX series switches. However, you need to disable STP because
this configuration does not use STP.
(2) In addition to VLANs for data communication, a control VLAN is required.
With the Ring Protocol, a special VLAN is used for controlling the topology of the ring, while normal VLANs
are used for typical data communication. This special VLAN is required per ring (that is, per ring ID). For a
multi-ring configuration, a control VLAN is required for both the shared link monitoring ring (O-shaped ring) and
shared link non-monitoring ring (C-shaped ring).
Therefore, when you assign VLANs, you need to take the ring control VLAN into account.
(3) VLANs for data communication need to be defined in the VLAN mappings.
You need to define data communication VLANs used for the Ring Protocol in the VLAN mappings.
For a multi-ring that shares VLANs, you need to configure multiple rings that use the same data VLANs for a
single device. However, you can simplify the configuration by these VLAN mappings (because you do not have
to configure the same data transfer VLAN for every single ring), which allows you to prevent a loop due to
configuration errors or other trouble.
(4) The primary port is always on the shared link side when the shared node is the master.
As shown in the following configuration, if the devices placed on both ends of the shared link for the shared
link monitoring ring (O-shaped ring) and shared link non-monitoring ring (C-shaped ring) are master nodes, the
ports on the shared link side are the primary ports, regardless of whether the device is the master node for either
the shared link monitoring or non-monitoring ring. This also means that load balancing is not possible by
specifying different primary ports for each VLAN group. You need to be careful about this when you configure a
network.
With this restriction in a shared link, you can take the following load balancing methods:
- Set up a configuration in which the shared node is not the master. For the ring in which the shared node is not
the master node, you can specify different primary ports for each VLAN group.
- If the load is assumed to be concentrated on the shared link, you can set up a configuration that can handle a
larger load by, for example, configuring link aggregation for the shared link.
For example, in the configuration on the
left, load on the shared link can be
reduced by grouping together VLANs
used in the building A into VLAN group 1
and VLANs for communication with
outside of the building A into VLAN
group 2.
O-sha
p
ed rin
g
maste
r
C-shaped ring maste
r
O-shaped ring
C-shaped ring
VLAN Gr.2
VLAN Gr.1
Building A
Switches on each floor
O-shaped ring master
C-shaped ring master
O-shaped ring
C-shaped ring
Building A
Switches on each floor
As shown in the example on the left, if
the load is assumed to be concentrated on
the shared link, increase the bandwidth by
using a faster line for the shared link (1G
bps line for a 100M bps ring, 10G bps line
for a 1G bps line, etc.) or by implementing
link aggregation.