GarrettCom Magnum MNS-6K - Manual (Page 152)

M A G N U M 6 K S W I T C H E S , M N S - 6 K U S E R G U I D E
1. The S-Ring feature is a separately licensed module for the MNS-6K software
package. This module must be enabled by means of a software key
2. Only one switch is the “Ring Master”. That switch has S-Ring Software
authorized (enabled) for that device. Thus only one license key is needed per
ring (and not per switch)
3. There can be multiple S-Rings on a given Magnum 6K switch. There can be
multiple ring topologies in a network. Each ring has to be a separate ring. Ring
of rings or overlapping rings are not supported at this time
4. S-Ring topologies support one failure in the network. A second failure may
create isolated network islands
5. At least one untagged VLAN must be available for the BPDU’s to propagate
through the network to update RSTP/STP status
6. S-Ring faults can be software signaled to alarm contacts.
RS-Ring concepts
Today, more and more situations demand a network to be
built using managed switches. These situations also demand
a faster recovery time in case of a network failure. The
topologies have to be simple for maintenance and other reasons. In these situations,
a ring topology provides fault tolerance with the simplicity. RS-Ring feature can be
used on managed Magnum 6K family of switches. RS-Ring provides the simple ring
topology and provides faster recovery times than S-Ring or STP/RSTP.
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RS-Ring is built upon networking software standards such as Rapid Spanning Tree
Protocol (RSTP) based on IEEE 802.1w. RS-Ring defines two ports on each switch
which participates in the ring topology and works with the RSTP tree structure. RS-
Ring requires RSTP to be configured across all switches and uses the underlying
RSTP protocol to provide simplicity in configuration as well as rapid recovery in the
RS-Ring topology. The recovery times for RS-Ring based networks are within
milliseconds. While the recovery time for STP devices is in tens of seconds (typically
30 seconds in most networks) or sub second to a few seconds for RSTP networks,
RS-Ring offers recovery times typically in less than 100 milliseconds. The biggest
advantage of RS-Ring, besides the fast recovery time, is the defined topology which
makes the network manageable. RS-Ring is configured on Magnum 6K family of
switches and requires RSTP to be enabled on all switches participating in the RS-
Ring. RS-Ring cannot be used in a multi-vendor environment.
RS-Ring operates from specifically defined port pairs that participate in a ring-
topology. Each of the two ends of a ring must be connected to two ports in a
Magnum 6K Switch that is enabled with the RS-Ring software. The end points of the
ring provide an alternate path to reach the switch that has failed. Some items for
using RS-Ring are as follows:
1. Faster recover times than S-Ring or RSTP are needed by the network
2. The RS-Ring feature is a separately licensed module for the MNS-6K software
package. This module must be enabled by means of a software key.
3. The same key can be used for either S-Ring or RS-Ring
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