User guide
Configuring Network Services Software Upgrade with EPSR
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AlliedView NMS Administration Guide
6.20 Software Upgrade with EPSR
6.20.1 Overview
Section 5.3.9 explains the software download application and how it can be used to control the download process for one or
more devices and prevent errors.
A special situation occurs when the devices are part of an EPSR configuration, because the order in which the devices are
downloaded will prevent service outage. Following are the rules/constraints that must be followed to ensure nodes in an
EPSR configuration are upgraded without loss of service:
• Whenever a set of nodes is selected to be upgraded, if any of the nodes contain EPS Rings, it is possible that additional
nodes, not specified in the original set, will have to be upgraded before the specified nodes.
• Any additional node of an EPSR may then have other EPSRs on it that require additional nodes to be upgraded before
others.
• If any EPSR in the chain of EPSRs is misconfigured then it may not be possible to derive the upgrade order of its nodes.
(The preferred order is: Master, Secondary Transit, around to Primary Transit.) It is possible that another valid EPSR will
require a node from this invalid EPSR to be upgraded before the valid one can be upgraded.
• The upgrade of one node should be complete before the upgrade of another node is begun.
• If an EPSR is only partially managed, so that the topology is linear from Master to Secondary Transit, but not a complete
ring back to the Primary Transit, then the partial ring should still be upgraded (under the assumption that any unmanaged
remaining Transit nodes of the ring will be upgraded subsequently, either via CLI or another management system).
• Even when all EPSRs are valid there may still be loops in the precedence order (e.g., two EPSRs on the same ports, going
in opposite directions will result in precedence loops.) Loops in the precedence order indicate that there is no order of
upgrade among the nodes that will satisfy all EPSR's constraints. In this case, the user will have to modify or ignore certain
EPSR vlans to form an upgradeable set of ring configurations.
In release 9.0, the download application is enhanced so that when a device is selected for download, the EPSR configuration
is checked so that these rules are followed:
• If the devices chosen are part of an EPSR configuration, and there are no conflicts with the configuration rules listed
above, the devices are upgraded in the proper order, and so service is not disrupted.
• If there is an ambiguity or conflict in the EPSR configuration, GUIs appear informing that the AlliedView NMS needs to
resolve these conflicts before proceeding.
• If the selected device set does not include those that are part of the EPSR configuration, GUIs appear informing that the
AlliedView NMS needs to include these devices before proceeding.
• If the EPSR has not been configured correctly initially, the feature cannot work, and a GUI with the appropriate error
message appears; the user can choose to upgrade anyway if a potential loss of service is either acceptable or data traffic is
not running over the VLANs.
Note: The Software Configuration feature is included in Section 5, since it can perform actions on a specific device. However, since
this feature checks multiple devices it is considered a network service.
6.20.2 Upgrading all Nodes for an EPSR Ring
Following is an example that shows how the feature works when upgrading multiple devices that include an EPSR Control
and Data VLAN The administrator wishes to upgrade the three devices that make an EPSR ring, as shown in the following
figures.