Communications tab

The Communications tab allows you to configure the behavior of the AVEVA communications protocol. The Communications tab includes the following configurable fields:

• SuiteLink: TCP/IP based communication protocol

• Network Message Exchange (NMX): AVEVA application communication protocol

  

  Note: The Communications tab will be hidden if you do not install a product that uses SuiteLink or NMX communications.

SuiteLink mixed mode setting

Prior to System Platform 2023, enabling the System Management Server, either by connecting to an existing server or by setting this machine as the System Management Server resulted in the following behavior for SuiteLink connections:

• The system first attempted to make a secure connection between a SuiteLink client and the SuiteLink server.

• If a secure connection could not be established, an unsecured SuiteLink connection was made. Users were not notified if the SuiteLink connection was not secure.

As of System Platform 2023, the System Platform Configurator includes an option to force all communications to be encrypted for SuiteLink connections.

• Mixed mode enabled: This is the default setting if you are upgrading a node from a prior release. With the checkbox set to true (checked), the behavior described above is used, in which unsecured connections are allowed. This mimics legacy System Platform behavior, prior to the System Platform 2023 release. This setting is not recommended except for the use cases listed below.

• Mixed mode disabled: This is the default setting for new installations. With the checkbox set to false (unchecked), client connections to the SuiteLink server are only successful if the connection is secured, that is both nodes must configured to use the System Management Server. This option ensures that the connection between the SuiteLink Server and SuiteLink clients is always secure (encrypted). If a secure connection is not available, the connection will not be allowed. A secure connection between client and server is only possible if both are configured to use the System Management Server.

Mixed mode use cases

Mixed mode is recommended for use under the following conditions:

• While upgrading an existing System Platform installation (performing a node-by-node upgrade). Reset the mode to disable mixed mode after the upgrade is complete.

• To support legacy applications that do not use encrypted SuiteLink communications.

  Note: Whenever the SuiteLink communication mode is changed, a system restart is required before the new mode will take effect.

NMX user access setting

The AVEVA Network Message Exchange (NMX) is an application communication protocol that leverages a DCOM-based transport mechanism for communication between nodes. For new installations, the default setting is to disable access for all users to NMX communications. If you are upgrading an existing System Platform installation, access for all users is enabled by default. Reset the mode to restrict access after you complete the node-by-node upgrade.

• Enable access to NMX for all users: This is the default setting if you are upgrading a node from a prior release. Allowing access for all users is not recommended except for the use cases listed below.

• Disable access to NMX for all users: This is the default setting for new installations. With the checkbox set to false (unchecked), NMX communication is allowed only for the users and accounts that require it. NMX access is allowed for:

  • Members of the OS User Group aaRuntimeUsers

  • Members of the OS Administrators group

  • The System Platform Network Account

  • The local system account (NT System)

Access to NMX for all users use cases

Access for all users is recommended for use under the following conditions:

• While upgrading an existing System Platform installation (performing a node-by-node upgrade). Reset the mode to disable access for all users after the upgrade is complete.

• To support legacy applications that require access for all users.

  Note: Whenever the NMX mode is changed, a system restart is required before the new mode will take effect.