Advanced connectivity settings

The default settings for Remote Manager usually work for most situations. The Advanced settings configure the idle timeout for the connection between XBee Gateway and Remote Manager, and the keep-alive settings of the various interfaces (TCP and HTTP for mobile and Ethernet network connections). Only change these settings when the defaults settings do not work properly.

Protocol

Reconnection delay (seconds): This setting controls whether to automatically reconnect to Remote Manager after being disconnected and waiting for the specified amount of time. The time is measured in seconds.

Choose the Never reconnect option if you do not want to automatically reconnect to Remote Manager after a disconnect.

Disconnect inactivity time (seconds): Enables or disables the idle timeout for the Remote Manager connection between device and server. The idle timeout is enabled by default. Specifying “none” disables the idle timeout. Specifying a timeout value enables the idle timeout, which means the connection will be dropped after the specified number of seconds. The minimum value is 300 and the maximum 43200.

In contrast to TCP keep-alives, the timeout managed by the “connidletimeout” option is at the Remote Manager application level. The “connidletimeout” option provides a way to close the connection to the Remote Manager server if no Remote Manager protocol data is sent or received within a specified time frame. That is, the connection is idle with no traffic in or out for that amount of time. This capability is particularly useful for server-initiated connections. When a user on the server side requests a connection be established to a device, that user needs to explicitly terminate the connection when they are done with the device. This timeout allows you to configure the device so that a “forgetful user” does not inadvertently leave the connection in place, which could cost money on a cellular connection if Connectware or TCP keepalives are enabled and transferred needlessly between device and server.

Enable protocol compression: Configures whether RCI command and response text is compressed, when both are passed between the Digi device and the Remote Manager server. This compression primarily affects the size of the data passed when settings or state information are formatted as RCI and conveyed between device and server. Using compression on this RCI text can reduce the size of passed data, and, for cellular products, reduce the cost of reading and writing device settings. When you enable RCI compression, the RCI command and response text is compressed using LIBZ compression when it is sent between device and server. The protocol used to manage and pass data between devices and Remote Manager, known as EDP, internally negotiates whether compression is applied. RCI compression is enabled, or “on” by default to reduce byte count and cost of sending data. As an example of savings, typical cellular router settings will compress to about 8% of its original size, which means that you can send data in far fewer packets and less time, than an uncompressed version of the same data. Only disable RCI compression for technical support and troubleshooting purposes. For example, if you want to eliminate the possibility that this compression is causing some sort of problem.

Socket

Enable TCP no delay: Configures whether use of the TCP no delay option is disabled by default for the Remote Manager connection between device and server, when configuring the device's TCP socket endpoint for that connection. The default is disabled. This default reduces the number of packets sent when the Remote Manager connection is established between device and server. While there is a very slight penalty in terms of added latency, that penalty is very small compared to the relative high latencies for cellular network communications. Reducing the packet count reduces the number of bytes exchanged over the cellular connection, which saves money. The typical start-up data count is reduced from about 7 KB to 4 KB by disabling TCP no delay. The ability to turn on the TCP No delay option is provided for technical support and troubleshooting purposes.

Enable TCP keep-alive: Enables or disables the ability to send TCP keep-alive packets over the client-initiated connection to the Remote Manager server, and whether the device waits before dropping the connection. The default is enabled.

Keep-alive Ethernet and Keep-alive Mobile

These settings control how often keep-alive packets are sent over the device-initiated connection to Remote Manager, and whether the Remote Manager-registered device waits before dropping the connection. Keep-alives for the Remote Manager connection serve three basic purposes:

  1. Keep the Remote Manager connection alive through network infrastructure such as routers, NATs and firewalls.
  2. Inform the other (remote) side of the Remote Manager connection that its peer is still active.
  3. Test the Remote Manager connection to verify whether or not it stopped responding and should be abandoned. Recovery actions are taken as configured in other settings. The Remote Manager-registered device and Remote Manager each perform their own independent monitoring of the Remote Manager connection state (active, idle and missed keep-alives). If Remote Manager protocol messages or data other than keepalives is exchanged over the Remote Manager connection, the idle timers that trigger keep-alives are reset, and the consecutive missed keep-alive counts are cleared to zero.
    • Device send keep-alive interval: Specifies how frequently the device sends a keep-alive packet to Remote Manager if the Remote Manager connection is idle. Remote Manager expects to receive either Remote Manager protocol messages or keep-alive packets from the device at this interval.
    • Server Send Interval: Specifies how frequently the Remote Manager-registered device sends a keep-alive packet to Remote Manager if the Remote Manager connection is idle. Remote Manager expects to receive either Remote Manager protocol messages or keep-alive packets from the Remote Manager-registered device at this interval.
    • Maximum consecutive missed keep-alives: After missing the number of consecutive expected keep-alives specified by this setting, according to the configured intervals, the connection is considered lost and is closed by the device and Remote Manager.

Note The best practice is to set this interval value as long as your application can tolerate to reduce the amount of data traffic.