Connecting TX boards for redundancy

Use the redundancy feature to enable the system to detect and recover from the failure of signaling links on a TX 4000 board, the failure of a signaling node, or the failure of the TX 4000 board itself.

In a redundant configuration, each pair of TX boards is connected through a private Ethernet connection. If other devices are connected to the private Ethernet link, avoid overloading the link. Packets can be lost between the redundant TX boards if the connection is overloaded.

This topic describes dual-node redundant signaling and single-node redundant signaling for the following types of configurations:

TDM configuration

To connect a TX 4000 board to its redundant mate in a TDM configuration, use a Category 5 shielded twisted pair (STP) crossover cable. With the crossover cable, connect Ethernet 1 on the primary board to Ethernet 1 on the backup board.

You must specify the IP address of the TX board’s redundant mate using the mate command in the txconfig utility. You must also define the IP interface address using the ifcreate command (for interface 1) in the txconfig utility. For more information, refer to the Dialogic® NaturalAccess™ Signaling Software Configuration Manual.

Dual-node redundant signaling server

The following illustration shows how to set up two TX 4000 boards based on a dual-node redundant signaling server in a TDM configuration. The boards are located in two separate chassis to ensure board-level and system-level redundancy.

 

Single-node redundant signaling server

The following illustration shows how to set up two TX 4000 boards based on the single-node signaling server in a TDM configuration. The boards are located in the same chassis to ensure board-level redundancy.

 

IP network configuration

To connect a TX 4000 board to its redundant mate in an IP network configuration, use a Category 5 shielded twisted pair (STP) crossover cable. Using the crossover cable, connect Ethernet 1 on the primary board to Ethernet 1 on the backup board. Using standard Ethernet cables, connect the Ethernet 2 connectors on both boards to the IP network connectors.

Note: Dialogic recommends using a private Ethernet link to connect the redundant boards to avoid loss or delay of vital checkpoint messages. However, if each board in the redundant pair requires multi-homing, you can use Ethernet 1 for both the redundant pathway and for SIGTRAN network access. In this configuration, the Ethernet 1 on each board is connected to what is shown as an IP network cloud in the illustrations that follow (just as the Ethernet 2 connectors are). Be aware that this greatly increases the chance of lost or delayed checkpoint messages which can result in the backup having outdated information.

You must specify the IP address of the TX board’s redundant mate using the mate command in the txconfig utility. You must also define the IP interface address using the ifcreate command (for interface 1) in the txconfig utility. For more information, refer to the Dialogic® NaturalAccess™ Signaling Software Configuration Manual.

Dual-node redundant signaling server

The following illustration shows how to set up two TX 4000 boards based on a dual-node redundant signaling server in an IP network configuration. The boards are located in two separate chassis to ensure board-level and system-level redundancy.

Single-node redundant signaling server

The following illustration shows how to set up two TX 4000 boards based on a single-node signaling server in an IP network configuration. The boards are located in the same chassis to ensure board-level redundancy.

For more information on SS7 redundancy, refer to the Dialogic® TX Series SS7 Boards Health Management Developer's Reference Manual.