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SS7 Redundancy: Disabling, Reconfiguring and Querying

Overview

This procedure describes how to disable, reconfigure and query SS7 redundancy. If you need to alter redundancy on a live system, follow the procedure, In-Service Upgrades.

Before you begin

Before you disable SS7 redundancy using the CCS Redundancy Configure message, you must be prepared to allow both SS7 cards to reset and for all call processing to stop.

Disabling Redundancy

Redundancy can be disabled either automatically by the CSP or by the host with the CCS Redundancy Configure message. When redundancy is disabled, one of the following values is sent to the host in the CCS Redundancy Report message:

Redundancy Disabled Values

0x20 | Primary card is out of service
0x21 | Secondary card is out of service
0x22 | Redundant I/O card is removed
0x24 | Redundancy disabled by the host
0x25 | Primary card reset during synchronization
0x26 | Secondary card reset during synchronization
0x27 | Primary card detected link failure to mate during synchronization state (1 or 2)
0x28 | Secondary card detected link failure to mate during synchronization state (1 or 2)
0x29 | Primary card detected link failure to mate while in stable state (3 or 4)
0x30 | Secondary card detected link failure to mate while in stable state (3 or 4)

CSP Disabling of Redundancy

Redundancy is automatically disabled by the CSP under the following conditions:

• Either SS7 card is removed or taken out of service.

• The I/O card is removed.

• A Matrix Controller switchover occurs while the SS7 cards are synchronizing.

See SS7 Card Switchover.

Host Disabling of Redundancy

You can disable the redundancy configuration from the host by sending the CCS Redundancy Configure message and setting the Secondary Slot field to 0xFF. Both SS7 cards reset and come back in service as independent cards with the default configuration. You must resend non-default SS7 configuration to both cards.

To disable redundancy without resetting both SS7 cards, remove one of the cards or take it out of service with the Service State Configure message.

Disabling redundancy with the CCS Redundancy Configure message resets both SS7 cards and stops all SS7 call processing.

Reconfiguring Redundancy

To activate redundancy after replacing an SS7 card, send the CCS Redundancy Configure message using the same primary and secondary assignments for the SS7 cards as when redundancy was originally configured.

You must reconfigure signaling links and PPL configuration (PPL Assign, PPL Configure, and PPL Timer Configure messages) for link-related components. Link components are documented in the Chapter 7, SS7 PPL Information of this developer’s guide.

Querying Redundancy

You can query the redundancy information by sending the CCS Redundancy Query message. The CSP returns the state of the redundant pair and identifies the slots of the Primary, Secondary, and Active cards.

The following values are reported to the host in the CCS Redundancy Query message to indicate the redundancy status:

Synchronization States

0x01 | Primary Active, Secondary Synchronizing
0x02 | Secondary Active, Primary Synchronizing

Stable States

0x03 | Both Cards Active (Primary)
0x04 | Both Cards Active (Primary)

Redundancy Disabled

0x05 | Redundancy is being disabled

In-Service Upgrades

Making a Non-redundant System Redundant

To make a non-redundant system redundant, perform the following steps:

Step | Action
--- | ---
1 | Install a second SS7 card or an SS7 card and I/O card pair as shown in the CSP Hardware Installation and Maintenance Guide.
2 | Wait for system to send the Card Status Report message for each inserted card.
3 | Configure SS7 redundancy.
4 | Wait for synchronization to complete (Redundancy Status field value of 0x03 or 0x04 in the CCS Redundancy Report message).

Replacing an SS7 Card

To replace an SS7 card, perform the following steps:

Step | Action
--- | ---
1 | Press the STOP button on the SS7 card.
2 | Remove the appropriate SS7 card and replace it with a functional SS7 card.
3 | Wait for system to send the Card Status Report message for the inserted card.
4 | Configure SS7 redundancy. Configuring SS7 Card Redundancy
5 | Wait for synchronization to complete (Redundancy Status field value of 0x03 or 0x04 in the CCS Redundancy Report message).

Replacing an I/O Card

To replace an I/O card, perform the following steps:

Step | Action
--- | ---
1 | Press the STOP button of the SS7 card in front of the I/O cards.
2 | Remove the appropriate I/O card and replace it with a functional I/O card.
3 | Wait for system to send two Card Status Report messages, one for each of the I/O cards.
4 | Configure SS7 redundancy.
5 | Wait for synchronization to complete (Redundancy Status field value of 0x03 or 0x04 in the CCS Redundancy Report message).

See Signaling System Number Seven.
See Common Channel Signaling.
A computer, attached to the Excel platform through an RS-232 or Ethernet link, from which you run the telecommunications application that controls the Excel platform.
The condition of a component at a given instant. The current "context" of a PPL object, such as Idle, Seizing, Answered. In PPL files, a State is represented by a circle.
See Programmable Protocol Language.