Configuring LOS Detection on CTP and SAToP Bundles (CTP Menu)

Starting with CTPOS Release 7.2R1, CTP devices support the detection of a loss of signal, which denotes a physical link problem. The following conditions are supported:

In a serial both-ended Y-cable redundancy configuration (hardware-based redundancy or software-based Y cable link protocol), removal of Y cable leg from the CTP port of the online bundle must be able to force a switch to the standby bundle.
In a T1/E1 both-ended Y cable configuration (hardware-based redundancy or software-based Y cable link protocol), removal of Y cable leg from the CTP port of the online bundle must be able to force a switch to the standby bundle.

A CTP series device provides two types of Y-cable redundancy.

Redundancy by using a hardware link that uses a special Y cable
Redundancy by using a software link that does not depend on a signaling hardware like the Y cable

The CTP devices support a both-ended redundancy mechanism, in which two identical CTP circuit bundles are combined using Y cables at each end, enabling one bundle to act as a backup for the other. One of the bundles is in use (online), while the other is in the standby state (offline). Only the online bundle is allowed to drive the Y cable towards the user equipment, while the offline bundle is tristate. A communications channel (such as redundancy by using a hardware link that uses a special Y cable or redundancy based on a software link that does not depend on a signaling hardware like the Y cable) between ports at each end determines which of the two ports on the Y cable is currently online. When one bundle fails, the failed bundle transitions to the offline and places the other bundle in the online state.

Before you begin:

Disable the bundle before you modify the bundle options.

To configure the capability to detect LOS alarms in a Y-cable redundancy configuration for CTP and SAToP bundles by using the CTP Menu:

From the Main Menu, select 1) Bundle Operations.
Select 1) CTP.
Select a bundle from the list.
If you select an active bundle, you are prompted to disable the bundle before configuring it.
Select 3) Port Config.
Select 4) Advanced Options to configure advanced attributed for the CTP bundle.
Select 20) LOS checking (T1E1 only) to configure the functionality to detect LOS for the T1E! interfaces in a CTP bundle or SAToP bundle.
Follow the onscreen instructions and configure the options as described Table 16.

Table 16: LOS Settings in the CTP Menu

Field	Function	Your Action
Check LOS on T1/E1 ports for CTP/SAToP bundles? y[n]	Specifies that the capability to identify LOS alarms on T1E1 interfaces in SAToP or CTP bundles needs to be enabled. A loss of signal (LOS) alarm indicates that there is a physical link problem with the connection to the router receive port from the neighboring SONET equipment transmit port. An LOS alarm occurs when the port on the card is in service but no signal is being received. The cabling is not correctly connected to the ports, or no signal exists on the line. Possible causes for a loss of signal include upstream equipment failure or a fiber cut.	Enter y or n to enable or disable the LOS detection capability. Note: Although this menu option to enable or disable the LOS detection functionality is shown regardless of the port type, such as serial interfaces or T1E1 interfaces, this setting becomes effective on a T1/E1 port only when it is connected to a CTP or SAToP bundle. If the LOS detection functionality is enabled on a serial port or other bundle types, the setting is not processed.

Field

Function

Your Action

Check LOS on T1/E1 ports for CTP/SAToP bundles? y[n]

Specifies that the capability to identify LOS alarms on T1E1 interfaces in SAToP or CTP bundles needs to be enabled.

A loss of signal (LOS) alarm indicates that there is a physical link problem with the connection to the router receive port from the neighboring SONET equipment transmit port. An LOS alarm occurs when the port on the card is in service but no signal is being received. The cabling is not correctly connected to the ports, or no signal exists on the line. Possible causes for a loss of signal include upstream equipment failure or a fiber cut.

Enter y or n to enable or disable the LOS detection capability.

Note: Although this menu option to enable or disable the LOS detection functionality is shown regardless of the port type, such as serial interfaces or T1E1 interfaces, this setting becomes effective on a T1/E1 port only when it is connected to a CTP or SAToP bundle. If the LOS detection functionality is enabled on a serial port or other bundle types, the setting is not processed.