SC APS

Overview

1+1 APS can be implemented on a port-by-port basis. If all ports on an MDA or IOM need to be protected, the ports must be individually configured.

The working and protection lines are capable of being connected to:

• two ports on the same MDA (not applicable to the 7705 SAR)

• two ports on different MDAs, and the MDAs are on the same IOM

• two ports on different MDAs on different IOMs

If the working channel and protection channel are on the same MDA, protection is limited to the physical port and the media that connect the two NEs. If different IOMs are used, protection extends to failure of each IOM.

Note: The working and protection channels should be configured on different MDAs but on the same IOM card for the 7705 SAR-8 and 7705 SAR-18.

Working and protection lines can be connected to a 7705 SAR-8, 7705 SAR-8v2, 7705 SAR-18, 7450 ESS, or 7750 SR, and serve as an access port that provides one or more services to the NE. The access port can be a single channel or multiple channels; each channel must support PPP. In the case of the ATM MDA, each channel must support ATM.

The end NE transmits a valid data signal to both the working and protection lines. The signal on the protection line is ignored until the working channel fails or degrades to the degree that requires a switchover to the protection channel. When the switchover occurs, all services, including all service QoS and filter policies, are activated on the protection channel.

The working channel on a 7705 SAR-8, 7705 SAR-8v2, 7705 SAR-18, 7750 SR, or 7450 ESS must connect to the working channel on a peer NE, and the protection channel on a 7705 SAR-8, 7705 SAR-8v2, 7705 SAR-18, 7750 SR, or7450 ESS must connect to the protection channel on a peer NE.

1+1 optimized

You can configure an SC APS group with a 1+1 optimized configuration. A 1+1 optimized APS group is optimized for networks which rely primarily on 1+1 bidirectional switching. A 1+1 optimized APS group is configured with two working channels, as opposed to one working channel and one protection channel. In a 1+1 optimized configuration, one working channel acts as the primary channel, through which the traffic will always default. A 1+1 optimized APS group always operates in bidirectional and nonrevertive modes.