Cisco Systems SCE 1000 2xGBE Topology-Related Parameters, Redundancy, Connection Mode Parameter

Chapter 3 Topology

Topology-Related Parameters

Redundancy

Redundancy requires two platforms on parallel links, one active and one standby, in inline topology. When the active SCE 1000 platform detects a failure situation, it will immediately switch to Cutoff mode, causing the routers/switches on both ends to switch the traffic to the standby link and thus activate the standby SCE 1000 platform.

There are two options when the failed SCE 1000 platform is finished reloading:

•It may either actually resume operation in the defined operational bypass mode, returning to its status as the active SCE 1000 platform.

•It may remain inactive in the failure bypass mode.

Maintaining the Network Links vs Maintaining SCE 1000 Platform Functionality

When a single SCE 1000 is deployed, the user may decide that in case of a failure, maintaining the network link is more important than providing the SCE 1000 functionality. In this scenario, when the SCE 1000 detects a failure that requires a reboot process for recovering, it immediately switches to Bypass mode, allowing all traffic to bypass the SCE 1000. The SCE 1000 stays in Bypass mode maintaining the network link, albeit without SCE 1000 processing, until the SCE 1000 fully recovers from the failure and is ready to resume normal functioning.

Alternatively, the user may decide that the SCE 1000 functionality is sufficiently crucial to require severing the link if the SCE 1000 platform fails. In this case, when the SCE 1000 detects a failure that requires a reboot process for recovering, it immediately switches to Cutoff mode, stopping all traffic flow. The SCE 1000 stays in Cutoff mode, halting all traffic, until it fully recovers from the failure and is ready to resume normal functioning. In Cutoff the physical interface is blocked, enabling the network device connected to the SCE 1000 to sense that the link is down.

Topology-Related Parameters

Refer to the following sections to determine the correct values for all topology-related parameters before beginning run the initial setup of the SCE 1000.

Connection Mode Parameter

The connection mode parameter refers directly to the physical topology in which the SCE 1000 is installed. Installation is possible in either of the two following modes:

•Inline — The SCE 1000 resides on the data link between the subscriber side and the network side, thus both receiving and transmitting packets.

•Receive-only— The SCE 1000 does not reside physically on the data link. Data is forwarded to the SCE 1000 via an external optical splitter. The SCE 1000 itself receives only and does not transmit.

Note Default value = Inline

Cisco SCE 1000 2xGBE Installation and Configuration Guide

OL-7821-04 3-7