Chapter 3 Topology
Physical Topologies
Cisco SCE 2000 4xGBE Installation and Configuration Guide
OL-7824-04 3-9
• When one SCE 2000 fails (depending on the type of failure) its link traffic is still bypassed
to the functioning SCE 2000 and processed there, so the traffic processing continues for
both the links.
• The bypass of the traffic through the failed SCE 2000 is configurable, and the user may
choose to always cutoff the line that goes through the failed SCE 2000. In this case network
redundancy protocols like HSRP are responsible for identifying the line cutoff and
switching all the traffic to go through the functioning SCE 2000.
Refer to the following sections to determine the correct values for all topology-related parameters
before beginning run the initial setup of the SCE 2000.
SCE 2000 Configuration
There are four topology-related parameters:
• Connection mode — Can be any one of the following, depending on the physical
installation of the SCE 2000 (Refer to Connection Mode Parameter (on page 3-9)):
• Inline — single SCE 2000 inline
• Receive-only — single SCE 2000 receive-only
• Inline-cascade — two SCE 2000s inline
• Receive-only-cascade — two SCE 2000s receive-only
• Physically-connected-links — In cascaded configurations, this parameter defines the
number of the link connected to this SCE 2000 (Refer to Physically Connected Links
Parameter (on page 3-10)).
It is applicable only in a cascade topology.
• Priority — This parameter defines which is the primary SCE 2000 (Refer to Priority (on
page 3-10)).
It is applicable only in a cascade topology.
• On-failure — This parameter determines whether the system cuts the traffic or bypasses it
when the SCE 2000 either has failed or is booting. It is not applicable to receive-only
topologies (Refer to On-Failure Mode Parameter (on page 3-10)).
Any of these parameters may be configured via either the setup command or the
connection-mode command.
Connection Mode Parameter
The connection mode parameter refers directly to the physical topology in which the SCE 2000 is
installed. The connection mode depends on two factors:
• Inline/Receive-only:
• Inline — The SCE 2000 resides on the data link between the subscriber side and the
network side, thus both receiving and transmitting packets.