Datasheet

11-2
Cisco ONS 15454 SDH Reference Manual, R7.0
October 2008
Chapter 11 Circuits and Tunnels
11.1 Overview
11.1 Overview
You can create circuits across and within ONS 15454 SDH nodes and assign different attributes to
circuits. For example, you can:
• Create one-way, two-way (bidirectional), or broadcast circuits. VC low-order path tunnels
(VC_LO_PATH_TUNNEL) are automatically set to bidirectional and do not use multiple drops.
• Assign user-defined names to circuits.
• Assign different circuit sizes.
• Enable port grouping on low-order path tunnels. Three ports form a port group. For example, in one
E3-12 or one DS3i-N-12 card, four port groups are available: Ports 1 to 3 = PG1, Ports 4 to 6 = PG2,
Ports 7 to 9 = PG3, and Ports 10 to 12 = PG4.
Note Monitor circuits cannot be created on a VC3 circuit in a port group.
• Automatically or manually route VC high-order and low-order path circuits.
• Automatically route VC low-order path tunnels.
• Automatically create multiple circuits with autoranging. VC low-order path tunnels do not use
autoranging.
• Provide full protection to the circuit path.
• Provide only protected sources and destinations for circuits.
• Define a secondary circuit source or destination that allows you to interoperate an ONS 15454 SDH
subnetwork connection protection (SNCP) ring with third-party equipment SNCPs.
You can provision circuits at any of the following points:
• Before cards are installed. The ONS 15454 SDH allows you to provision slots and circuits before
installing the traffic cards. However, circuits cannot carry traffic until you install the cards and place
their ports in service. For card installation procedures and ring-related procedures, refer to the
Cisco ONS 15454 SDH Procedure Guide.
• After cards are installed, but before their ports are in service (enabled). You must put the ports in
service before circuits can carry traffic.
• After you preprovision the small form-factor pluggables (SFPs) (also called pluggable port modules
[PPMs]).
• When cards and SFPs are installed and ports are enabled. Circuits do not actually carry traffic until
the cards and SFPs are installed and the ports are in the Unlocked-enabled state; the
Locked-enabled,maintenance state; or the Unlocked-disabled,automaticInService state. Circuits
carry traffic as soon as the signal is received.
11.2 Circuit Properties
The ONS 15454 SDH Circuits window, which appears in network, node, and card view, is where you can
view information about circuits. The Circuits window (Figure 11-1 on page 11-4) provides the following
information:
• Name—The name of the circuit. The circuit name can be manually assigned or automatically
generated.