Vcat; Table 5-1 Sonet Sts Circuit Capacity In Line Rate Mbps - Cisco ONS 15454 SDH Configuration Manual

VCAT

Both SONET and SDH have a hierarchy of signaling speeds. Multiple lower level signals can be
multiplexed together to form higher level signals. For example, three STS-1 signals can be multiplexed
together to form a STS-3 signal, and four STM-1 signals can be multiplexed together to form a STM-4
signal.
SONET circuit sizes are defined as STS-n, where n is a multiple of 51.84 Mbps and n is equal to or
greater than 1. SDH circuit sizes are defined as STM-n, where n is a multiple of 155.52 Mbps and n is
equal to or greater than 0.
Table 5-1
SONET Circuit Size
STS-1 (OC-1)
STS-3c (OC-3)
STS-6c (OC-6)
STS-9c (OC-9)
STS-12c (OC-12)
STS-24c (OC-24)
1. VC-3 circuit support requires an XC-VXx or XC-VCX-10G card to be installed.
For step-by-step instructions on configuring an ML-Series card SONET STS circuit, refer to the "Create
Circuits and VT Tunnels" chapter of the Cisco ONS 15454 Procedure Guide. For step-by-step
instructions on configuring an ML-Series card SDH STM circuit, refer to the "Create Circuits and
Tunnels" chapter of the Cisco ONS 15454 SDH Procedure Guide.
VCAT
VCAT significantly improves the efficiency of data transport over SONET/SDH by grouping the
synchronous payload envelopes (SPEs) of SONET/SDH frames in a nonconsecutive manner into VCAT
groups. VCAT group circuit bandwidth is divided into smaller circuits called VCAT members. The
individual members act as independent circuits.
Intermediate nodes treat the VCAT members as normal circuits that are independently routed and
protected by the SONET/SDH network. At the terminating nodes, these member circuits are multiplexed
into a contiguous stream of data. VCAT avoids the SONET/SDH bandwidth fragmentation problem and
allows finer granularity for provisioning of bandwidth services.
The ONS 15454 SONET and ONS 15454 SDH ML-Series card VCAT circuits must also be routed over
common fiber and be both bidirectional and symmetric. Only high order (HO) VCAT circuits are
supported. The ML-Series card supports a maximum of two VCAT groups, with each group
corresponding to one of the POS ports. Each VCAT group can contain two circuit members. A VCAT
circuit originating from an ML-Series card must terminate on another ML-Series card or a CE-Series
card.
Cisco ONS 15454 and Cisco ONS 15454 SDH Ethernet Card Software Feature and Configuration Guide, R8.0
5-2
Table 5-1
SONET STS Circuit Capacity in Line Rate Mbps
SDH Circuit Size
1
VC-3
STM-1 (VC4)
STM-2 (VC4-2c)
STM-3 (VC4-3c)
STM-4 (VC4-4c)
STM-8 (VC4-8c)
Table 5-2 shows supported VCAT circuit sizes for the ML-Series.
shows STS and STM line rate equivalents.
Line Rate in Mbps
52 Mbps
156 Mbps
311 Mbps
466 Mbps
622 Mbps
1244 Mbps (1.24 Gbps)
Chapter 5 Configuring POS