Datasheet

Data Sheet

Protection Options

The Cisco ONS 15454 MSTP provides multiple provisionable interface protection options, which facilitate support for

high-availability as well as unprotected service delivery to meet the varied service-level agreements (SLAs) for

DWDM transport offerings.

Both 1+1 and Shared protection schemes based on the principles of ITU-T Recommendations can be supported.

The following types of 1+1 protection schemes can be supported:

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Path Protection

In this case it is possible to offer complete redundancy of the optical path at the network level but no

protection is offered for the unit which is originating the Working and the Protect DWDM signal and deciding

among the two DWDM signals on the receive side.

This type of protection can be supported on individual wavelengths by 2.5Gbps Transponder and Muxponder

units (leveraging on their Protected version); by the GE and the 10GE XPonder units (operating in Layer2

mode); by the MSPP-On-A-Blade unit; by the OTU2 XPonder unit; and by the Protection Switching Module

(PSM), when used in conjunction with unprotected Transponder or Muxponder units, or with an Alien DWDM

signal. PSM unit can be used to provide protection for the Multiplexed signal.

●

Path & Equipment Protection

In this case it is possible to offer complete redundancy of the optical path at the network level and of the units

which are originating the Working and the Protect DWDM signals and deciding among the two DWDM

signals on the receive side.

This type of protection can be supported by 2.5Gbps Transponder and Muxponder units (leveraging on their

Unprotected version); by 10Gbps Transponder and Muxponder units; by the GE and the 10GE XPonder units

(operating in Layer1 and Layer2 mode); by the OTU2 XPonder unit.

●

Multiplex Section Protection

In this case it is possible to leverage on the PSM unit to provide protection for the aggregated signal.

Shared protection can be supported by the GE and the 10GE XPonder units leveraging on the revolutionary GR3

Ethernet protection (Cisco patented G.709 Rapid Resilient Ring Ethernet Protection mechanism), when operating in

Layer2 mode. By integrating G.709 messaging with a Ethernet VLAN management mechanism, GR3 protection

provides SONET/SDH-like switching times and reliability. A recovery time of less then 50ms can be achieved

mapping Ethernet directly over DWDM.

Different units can support different protection options and feature different capabilities which are deeper described

in the unit datasheet.

Topology Flexibility

One recent core network trend is the consolidation of multiple Layer 2/3 networks into a single IP/Multiprotocol Label

Switching (IP/MPLS) infrastructure. In spite of this Layer 2/3 convergence, however, the underlying transport layer

(Layer 1) of many service provider core networks has continued to use SONET/SDH. This has remained largely the

case in many service provider networks globally today, creating OpEx and CapEx concerns for service providers as

well as the challenges of profitability and return on investment. Some network inefficiencies result from the way core

transport networks are built out today to support the IP or Service layer over the SONET/SDH layer, supported by an

underlying DWDM infrastructure. The OEO conversions and the associated electrical processing driven by the

layered network architecture result in an additional cost in terms of space, because many racks of shelves may be

required in a service provider POP, as well as additional power and cooling that is necessary because of the active

electronics components that they contain.