Datasheet

Data Sheet

by the GE and the 10GE XPonder units (operating in Layer1 and Layer2 mode); by the

OTU2 XPonder unit.

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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.

The Cisco ONS 15454 MSTP can be configured to support any metro, regional or core DWDM

topology, allowing a single solution to be used for the overall network, independently from the

topology and reach. The ultimate topology flexibility is achieved through a set of fully

reconfigurable optical add/drop multiplexer (ROADM). Multi-degree ROADMs (2 through 8 degrees

of freedom) allow wavelengths to remain in the optical domain while being passed from one ring or

network segment to another, further eliminating the need for OEO conversions and leveraging the

ability of core routers to initiate DWDM-compatible wavelengths (Figure 2).

Figure 2. Cisco Next Generation network strategy