Summary
The tremendous growth of IP traffic represents some exciting new revenue opportunities for service providers worldwide, but places significant capital and operational strains on networks carrying those services. As a result, many transport networks must transition from circuit- to packet-optimized architectures. Service providers — already having made significant investments in service edge and core networks using IP/Multi-Protocol Label Switching (IP/MPLS) routing equipment to support IP and Virtual Private LAN Services (VPLS) — are now focusing on the access and metro networks. Ethernet has emerged as the leading technology to support this evolution.
Analysis
The global growth of IP traffic in residential, business, and wireless networks is changing approaches to network building and service delivery. Anticipated bandwidth demands for services such as IP video, multimedia messaging, Internet access, and corporate data connectivity are expected to exceed 23,000 petabytes (petabytes = 1015 bytes) per monthby 2010, with a roughly 35 percent Compound Annual Growth Rate (CAGR) from 2006 to 2010. Today's transport SONET/SDH-based networks are incapable of handling those capacities, and Layer 3-centric, distributed IP router approaches are too expensive to use only for transport and aggregation when routing is not necessary.
Some market factors driving the evolution from TDM to apacket-centric transport network infrastructure include:
* Expectations that Ethernet/IP traffic will overtakeTDM traffic as the majority between 2008 and 2009
* Prevalence of IP/Ethernet in nearly all new deployedservices, including IP video, Voice over IP (VoIP), highspeed residential and commercial Internet access,Layer 2/3 business Virtual Private Networks (VPNs),and 3G/4G mobile wireless
* Lack of economical bandwidth scalability in SONET/SDH transport networks beyond 10G
* Packet-friendly nature of Ethernet as a transporttechnology and a service delivery vehicle for IP
At the service edge and in the core of the network, manyservice providers have deployed an IP-optimized infrastructure already, using IP/MPLS routers with an underlay DWDM or SONET/SDH transport layer. However, access and metro networks, not built with this same architecture, are still largely TDM-based. A router-centric metro architecture that provides connectivity from the service edge to the end-office is difficult to justify, because traffic patterns and service requirements require a more economical, manageable, and deterministic solution.
Ethernet has emerged as the leading technology on whichmany next-generation networks will be based, for economic and scalable transport and delivery of fast-growing, highbandwidth, IP-based applications. As use of Ethernet increases in the carrier domain as a transport technology — not just a service offering or protocol type — packet optical networking platforms have been developed to enable high-performance, connection-oriented, converged Ethernet transport networks.
These solutions allow service providers to build nextgeneration, packet-optimized network infrastructures in a cost-effective, deterministic, reliable, and manageable manner. A packet optical networking platform combines Layer 2 Ethernet intelligence with Layer 0/1 Optical Transport Network (OTN)/DWDM transport.
Alternative solutions include standalone Ethernetswitches with Dense Wavelength Division Multiplexing (DWDM) systems, next-generation SONET/SDH Multiservice Provisioning Platforms (MSPPs), and IP routers with a standalone optical transport layer. However, no alternative provides the balance of high-performance, economics, manageability, and flexibility found in a packet optical networking solution.
As a transport technology, Ethernet's lower cost andcomplexity hold more significant appeal in the access and metro portions of the network than Layer 3 switching, due to a host of Layer 3 issues such as IP address limitations, Dynamic Host Configuration Protocol (DHCP), Open Shortest Path First (OSPF), and multicast. A converged Ethernet transport architecture can optimize a metro network for future IP and Ethernet growth requirements to support traditional, non-IP services effectively.
By adding Layer 2 Ethernet intelligence to a DWDM/OTNtransport platform, providers can architect next-generation networks and provide efficient, flexible, high-performance backhaul to the IP service edge and core. This approach also allows network elements to be consolidated for more efficient use of existing transport, switching, and routing resources.
As Ethernet has moved into the metro transport domain,packet optical networking platforms have emerged. Theseplatforms enable converged Ethernet transport networks to address forecasted IP and Ethernet traffic demands while making more efficient use of service edge and coreIP router investments. In addition, the platforms cansupport traditional non-packet service requirementswhere necessary, simplifying the network, lowering costs, and providing a deterministic, packet-optimized infrastructure.
