Under pressure to deliver greater bandwidth to customers, service providers are trying to figure out how to get more from their existing bandwidth. Their high-capacity optical transport networks already are experiencing strain under the escalating request for services at higher rates up to 10 gigabit. To help meet this demand, service providers are looking to pack wavelengths with as much traffic as possible.
In todays session, Expanding the Bandwidth Pipe: Subwave Technologies, at COMPTEL PLUS in Las Vegas, panelists will discuss how service providers can optimize the use of their optical transport networks by using WDM as a foundational layer and Ethernet as a client interface for next-generation services as well as SONET/SDH as a client interface for legacy services.
Transport architectures need to transition to provide long-term scalability and flexibility required to support next-generation services while maintaining the key attributes of SLA guarantees and OAM simplicity, said panelist Ken Davison, vice president of marketing and business development for Meriton Networks.
Most importantly, the new transport network must provide a clear separation between the transport and service layers within a [next-generation network], he argued. Davison will be championing a new market category he calls Carrier Ethernet Transport (CET). This is in contrast to carrier Ethernet services defined by the Metro Ethernet Forum, like E-line and E-LAN.
CET enhances WDM/OTN to enable end-to-end networking of wavelengths with subwavelength (GigEs) switching, and then integrates Ethernet Tunnel Switching (PBT or T-MPLS) to provide a truly innovative approach, he said.
By separating the optical and service layers, CET pushes only terminating traffic into the service layer instead of traffic that needs to be switched. The resulting architecture gives carriers a cost-effective switched architecture with three levels of switching granularity (wavelength, subwavelength and sub-subwavelength, or tunnel switching). Its a transport architecture that is much better aligned to the NGN services it will be carrying.
Panelist Emanuel Nachum, vice president of marketing and business development for optical gear vendor ECI Telecom, also will talk about advances in optical networking using multidegree, reconfigurable optical ADMs that allow service providers to integrate Ethernet, SONET and SAN services in the same platform in a cost-effective way.
The issue [with ROADM] in the past was the cost, but the technology is maturing. A complete reconfigurable tunable optical solution is affordable today, he said, noting its nearing the cost of fixed OADMs but adding additional benefits, like time-to-market and any-to-any service delivery that impact total cost of ownership. Very quickly after a few wavelengths the tunable, reconfigurable network is more cost-effective.
In addition to a multiwavelength solution, carriers can look to subwave grooming to deliver Ethernet, SONET and low-rate services on a single wavelength. Basically, we offer any-to-any [connections] at the electrical or optical domain. Once you do it in the electrical domain, you can pack multiple services into a single wavelength. I will be talking about both options, he said. It really depends on what services you have to deliver.
Where customers require low-rate, subwave services, a ROADM-ready WDM system can be used to deliver a single wavelength solution while able to accommodate high bit rate services when demand arises. In some other cases, you can start from the other way around, he added. You can have demand for gigE or 10gigE or optical storage. You can start by putting the optical layer to deliver these services and add the low-rate and subwave services as needed.
Panelist Umesh Kukreja, director of product marketing for Ethernet gear vendor Atrica Inc., said carrier Ethernet is one transport option that competitive service providers can use to deliver high-bandwidth Ethernet services with the assurance that they will have the ability to smoothly scale their networks from 10 to 40 to 100 gigabits as their bandwidth needs grow.
He said in his experiences with service providers, delivering the bandwidth is only part of the equation. If you deliver bandwidth to an end user, the next step from a differentiation perspective is to really define the SLAs around that bandwidth, he said, explaining the need to apply classes of service to the products. In order to deliver the SLAs, you have to implement an Ethernet transport infrastructure combined with an optical transport infrastructure.
Atrica Inc. www.atrica.com
ECI Telecom Ltd. www.ecitele.com
Meriton Networks www.meriton.com