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Interview with Ofer Finkelstein - Director, Business Development & Marketing EMEA

Q. Carriers, service providers and enterprises with significant investments in legacy infrastructure are increasingly looking for solutions that will allow them to migrate their circuit-switched voice services to emerging packet-based networks. What are their options? A. While Voice over IP is certainly one of the predominant technologies for achieving this purpose, it represents a costly approach which requires that existing TDM infrastructure be thrown out and replaced with all new systems.

Q. What is CES and what are its advantages?

A. CES is basically a technology that allows a TDM circuit, such as E1, T1, fractional E1 and T1, E3, T3, STM-1 and OC3, to be tunneled through a packet-switched network (PSN). 

Ethernet, MPLS and IP are changing the economics of data services delivery, bringing simplicity with lower cost to both carrier and enterprise users. CES takes advantage of this infrastructure to help carriers deliver high revenue leased line services in parallel to new Ethernet-based services.

CES enables service providers to migrate to packet-switched networks while continuing to provide all their revenue-generating legacy voice and data services. CES also benefits data carriers by enabling them to offer lucrative leased line and private line services. This lets them maximize revenues from their packet-switched infrastructure by selling voice services as well as data.

Q. Who benefits from CES?

A. Both telcos and cable operators can generate new revenue by delivering leased and private line services over their more scalable fiber Ethernet and HFC cable networks. We are also seeing increasing interest among cellular operations to reduce their leased line expenses by backhauling to Ethernet.

But CES isn’t just a carrier technology. Utility companies can reduce expenses and simplify their networks by migrating legacy voice and SCADA applications over Ethernet.

Q. What types of networks are most suitable for CES?

A. CES over Carrier Ethernet enables operators to rapidly build out Carrier Ethernet networks using high performance packet switches and routers, while continuing to deliver carrier-grade commercial TDM services.
CES over DOCSIS Cable allows MSOs to leverage their DOCSIS-based cable infrastructure to deliver lucrative commercial T1/E1-based voice and data services to small to medium-sized businesses.
CES over PON offers service providers the ability to bundle triple play services with commercial TDM services.
CES over Wireless delivers high quality, high capacity wireless TDM voice services utilizing enterprise or carrier core network equipment that extends beyond the reach of wired media.

Q. What are some of the challenges that the packet network has with transporting voice?

A. The biggest challenges are probably timing and synchronization, especially in the mobile wireless backhaul market. Base stations get their timing reference from the T1/E1 links, but when these are replaced by Ethernet, the frequency source is lost. Recently the ITU and IEEE have implemented standards to address the timing and synchronization issues. 

The IEEE 1588-2008 Precision Time Protocol employs a two-way methodology which sends packets back and forth from the clock master to the clock slaves. The method is an improvement on the adaptive clocking because it distributes a precise network clock to every node in the system.  The 1588-2008 protocol was extensively tested during this year’s EANTC interoperability event in conjunction with the Carrier Ethernet World Congress. You can download the white paper that details the testing at the EANTC web site.

The ITU has released G.8262 (also known as Synch-E) which is an end to-end frequency delivery method that preserves physical layer (Layer 1) synchronization  over Ethernet.  Higher layers can maintain their asynchronous status without affecting the way data is managed and switched.

Q. What solutions can Telco Systems offer in this market?

A. Telco Systems implements CES technology developed by Resolute Networks in both the T-Marc 254 and T-Metro product lines to deliver solutions that are fully compliant with IETF PWE3 (CESoPSN/SAToP), MEF-8, MEF-18, MFA-8.0.0, ITU Y.1413 and RoHS standards and protocols. We will be introducing CES-enabled devices that will be hardened for use in cellular backhaul environments soon.

Resolute Networks, a sister BATM company, is a leading developer of synchronous pseudowire and circuit emulation technology with a broad range of standards-compliant CES subsystem and OEM solutions. Their comprehensive line of CMX modules supports all common interfaces, synchronization requirements (G.823/G.824) and timing modes A future proof design is assured through their module-to-chipset cost reduction roadmap, scalable interface density and field upgrades to such new features and functions as integrated IEEE-1588 and Synch-E support.

If you would like additional information about CES, download our white paper, Ten Questions to Ask before Implementing Circuit Emulation Services over Packet Switched Networks.