If you’re like many government bodies, you probably have a lot of Time Division Multiplexing (TDM) technology in your infrastructure. That is not uncommon, but it can be a significant strain on resources because of the age of the equipment. The oldest of the TDM technologies are synchronous optical networking (SONET) and synchronous digital hierarchy (SDH), which had their origins in the late 1980s and came to market in the early 1990s.

Since then, TDM has formed the core of many government networks—even as more modern network technologies came on the scene. In my experience, the critical nature of the TDM applications meant some operations took an “if it ain’t broke don’t fix it” approach. But in recent years, that thinking has given way to a realization that the benefits of modern network architectures are too great to defer, and it’s time to tackle the TDM problem.

As a result, a growing number of organizations have been looking to move from TDM to packet-based technologies. The question is, though, how can you do it carefully, deliberately, and without affecting critical applications that won’t immediately move from TDM? Moreover, how can a government operation do it in a budget-friendly way?

To address these questions, Ciena’s TDM Migration Service provides both the technology foundation as well as the tools state, county, and local government bodies to upgrade their TDM networks at a pace that suits them. These solutions, which bridge the gap between TDM and modern networking, are engineered to industry & DoD best practices and are certified JITC and Common Criteria compliant.


What Are You Facing?

Many government networks run plain old telephone service (POTS) on plesiochronous digital hierarchy (PDH), which enables circuit-switched digital transmissions on copper. PDH utilizes a couple of different low-speed TDM-based transmission rates, which then get multiplexed into higher-speed fiber. Some government operations haven’t upgraded to digital telephony, so PDH was a way to bridge the analog-digital divide. In addition to POTS, those legacy networks might also connect to sensors, computers, and devices that have been running on TDM for more than 20 years.

Many manufacturers have discontinued SONET and SDH equipment, there’s little-to-no gear available, and the pool of expertise has dwindled to a precious few. The price tag for upgrading all the legacy equipment in short order is too high, and running two parallel sets of infrastructure is cost-prohibitive as well—plus it would be a maintenance headache. So governments are looking for a way to evolve their current infrastructure from these older networking technologies while preserving some of their TDM gear as they start their journey.

Faced with siloed operations and an avalanche of data that’s growing exponentially, governments really need a modern, packet-based network infrastructure that can bring the disparate legacy and modern elements together in a solution engineered for the specialized nature of government and defense applications.

How We Work with Governments

Ciena has significant experience working with government organizations to evolve their networks to keep the mission-critical TDM in place as they modernize their overall network infrastructure. Although no two government engagements are alike, there are a couple of common applications.

The first is something similar to a government equivalent of a carrier, which could be an organization like the Defense Information Systems Agency (DISA). Such an agency could use Ciena’s larger circuit-emulation solutions, like the 6500 Packet Transport System (PTS), to aggregate hundreds of SONET/SDH circuits. Seamless interoperability allows the replacement of one or more older Add/Drop Multiplexers (ADM) while still providing backwards compatibility with any remaining ADM’s and providing a path towards incremental packet growth. This can be done in multiple locations and geographies while providing connectivity to the more modern packet-switched network.

For complex migrations like this, Ciena’s TDM Migration Service can help by doing the legwork of identifying the circuits and provisioning them across the network. Our five-step modernization methodology lays the foundation, investigates the current network situation, plans the migration, executes it, and ensures all issues are closed upon completion.

On the other end of the spectrum, smaller-scale applications include internal connections for military bases, smaller government bodies, or satellite offices. We offer small network elements that can fit in almost any location with ports configured for DS1 – OC48 or Ethernet, which uses optical plug-ins. These require fewer circuits and provisioning, so the government organizations network management can often handle the migration themselves.

Ciena has a range of solutions for TDM-to-packet migration, including TDM SFPs, TDM service modules, and the 6500 PTS. Combined with management, analytics, and orchestration from Ciena’s Blue Planet suite of tools, we offer an open and extensible architecture for end-to-end lifecycle management and operations. Ciena has all the elements government operations need to build converged networks that streamline the migration and modernization process for edge, access, and metro aggregation sites.

Converging to Adaptive IP™

A while back, we introduced our Adaptive IP™ solution, based on our Adaptive Network™ vision to help government bodies make their networks simpler and more cost-effective by leveraging automation, openness, and simplicity for TDM, mobile, and L2/L3/VNF business services. Based on a streamlined, modular, open, and highly programmable IP architecture, Ciena’s service-aware operating system (SAOS) empowers government bodies to migrate legacy TDM services to a next-generation packet-optical network that uses MPLS and Ethernet switching techniques and advanced routing capabilities as a foundation for future IP services.

A Bridge to the Adaptive Network™

Migrating from TDM to packet opens you up to a smarter, more agile network—and a more innovation-ready infrastructure that responds when needed. As such, a TDM-to-packet migration puts you on the road toward Ciena’s Adaptive Network, which utilizes a unique combination of automation and analytics. Built on a programmable infrastructure, the Adaptive Network rapidly scales, self-configures, and self-optimizes by continually assessing network pressures.

Every decade or so, there’s talk about how long TDM technologies will be with us. My feeling is that it will disappear at some point. But I’d wager that a decade from now, we’ll still have lots of this technology in use around the world.

With solutions from Ciena bridging the divide, that won’t be a problem.