Until recently, it was commonly believed that Wavelength Division Multiplexing (WDM) solutions used for building backbone networks were complex, expensive and that only big telecommunication companies could afford them. The fear that such solutions were too complicated to deploy, prevented a great number of data centres and ISP operators from deciding to use them.

There are two methods of building networks using WDM technology. The first, known as a passive solution, relies on “colourful optics” and is installed directly into existing network devices such as routers and switches. The other is an active solution in which we set up a clear demarcation, or border, between switches or routers and a WDM network. This border is made up of transponders and muxponders.

Active-vs-passive

Passive solutions help to satisfy the increasing need for broadband in a quick and economical way. However, their management can be difficult, particularly in relation to network expansion. This is due to the fact that the previously mentioned “colourful optics” are dispersed around the network and installed in a variety of devices. This makes diagnosing network problems very difficult. What’s more, until recently it was necessary for optical transceivers to be compatible with the devices in which they were installed, and this is still the case today. However, there is a device which helps to overcome this limitation – a Simple Recode Device (SRD) - more about this solution in our article: Does a universal optical module exist?).

Active solutions, on the other hand, allow us to set up a border between SAN/LAN and WDM networks. This enables us to provide services based on one’s own fibre resources and achieve a very high SLA. Moreover, due to the use of muxponders, active solutions deliver an optimal use of optical spectrum by combining several streams of low capacity and sending them via a WDM network in only one optical channel. This makes the management and maintenance of such a network much easier and is likely to lower operational costs.

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So, let’s sum up the most important features of passive solutions:

  • Dispersed management of optical layers
  • Limited possibilities to monitor efficiency and isolate failures
  • Low cost of deployment

The most important features of active solutions are:

  • Central management of an optical layer
  • Advanced monitoring and failure diagnostics
  • Optimum use of the optical spectrum
  • A distinct border between SAN/LAN and WDM networks

So, which solution to choose? Should you focus on low cost of deployment or go for an optimal use of spectrum and central management? The answer to these questions is not as easy as it may seem, and the choice will depend on a variety of factors. At Salumanus we treat every scenario individually and select solutions that best satisfy the requirements of our clients in the fast changing world of telecommunications.

Are you hesitating to decide which solution is better for you? Contact us and we will help you make the right decision and choose a solution that best suits your network. We are here to help you build leading telecommunication networks.

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