What are Disaggregated Networks?

Disaggregation is a term you will increasingly hear within telecommunications service providers and network equipment manufacturers. So, what is dis-aggregation? In short, it is a move by service providers to prevent “vendor lock-in”. Vendor lock-in can occur when an equipment manufacturer provides products and systems that have some degree of proprietary functionality. This makes it very difficult for customers to switch suppliers. This can be problematic as from time to time, equipment may be in short supply or simply does not function as well as expected. Another reason is that equipment manufacturers often exploit this lock-in for commercial advantage. For instance, the initial capital expense may be kept low, but some functionality is restricted. Manufacturers are then able to charge excessive prices for licenses to unlock additional functionality.

Disaggregation can take many forms and there are numerous industry initiatives that have the set objective of realizing disaggregation. Let’s take an example for a layer 1 optical system. Traditionally, you would go to a vendor to procure a system.That vendor will supply all components. The system would comprise a chassis,transponder cards, filters and amplifiers.

Traditional monolithic vendor architecture
A closed Proprietary System

The example above is one such system and in this case the management of that system is through the manufacturer’s own Network Management System (NMS). It’s fair to say that there are advantages to this approach and the relative Pros and Cons are discussed later in this article.

In a disaggregated system, each component can be supplied by a different vendor and all managed separately.  In the example below the system has the same functionality as the one above, but the components are sourced from different vendors. The NMS in this case is also vendor agnostic and built on open standards and may be open source.

disaggregated architecture
A Disaggregated System from Multiple Vendors

That’s one interpretation of what disaggregation is about. Another perspective is to look at what is happening at layer 2 and layer 3 of the network. Switching and routing are performed at layers 2 and layer 3 respectively. The traditional approach would be to take equipment from one or maybe two manufacturers. The manufacturers would undertake the equipment design and provide the hardware and software as one entity. Essentially, a monolithic product. What network operators are pushing for is what is termed “whitebox” hardware. A whitebox device is generic hardware platform optimized for networking. These can be manufactured as opensource hardware designs. There will be more on opensource hardware later in this article. What network operators will then do is to source the operating software from the traditional vendors. They are expected to supply their switching and routing products in the form of a software image that will run on that hardware. There are whitebox solutions that fit the CPE space and at the other end of the scale, 800Gbps capable core switching or datacenter edge solutions.

Open Source Hardware

Although not directly associated with disaggregation, but very much a complimentary area, is the concept of open source hardware. Open source hardware schematics are designed under an open, community-based project and the schematics offered freely for anybody to manufacture.  Many sponsors of such projects are not hardware manufacturers themselves but are organisations that aim to benefit from the disaggregation concepts. They will sponsor such developments to help drive change and disrupt traditional markets.

For a better understanding of such concepts, it is useful to study the work of the Telecom Infra Project or TIP https://telecominfraproject.com/. One TIP project has delivered an open-packet optical transport device. Facebook was a major contributor with the hardware design referred to as Voyager. Other companies have manufactured the hardware,developed software and provided support options. The Voyager platform is basically a disaggregated optical transponder that is managed independently of any filter or optical amplification components.

Facebook voyager
The TIP Voyager Platform

Pro and Cons of Disaggregation

So why would any vendors go down the disaggregation route? Let’s be clear there are quite a few reasons to go down the traditional route:

  • A solution from a single vendor is easier to support
  • Testing is easier
  • There is a single point of contact for all issues
  • Management and OSS integration should be easier
  • There are fewer test cycles needed
  • There are fewer decisions to make

All these factors are significant and imply that disaggregation is more expensive than the traditional network. This may well be true but vendor lock in can make a service provider feel vulnerable. Equipment may become end of life with no replacement. Innovation take a long time and the vendor may not deliver the functionality expected. Vendors may fall out of favor with governments as is the case with some Chinese manufacturers. A disaggregated solution may not appear to be more cost effective, but time to market is often much shorter and the service provider has choice.

Conclusion

In this article we have explored the concepts of disaggregation within service provider networks and the consequential changes in the way equipment manufacturers will have to design and deliver products.It’s too early to say whether disaggregation is fad, but there are real projects underway and disaggregated products are available on the market. So, it is prudent to be aware and keep an eye on this developing area.

To find out more about disaggregation look at the Telecom Infra Project website https://telecominfraproject.com/

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