DDC Cable Management: Best Practices

What’s the problem with cable management?

When connecting a network device like a router that consists of hundreds of interfaces, you need to be sure that every cable is connected properly. This refers to the physical insertion of the cable and the space required to bend outbound in a way that avoids over angling it beyond its bend radius. It also refers to the logical soundness that the cable is indeed inserted to the correct cage.

The task of cabling such a router has three stages – planning, connecting, and maintaining. Good planning leads to easier implementation and maintenance so this is where most of our focus will reside. Aspects that should be taken into consideration are cable length and type, order of connectivity, labeling of the cables, and trays and ties as physical restraints to avoid dangling cables.

A large chassis has all of its connectivity handled within the boundaries of the chassis itself via traces and backplane connectors, which are all hidden from the user. While this is pleasing to the eye, it also hides a lot of potential problems and turns the router into a black box – but this is a topic for a different blog post.

A network cloud cluster has the architecture of a distributed chassis. In Distributed Disaggregated Chassis (DDC) implementations using DriveNets Network Cloud, the NCP (Network Cloud Packet Forwarder) acts as line cards, the NCF (Network Cloud Fabric) as fabric cards, and the NCM (Network Cloud Management) as the chassis’ management plane. These components are all connected via “internal” cables; this is in addition to the already large amount of cables facing the network, or “external” cables.

So there is more to do with a DriveNets Network Cloud DDC cluster in terms of cable handling than with a traditional chassis. Let’s see how to make this task easier and less prone to errors.

Tips and pointers for cable management

• Relax – this is only a one-time thing at the birth of a cluster and it’s easier with proper planning and tools

• Position the boxes in their targeted location **

• Start with cabling the management plane and verify it to work before moving to the data plane – this will ensure that the DriveNets Network Orchestrator (DNOR) will assist you in the next stages

• Define your cluster scale and follow the connectivity guidelines from DNOR **

• Next connect the fabric interfaces

• Note the length of each cable and label all cables as per your common practice

• Connect them all and align cables into trays and banded with ties

• Check DNOR for validity of the connection **

• Make fixes according to DNOR guideline using show system backplane command **

• Proceed to network interfaces

• Last general tip – regardless of which devices you install, use console cables

X factor for cable management

You noticed some of the tips above are marked with ** and are probably wondering what it means. A distributed chassis carries more cables than a traditional vertically integrated monolith, so it will take longer to connect all the pieces together and get it going. The ** items are where the end result is better than what you get from a traditional chassis.

Positioning every NCP and NCF in a flexible manner allows better usage of space in your facility and better distribution of the cable load. Trays can be inserted between boxes to improve their longevity and simplify maintenance tasks. The fact that the “internal” connectivity is done by actual cables, mean that you can monitor it and debug it upon need – no more “black box” routers.

Lastly, the fact that the system was built around manual connectivity done on-site motivated us to develop the DNOR platform; DNOR is the invaluable assistant that makes sure we make no mistakes (but alerts us if we do).

Cable Management with DDC

Don’t let cable handling steer you away from the powerful innovation granted by DDC solutions. When done right, it’s done better.