CloudNets S5 E4: Last Mile Redundancy Dilemma

Last Mile Redundancy Dilemma

In this episode, Dudy Cohen and Brad Riapolov dive into the last-mile redundancy dilemma for service providers. We explore the trade-offs between single and dual connections, the complexity of traditional chassis-based designs, and how Distributed Disaggregated Chassis (DDC) delivers the best of both worlds—true redundancy, resilience, and scalability without added operational complexity.

Chapters:

• 0:00 – Intro
• 00:26 – What are the considerations around Last Mile redundancy?
• 00:51 – What is the consideration about the node?
• 01:19 – Is there a way to make it simpler?
• 02:13 – Summary

Key Takeaways

• Last-mile redundancy is a cost vs. complexity trade-off
  Single-homed connections lack full control and data plane redundancy, while dual-homed connections improve resilience but significantly increase cost and operational complexity.
• Traditional chassis-based redundancy is hard to scale
  Relying on dual route processors, shared state, and complex configurations makes chassis-based designs difficult to operate and maintain—especially as networks grow.
• DDC enables true redundancy without operational overhead
  DriveNets’ Distributed Disaggregated Chassis combines the resilience of a chassis with the flexibility of fixed white-box systems, eliminating single points of failure while simplifying deployment and scaling.

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FAQs

• What is the main challenge with last-mile redundancy?

  Last-mile redundancy involves balancing resilience, cost, and complexity. Single connections lack full redundancy, while dual connections improve reliability but come with higher costs and more complex network designs.

• Why are traditional chassis-based solutions considered complex?

  Chassis-based designs require dual route processors, shared state synchronization, and advanced configurations, which increase operational complexity and make them harder to manage at scale.

• How does DriveNets DDC simplify last-mile redundancy?

  DDC uses fixed white-box elements to create a virtual chassis that delivers full control and data plane redundancy without single points of failure or complicated routing configurations.

• How can network design reduce blast radius?

  Blast radius can be reduced by splitting the network into smaller, isolated domains. Techniques include segmenting the network using routing protocols (such as IGP or BGP) or creating architectural “islands” that prevent failures from propagating beyond their local domain.

• How does a distributed chassis architecture reduce blast radius?

  In a distributed chassis, failures are isolated to individual elements rather than impacting the entire system. If a single box fails, only customers directly connected to that box are affected, while traffic for other customers is rerouted through redundant elements in the cluster.

Read the full transcript

Welcome to CloudNets where networks meet cloud and today we’re going to talk about the last mile redundancy dilemma and we have our last mile expert, Brad. Thank you for joining. Brad, when you come to connect business customers, usually you worry about the last mile redundancy.

What are the considerations around the last mile redundancy dilemma?
Well, many of our customers are considering whether to pull a single connection to the customer or maybe work with dual connection. Dual connections, Dual homing. Dual connections present their own problem because they’re twice the cost. The single home connections obviously lack the redundant data plane and control plane.

What is the consideration about the node that is connected to the customer?

You need a chassis.

Typically customers with a single home run to the customer rely on dual RPs or a chassis based model to be able to survive some sort of a bad event on the network. Right. So you need a dual RPs, you need some sort of a state that you keep between those RPs like SSUs what are getting more and more complicated. And so that’s a complex configuration for network and experts of any size and scale.

Is there a way to make it simpler?

Yes, there is. And we’ve seen a massive exit from many customers that are traditionally chassis have been used a traditionally chassis based approach to more of a fixed boxed approach. They do dual runs to the customer. Right. And they rely on some sort of IGP to be able to control that. I think in the case of DriveNets and what we bring to the table is the ability to take fixed elements, fixed white box elements and build a virtual chassis providing you both, AKA DDC.

Correct.

Providing you both the benefits of dual home runs to the customer. For redundancies, there’s no single element that is a single point of failure at the same time giving you the flexibility of that massively engineered control and data plane that is completely resilient, completely redundant.

Oh, that’s great. Again, enjoying the best of both worlds with DDC. So you can address the need of more and more customers that want a dual home to two different boxes in your central office. And on the other side you don’t need to deploy multiple, you know, standalone boxes and a tricky IGP configuration in order to make this redundancy happen. You can have DDC which has the features of a chassis, but the distribution and scalability and redundancy of this multiple boxes configuration. Thank you very much Brad for joining. Thank you for watching. See you next time on CloudNets.