What’s the difference between a network architect and a network designer? What is network architecture and what is network design? These are questions I asked myself a couple of years ago and that I get asked frequently from others. The reason I wanted to write this post is to help people that want to be network architects understand what it is about. I also wanted to help people that are studying for the CCDE to get into the right mindset. If you go in to the practical with the mindset of a designer, you will fail. You need to think like an architect.
This post is not about if an architect is more advanced than a designer. They are both needed and often they are the same person. I work as both but my title is network architect. Some people use the title to indicate it’s a senior role although the role might not be heavily geared towards design.
So what does a network architect do? And how is that different from the network designer?
The network architect is the one that is fronting the business. What does this mean? The network architect is the one that is meeting stakeholders such as the CIO, CTO, CSO, architects of the customer and other technical people and other key persons. The architect is interested in learning where the business is coming from and where they are going. What are the most important initiatives? Let me explain with a made up discussion.
CTO: We are spending way too much money on the WAN. Our WAN costs are 30% of our total IT spend.
Network architect: Have you analyzed what’s driving the cost for the WAN?
CTO: We are using a centralized internet model and 50% of our WAN cost is from backhauling internet traffic to the DC.
Network architect: In order to minimize the WAN costs, each site should implement a local internet breakout.
CSO: How will this affect our security model? Today all internet traffic is filtered at the firewall at the DC.
Network architect: There are several considerations here. It is possible to deploy local firewalls, use DNS filtering, client security, cloud proxies and so on.
What the network designer is thinking:
How to design the local breakout. How to ensure the local default route is better than the one over the WAN. How to perform NAT for the local subnets. How to setup GRE tunnels in case a cloud proxy is deployed.
CSO: We’ve had some security incidents recently where infected hosts in our office network have spread towards our servers in our production facilities. What should we do to prevent this from happening again?
Network architect: So today you have a flat topology where the office network can directly access the production network without any filtering, right?
CSO: That is correct.
Network architect: We must ensure that the office network can’t directly access the production network. This can be done by segmenting the network. Clients should have adequate protection. People that need access to the production network should use dedicated computers to access the production network. It would be desirable to implement a DMZ so that traffic into the production network goes through properly locked down jump hosts.
What the network designer is thinking:
How to segment the networks using VLANs and possibly VRFs. If and where firewalls should be deployed. Should they be in transparent or routed mode. What traffic should be allowed to the DMZ? How can endpoints be protected? What firewalls would be suitable to handle the amount of traffic in this network?
It should be clear based on the discussion above that the network architect is focusing on solutions, not products. The network designer will create the actual design and pick suitable products.
So what are the responsibilities of the architect? This is not an all inclusive list but here are some tasks the architect will perform:
- Fronting the business
- Gathering requirements
- Creating a high level design
- Presenting the design to the business
- Interacting with network designers
- Helping in writing business cases and other documents used to pick the direction going forward
In some projects I just act as the architect and in some projects I also act as the designer and do the detailed design with products, selecting the software, producing all of the configuration and so on.
I hope this post has given you an insight into what a network architect does and the mindset of the architect.