Three Types of Networks – Choosing a Career Path

I am going to do something annoying: I am going to classify computer networks into three broad types and discuss the differences. You may rest easy however, knowing I will not take the cliche next step of creating a social hierarchy based on this analysis. I’m sure there are other ways to slice ‘n’ dice types of networks and plenty of sub-types, but in my career these distinctions have really stood out as relevant to a network engineer’s career path. I have no experience in university networks, so I’m pretending they don’t exist.

The corporate network is the most ubiquitous. This network is characterized by several features:

  • User interaction. Here is where you are going to interface directly with your customers (aka users). They will lean over the cube wall if their web sites load slowly, their phone doesn’t work, or any number of things that may or may not be in your playpen.
  • Chaos. There is a great chance you will have a group of switching closets all connected back to a small data center (DC). The key to appreciating this data center is realizing that unlike many environments in other types of networks, in this DC every rack is different. While this can happen elsewhere, it is all but guaranteed in the corporate network world. You will probably also have to deal with fairly lax physical access controls to the DC, leading to what any self-respecting, OCD neteng would label an unholy mess.
  • User-facing technology. Here is where you deal with VOIP, 802.1x, wireless, and other technology that affects users directly.

Content networks are about pushing gigabits, pure and simple. Any Content Distribution Network (CDN) will be here, and to a large degree the massive sites like Facebook (and my alma mater Myspace in its heyday) fit here too. While the business model is more complicated than “me deliver bits, ugh,” the network is set up do that above all else. This type of network has a good future with the current cloud craze. Here’s what you will see in a content network:

  • Fat pipes. While content networks vary in size, you can expect to see multiple 10Gb interfaces per site, with annoyed foot-tapping from geeks and management alike while you wait for 100Gb cards to filter out into the world.
  • Scalability issues. As implied by the last point, many if not most of the problems you will be solving in a content network will surround scaling the network as fast and sanely as possible.
  • Simplicity…of sorts. Because of the scaling problems and relative abstraction from end users, you can expect to roll out 10 or more racks of identical hardware at once.
  • Multiple providers and peers. Since your primary task is to shoot bits across the globe, you will find yourself peering with as many companies as possible with little concern for business goals or strategy. Officially, this is called an “open” peering policy; essentially, it means you say “yes” to anyone and solicit everyone you can without being rude or annoying. You will also be one of those complicated BGP use cases you probably read about as a CCNA/P trainee, splitting outbound traffic between various providers based on latency, cost, politics, and other factors. (As a corollary to this point, expect to spend a lot of time troubleshooting the internet and shifting traffic around.)

I deliberately avoided the term “ISP,” because nowadays your ISP also provides more than the “I.” It provides whatever it thinks it can make a profit on. These are your telcos (telephone companies) like AT&T, cable TV/internet players like Cox Cable, regional carriers like PCCW, and little guys with plenty of big-ish players like Hurricane Electric in there. Provider networks entail:

  • Process and procedure. The larger the provider, the longer it takes to get anything done. This is not necessarily a slight; if you add the wrong static route, you can down 10 neighborhoods or worse. That procedure is there for a reason, even if it does not always work. Either way, if you hate that sort of thing, working at any large provider will frustrate you.
  • Transit traffic. In a corporate environment the end user is in your network. In a content network, the content is in your network. In a provider network, typically neither is. This has interesting security implications (maybe I’ll dedicate a post to those). This does not apply to full hosting providers (where you have root on the customers’ servers), or in some cases to the business units that provide hosting inside a traditional ISP.
  • Legacy stuff. Providers tend to move slower than…well, anyone outside the DMV, really. You are bound to come across things you read about but did not expect to see in production, like RIP, Frame Relay, or a router the vendor stopped supporting 3 years ago.
  • Silos. Chances are you will not know the people fielding support calls for work you do, or if you field support calls, you will not know the people responsible for the design work. Everyone is abstracted.
  • Lifers. For some reason, mid-to-large providers have a relatively massive number of people who have worked there for 10+ years, something fairly unheard of for us Gen-X geeks. There are political and technical repercussions here, but tact and self-preservation demand I leave them to your imagination.

Career Implications
If you are starting out in the networking field, it helps to know where you want to go. Corporate environments are great for job security. They are everywhere, so it is pretty easy to land a new job fast. If you want to move into management, this is a great place to work because you can move from working on a 500 user network to managing a 100 user network and you will have a “been there, done that” aura. The down side is non-tech companies treat IT as a bill, similar to electricity. You will have a variety of technologies to work with, but the budgets will not have much fun money.

With content and provider networks, you move up the totem pole. In a content network, the network is critical to the business goals; a single minute of downtime is very quantifiable in damages, so you can expect more wiggle room in the budget for security and redundancy. On the other hand, you spend a great deal of time on logistics, like counting free ports and ensuring the next wave of circuit upgrades have optics.

In a provider network, the network *is* the product, so your team is the top of the heap in many ways. Instead of being the enabler for delivery of applications or content, applications exist to enable you. Budgets grow to include things like *GASP!* labs. The tradeoff for this maniacal power is stress. As you get closer to the center of attention, the stomach aches and restless nights climb along with the accolades and budgets.

I highly recommend any network engineer work in all three arenas if at all possible. The technology focus is different in each one (with leakage obviously) – VoIP vs load balancers vs MPLS, for example. But the soft skills are what distinguishes the architect. Working in operations in each environment forces you to learn what providers exist where (and which to avoid…), peering exchanges and their ettiquite, how to work within companies with vastly different models, and just boatloads of other things that make you more knowledgeable and hence valuable. You also start building your professional network, and within a few years you have ex-coworkers strewn about the landscape, awaiting your awesome prowess with the giddyness of a child on Christmas eve.


  1. says

    I’m currently in my first specifically network oriented role (after a 7 year hermit-like existence providing generic IT adminstration and support for an SME), so this was a useful little article, and appropriately thought-provoking. Provider network sounds like the most fun, imo. Many thanks.

  2. dbknill says

    Great article. In terms of career implications, I’d add that in my experience that corporate networks are also the greatest long-term opportunity for consulting (if someone is inclined to do that sort of work), as many enterprises are either under-staffed or do not have the resources to specialize in particular technologies.

    • ktokash says

      Agreed. I’ve hemmed and hawed a bit myself on which path to follow. If you want to get a full-time gig with that architect title you need to work at a company with a large and complicated network that requires an architect, and I think CCIE-wise you’d be best served going R&S and then maybe SP. If you’re more of a scrapper and want to 1099 yourself out at $100-300/hour corporate networks are the way to go, with an R&S and maybe the Security CCIE.

      Right now I’m straddling the fence still and honestly I suspect it’s hurting me in both cases.

  3. Jamie says

    Great article Keith. I tend to find there can be a degree of overlap between the Corporate and Content fields however. I work for a Financial company, we have many large offices which we manage the networking for, but we also have several large DC’s which are serving web content to external customers, which again, we manage the network for. Our scope goes from large scale nexus 7k/5k/2k deployments to aging stacks of 2960’s in the build access layers.

    • ktokash says

      I dealt with some of that overlap at Myspace. We were pushing so much outbound traffic and so little inbound (pretty common for content nets) that we were able to provide ISP services for sister companies and corporate offices, pretty much for the cost of cross connects. The corporate users were inbound heavy, but 500 of them might pull 300Mbps at peak, while we were already paying for 60Gbps of outbound with about 1/5th that level being used on inbound. It was a really good fit. It also made us work with the corporate IT guys from the mother company and share their pain.

      # Edit – none of this is sensitive information. The entire thing came crashing down and these relationships and networks no longer even exist. Haven’t for a few years.

  4. says

    From my experience working in Higher Education networking, I can attest that while they do in fact exist, they’re not much different from the way you described a “Corporate Network”. There’s a lot of user interaction, budgets are tight and IT is treated as an expense. One thing I would add is that in Higher Ed, BYOD more prevalent and network access needs to scale a bit better to handle the constant fluctuations in users.

    Great article, too.

  5. says

    I have to agree the the time commitment for Service Provider and Content Provider networks is the greatest and since by nature they are 24/7 on-call and odd hours are the norm. Also while service provider network have the neat toys, they do tend to nickle and dime vendors, customers, and employees alike. However much is to be said of the job security of working with service provider networks, and knowing that your paychecks will just keep coming as long as you keep working hard.

  6. says

    Great article. I would argue a fourth network type needs to be added. The financial transaction network 😉 Working on one is rather unique, and has some similarities with big data / compute clusters.

    • ktokash says

      I’d like to see what life is like on a financial transaction network. The little I’ve read about stock exchanges and the like definitely paints a stressful picture, with all the “CIA triad” (confidentiality, integrity, availability) fighting for dominance, and the added problem of latency requirements.

  7. says

    I would recommend if you can to try and work for an integrator or outsourcing company at some stage as well. I currently work for one and we are exposed to a variety of environments. While most are corporate these comprise of Resource companies, financial institutions, education, SMB and providers. So the range of technologies, people and process is ever changing.

  8. says


    Great post! I’ll add another factor to the mix for US-based readers: geography. If you are interested in taking the service provider path, living in Northern Virginia has an advantage in that almost every provider has a major presence here. You have options that other regions can’t match. Tired of working at or selling to providers? You can make the leap to the federal space, which will look familiar to those with enterprise experience.

    • ktokash says

      Ashburn is definitely an anomaly in that you get access to every major provider in the world without living in (or near) a city. Personally I love city life, but plenty of people hate it passionately. It’s nice to know you don’t need to ride subways or hear car alarms every night to be in a hub. LA is awful like that – the biggest connectivity hubs are downtown and near LAX, and both those places are clogged with traffic. Rush “hour” is really rush 4 hours in the morning and again in the evening.

  9. says

    “or a router the vendor stopped supporting 3 years ago”

    I had to lol. You know how many Riverstone products I still see in SP networks? They ceased to exist as a company 6 years ago and were bought out by Alcatel-Lucent. They still keep chugging along though. I don’t think I’ve ever seen a Riverstone crash, but they are so out of date.

  10. David Battaglia says

    How does someone get into these positions if they have 5.5 years of experience a bach in computer network systems but no real world application with cisco equipment. It seems its a road block that keeps on getting harder and hard to bypass. I am not trying to give my hopes up but I am considering going the development route. Where I live currently I did a search for CCNA and CCNP in dice and returned only 2 results for the need. I am confused as far as what I want to pursue I do like networking but over the past years the opportunities seem far and wide especially with the emergence of cloud computing…any thoughts would be more than welcomed !!!


    • ktokash says

      Dynamips is your friend. My buddy worked through his entire service provider CCIE on a PC running Dynamips with a bunch of simulated routers. The big hurdles are:
      – Getting it running, which takes about an afternoon, so no big deal
      – Finding a Cisco IOS. Dynamips boots a real IOS, but it’s illegal for me to offer you one so you need to dig one up somehow. It’s a little shady, but far less so than working in finance so have at ye.

      Also, I know it’s a lot harder than it sounds, but sometimes you just have to move where the work is. Probably half of LA would rather live elsewhere, but this is where the jobs are. Work up to a senior role and you can cherry pick jobs where you want to live, or just work remotely. But to start go chase down a gig in a city or tech center like Irvine.

  11. says

    Cool post, wouldn’t the higher education networks also have the students as well as the employees be the IT’s ‘customer’?

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