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The Hedge 52: Tobi Metz and the Technologist Question
Tobi Metz asked What is a Technologists? in a recent blog post. Tobi joins Tom and Russ on this episode of the Hedge to expand on his answer, and get our thoughts on the question.
History of Networking: Scott Bradner and the Early Internet at Harvard
Scott Bradner was given his first email address in the 1970’s, and his workstation was the gateway for all Internet connectivity at Harvard for some time. Join Donald Sharp and Russ White as Scott recounts the early days of networking at Harvard, including the installation of the first Cisco router, the origins of comparative performance testing and Interop, and the origins of the SHOULD, MUST, and MAY as they are used in IETF standards today.
Weekend Reads 041520
…as always, I’ve saved potentially controversial articles for the end…
Weekend Reads 040320
Weekend Reads 011020
Service Provider Tech Doesn’t Apply?
Service provider problems are not your problems. You should not be trying to solve your problems the same way service providers do.
This seems intuitively true—after all, just about everything about a train or a large over-the-road truck (or lorry) is different from a passenger car. If the train is the service provider network and the car is the “enterprise” network, it seems to be obvious the two have very little in common.
Or is it?
What this gets right is that if an operator sells access to their network, or a single application, their network is likely to be built differently than the more general-purpose designs used in organizations that must support a wide range of applications and purposes. These differences are likely to show up in the choice of hardware, how the network is operated, and the kinds of services offered (or not).
What this gets right is operators who sell access to their networks, or support a single application, always seem to build at a scale far beyond what more general-purpose networks ever reach. Microsoft and Facebook number their servers in the millions, and single purchase orders include thousands of routers. eBay and LinkedIn number their servers in the hundreds of thousands, and their routers and switches in the tens of thousands. How can a small enterprise network of a few hundred servers be anything like these larger networks?
What this gets wrong is assuming none of the technologies, tools, or attitudes from these larger-scale networks is every applicable to the smaller networks many engineers encounter on a day-to-day basis.
All those networks with BGP deployed in their data center fabrics are using technology designed primarily for interconnecting intermediate systems on the default-free zone—in other words, for connecting the networks of transit service providers. All those networks with OSPF deployed are using a link state protocol originally designed to provide edge-to-edge reachability in transit service provider networks. All those networks with IS-IS deployed are using a link state protocol originally designed to provide connectivity to large-scale telephony-style networks.
What about transport technologies? The only transport technologies originally designed specifically for “enterprise use” have long since been replaced by optical technologies designed for large-scale provider or “hyperscale” use. Token Ring and ARCnet are long gone, as is the original shared medium Ethernet, replaced by switched Ethernet largely over optical transport. Even current general WiFi is primarily designed for public operator use cases—look at 5G and WiFi 6 and note how public operator requirements have influenced these technologies.
The truth is there is no “pure” enterprise technology; following the dictum that you should not use “service-provider technologies” in your network would leave you with … no network at all.
There is a second realm where this line of argument falls flat, and its more important than the question of which technologies to use: the techniques and attitudes learned in the operation of truly large-scale networks hold valuable lessons for all network engineers. Should you use a spine and leaf topology in your data center, rather than a more traditional hierarchical design? The answer has nothing to do with scale, and everything to do with flexibility in design and operational agility. Should you automate your network, even if its only ten routers? The answer has nothing to do with what Amazon is doing, and everything to do with how much time you want to spend on configuring and troubleshooting versus responding to real business needs.
Think of it this way: the driver who drives the large over-the-road truck is still going to learn lessons and instincts about driving that will make them a better driver in a minivan.
Come join me at NXTWORK in November to continue the conversation in my master class on building and operating data center fabrics, as I explore how you can apply lessons from the hyperscale world to your network.