F5 Friday: App Proxy or ADC?

(Editors note: the LineRate product has been discontinued for several years. 09/2023)

Choosing between BIG-IP and LineRate isn't as difficult as it seems....

Our recent announcement of the availability of LineRate Point raised the same question over and over: isn't this just a software-version of BIG-IP? How do I know when to choose LineRate Point instead of BIG-IP VE (Virtual Edition)? Aren't they the same??

No, no they aren't. LineRate Point (and really Line Rate Precision, too) is more akin to an app proxy while BIG-IP VE remains, of course, an ADC (Application Delivery Controller). That's not even pedantry, it's core to what each of the two solutions supports - both in their capabilities, their extensibility, and the applications they're designed to deliver services for.

Platforms and Proxies

First, let's remember that an ADC is a platform; that is, it's a software system supporting extensibility through modules. That's why we have BIG-IP . Because BIG-IP is really a platform, and its capabilities to deliver software defined application services (SDAS) are enabled through the modules it supports. Whether it's BIG-IP on F5 hardware or BIG-IP VE in the cloud or in virtual machines, it's still an extensible ADC platform.

LineRate Point is a layer 7 load balancer; it's an app proxy. It's primary goal is to serve HTTP/S applications with scalability and security (like SSL and TLS). It's not extensible like BIG-IP VE. There are no "modules" you can deploy to expand its capabilities. It is what it is - a lightweight, load balancing layer 7 app proxy.

Extensibility in the LineRate world is achieved with LineRate Precision, which includes node.js data path programmability (scripting) as a means to create new services, new functionality, and implement a variety of infrastructure patterns like A/B testing, Canary Deployments, Blue/Green deployments, and more. That's where the confusion with BIG-IP VE usually comes in, because in addition to its platform extensibility, BIG-IP VE also enables data path programmability through iRules.

So how do you choose between the options? There's BIG-IP on F5 hardware, BIG-IP VE (virtual) and cloud (AWS, Azure, Rackspace, IBM, etc…), LineRate Point and Precision for cloud (Amazon EC2) and virtual as well as bare-metal.

The best way to choose is to base it on (wait for it, wait for it) the application for which you need services delivered. C'mon, you saw that coming - it's an application world, after all, and F5 is always all about that application.

Applications, Scale and Service Delivery

It really is all about that application. The scale, the nature of the business function the application provides, and the services required to deliver that application are critical components in the choice of what is basically ADC or App Proxy. And you know me, a picture is worth at least 1024 words, so here it is:

The first assumption we're making (and I think it's a good assumption) is that if someone deployed an application and is using it within the context of the business (or line of business or department or, well, you get the picture) then it's important enough to need some service. Maybe that's just scale or availability, maybe it needs security or a performance-boosting push, but it probably needs something. What it needs may be dependent on the number of users, the criticality of the application to productivity and profit, and the sensitivity of the data it interacts with.

Given that set of criteria, you can start to see that business critical and major line of business applications - ERP, Sharepoint, Exchange, etc... - have few instances but thousands of users. These apps require high availability, massive scale, security and often performance boosts. They need multiple application services.

That means BIG-IP*, and probably BIG-IP on F5 hardware or, perhaps, the deployment of a High Performance Services Fabric comprised of many BIG-IP VE using F5 Synthesis. Either way, you're talking high capacity BIG-IP.

As we move down the triangular stack, we start running into line of business apps that number in the hundreds, and may have hundreds of users. These apps are of two ilk:

1. Those that require multiple application services, and

2. Those that require data path programmability

Now, the app may need one or the other or both.

The first question to ask (and this isn't obvious) is what protocols do the applications support?

Yes, that actually is very relevant. Line Rate is basically providing app proxy services; that means app protocols like HTTP and HTTPs. Not UDP, not SIP, not RDP or PCoIP. If you need that kind of protocol support, the answer at this layer is BIG-IP VE.

If the answer was HTTP or HTTPS, now you're faced with a second (easy) question: do you need multiple services? Do you need availability (load balancing and failover) plus performance boosting services like caching and acceleration options? Do you need availability plus identity management (like SSO or SAML)? If you need availability plus then the answer, again, is you should choose BIG-IP VE.

If you just need availability, now you get into a more difficult decision tree. If you want (or need) data path programmability (such as might be used to patch zero-day security vulnerabilities or do some layer 7 app routing) then the question is what language do you want to script in? Do you want node.js? Choose Line Rate Precision. Want iRules? Choose BIG-IP VE. There's really no "right" or "wrong" answer here, it's a matter of preference (and probably skill set availability or standard practices in your organization).

Finally, you reach the broad bottom of the triangle, where the number of apps may be in the thousands but the users per app is minimal. This is where apps need basic availability but little more. This layer is where orchestration support (robust APIs) become as important as the service itself, because continuous delivery (CD) is in play as well as other DevOps-related practices like continuous integration and testing. This environment is often very fluid, highly volatile and always in motion, requiring similar characteristics of any availability services required. In this layer of the enterprise application stack, Line Rate Point is your best choice. Coupled with our newly introduced Volume Licensing Subscription (VLS), LineRate Point here offers both the support for the environment (with its robust, proper REST API) and its software or virtual form-factor along with excellent economy of scale.


Hopefully this handy-dandy guide to F5 and enterprise application segmentation helps to sort out the question whether you should choose BIG-IP, BIG-IP VE or a flavor of LineRate.

Happy Friday!


* Oh, I know, you could provide those services with a conga line of point products but platforms are a significant means of enabling standardization and consolidation, which greatly enhance overall value and lower both operating and capital costs.

Updated Sep 26, 2023
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