A Network Artist : Marrying SASE (SDWAN) with 5G - The Marketing, The Myths & The Fallacies & How to Get it Right (An Architectural Perspective)

Monday, October 31, 2022

Marrying SASE (SDWAN) with 5G - The Marketing, The Myths & The Fallacies & How to Get it Right (An Architectural Perspective)

When almost 3 years ago I wrote about why having an inbuilt LTE interface inside a SD-WAN device doesn't really matter, the 5G thingy was still relatively new.

During a recent Enterprise Architecture Consulting engagement, I was asked by one of my client if they should really care about 5G and 5G interfaces on the variety of SD-WAN platforms that were pitched to them by different Systems Integrators (SIs) & MSP (Managed Service Providers)/Telcos.

So let's start with a simple question - "What problem we are trying to solve?"

In general you will see a few types of customers in SASE/SD-WAN market :

1. Which have Technical/Solutions architects those are completely sold on vendors marketing (50% of the crowd)

2. Those who wants to jump on the bandwagon due to fear of being left behind in the similar industry or by the competition (25% of the crowd)

3. Those who always are either too excited by technology or have a lot of money to throw onto the problem (the next 20%)

4. Those who can really map business capabilities to technology capabilities (the rare and the last 5%)

In general, you would often find a few ways the 5G gets included into the solution by solution providers such as :

Design 1 - You have a site (mid/large size) which either has got hybrid connectivity (MPLS + Internet) or 2 x Internet connects, while keeping 5G cellular as a last resort backup link in an event of a total failure.

Design 2 - A small site that usually runs on a single internet link and keeping 5G as back for last resort.

Design 3 - 5G as backup of last resort onto your DC WAN edge

Now in general it doesn't look like a bad idea to have a 5G interface but here are few of the important considerations:

- In general your DCs/COLOs and Campus networks would be setting on racks behind thick physical building structures (remember your Wi-Fi coverage problems even while your APs are sitting inside), so very often you would expect coverage issues. Now one of the argument here might be that I can install an external antenna of some sort on top of building or floor and run a fiber cable connection from there. Fair...but:

> Now you got to get approval for installations, cable runs, have administrative processes and safety processes in place and what not (What if the lightening hit the antenna?).

- To my understanding, most SASE/SD-WAN solutions don't offer any visual monitoring, reporting & troubleshooting tools for - Checking 5G signal strength, 5G interface troubleshooting, Dummy traffic probes etc.

- Interestingly enough now you need even a more complex traffic distribution, traffic prioritization, traffic failover, traffic desired SLA/performance metrics and other set of policies into the mix. And even if you end up doing that successfully, how you are going to document it for the operations ?, Is your EMS/NMS equipped with such capabilities ?

- From the network architecture perspective, you just added an another layer of complexity. Assuming this 5G interface is an HW module, you got to now deal with: New stack of software and protocols within your fancy WAN edge device (3GPP standards), New interaction surfaces, New potential grey failures.

- You just end up adding the more state into the network (State, Surface & Optimization tradeoffs)

- You need to now have life cycle mgmt. in place for your 5G interface (HW/SW Upgrades, Monitoring, Management, Refresh etc.) beside that fact that the 5G specifications often vary country to country (even from Telco to Telco) and now you need to keep track of Data Plans, Data Usage, Availability & Performance Mgmt., Cost Mgmt. and what not. (Remember your data plans are pretty limited in general?)...imagine to solve these problems at a global scale deployment dealing with different MSP.

> How to you move to 6G if it comes out in the next few years ?

Now after all these interesting questions, we may still ask:

1. What are the better alternatives today ?

2. Where 5G might still make sense ?

Answering the first question, IMHO I would still recommend you to opt for a broadband connection and avoid 5G unless you have a very particular problem or scenario because:

- With broadband you are still dealing with Ethernet connection between your CPE and broadband router/device which is a pretty familiar connectivity model and protocol stack to deal with.

- In general your broadband data plans are much bigger

- You don't need to deal with another MSP for service management perspective as in general your ISP would have a common portal to give you a view of all MPLS, Enterprise Class Internet and Broadband based Internet connections. (Also mind that historically your SPs were building two parallel networks for ISP (Internet Service Provider) and MSP (Mobile Service Provider) business units, though those are converging now more and more)

- With everyone hit by pandemic that accelerated WFH culture, in both developing and developed countries you would expect to have broadband being available very easily and at the affordable prices. The only places you might still face availability issues are Tier-3 cities and so forth. But for most part that is not a technology problem but your SPs wanting you to stick with cellular connectivity to drive more profits (So its an intent problem rather)

- My own research suggests that in many developed countries getting a broadband will cost you far less compare to the enterprise class 4G/LTE/5G/Private 5G connection

Answering the second question, here are few use cases for your consideration:

- 5G as part of your SD-WAN transition plan (Legacy to SD-WAN)

- Your last mile hybrid or other wired connectivity model still runs on same fiber or shared media (true path diversity problem)

- One or both of you last miles are on Microwave (Should be pretty rare now)

- 5G as a OOB (Out of Band) management option

- Movable workplace and offices (Eg. Marketing/Sales & Promotion offices or moving semi-trailer trucks often used in variety of businesses)

- Specific operating conditions such as in Oil/Gas & Mining industries

- Edge compute/Cloud

- IoT Platforms

HTH...

A Network Artist 🎨

Further Readings: