When I started my research on vCPEs, I came across several blogs from 2013-14 where Physical CPE vs vCPE was as hot a topic as NFV and SD-WAN are today. Although, I have planned to primarily discuss Virtual CPE (vCPE) & Cloud CPE in this blog, I do feel that it is worth evaluating Physical CPE at the same time. Since, vCPE in itself is pretty vast as you will see later, I am going to discuss Cloud CPE in my next blog.

So, let’s get started and figure out if physical CPE is in the process of dying?and if that is how it is then if Virtualization alone is the next possible future? But before we do that, let’s consider why virtualization of CPE device was promoted in the first place? The answer is actually very short and simple- Cost Savings! Don’t get me wrong, I am fully aware that money is not always the driving factor behind innovation however we cannot not ignore it. Below are a few other important reasons for considering vCPEs in my opinion:

• Reduction of CAPEX and OPEX.

• Avoidance of Vendor Lock In.

• Pay as you Grow model.

• Upscaling/Downscaling of network resources.

• Deliverance of new services without truck roll.

• Flexible insertion in the network.

• Saves that precious Rack Space. 

At the most basic level, I do agree that vCPE and Cloud CPE are going to be big in the near future. So, if you aren’t already sold on considering Virtual routers yet (CPEs only, not even considering virtual routers at the Core), you should see one of the demos from these software/virtual router vendors showing impressive performance numbers. While you are being charmed in these demos, here a few important questions that you must consider:

• Whether these performance numbers are for a mix of traffic?

• How much performance/throughput is hit when the packet size is reduced?

• What is the cost per port? You must calculate the cost applicable to your network needs and not get carried away with the innovation only!

• How does adding more features like QOS, ACL, firewall, netflow etc. (which are standard on most of the physical CPEs) impact the performance of these software routers?

• How easy is it to deploy and troubleshoot and if there are any additional complexities (there are multiple flavors that exist today)? 

IMHO, I still don’t think that as of today vCPE or Cloud CPE can replace the physical CPE completely. However, there are a few used cases where it makes complete sense to replace the physical CPE with vCPE. For instance, it’s a no brainer to replace the low performance physical routers that still processes packets in software with a virtual router. Having said that, with all the innovation happening with DPDK, SR-IOV etc and constant improvement in performance on the chip, I don’t think that we are too far away from the vCPE or a Cloud CPE world. As of today, careful consideration is required to take advantages of both physical and virtual world. After all, they can simply coexist.