Networking Heresy?
Software Defined Networking, and it’s latest incarnation SD-WAN seem to be all the rage at the moment. Having seen presentations from vendors large and small on the subject recently at Networking Field Day 10 I am still given to thinking there are a few things that get glossed-over by the vendors quite often. Foremost in my mind, is this (potentially heretical thought):
It is all very well creating virtual or ‘overlay’ networks which run over other networks to suit your purposes, but as someone famous once said, you can’t change the laws of physics. Packets must ultimately flow across a medium – wires, fibres or waves. The media doesn’t give a flying fart whether the packet is naked, or clothed in layers of MPLS or GRE headers – if that medium is congested and doesn’t support any form of packet prioritisation, your data is down the dunny.
There’s a trade-off here that perhaps not many people understand when they are shown smooth presentations by manufacturers. It seems to me that:
- Efficient use of network connectivity requires deep understanding from end to end. That’s why you employ network engineers.
- Efficient deployment of network connectivity requires abstraction and overlays to increase ease of deployment (which equals loss of understanding of lower layer protocols).
- Continue reading