This is my prediction. You can quote me if you like.
One day all routers will be virtual.
The ASR has been virtualised for some time as a Cisco CSR 1000v, so I expect that early editions of VIRL’s XRVR will be IOS-XE like – perhaps with some Titanium (NXOS) support. I haven’t heard anything good about previous versions of Titanium, so hopefully that will improve.
Networking is slowly undergoing an evolution (revolution even maybe). Just as computers used to be something that people had on their desks and mounted in racks in data centres, routers and switches used to be bits of hardware that we programmed via a CLI accessed by a console cable.
This is no longer the case. Computers are virtual and exist as virtual machines running on some hardware somewhere and accessed by some “Human Interface Device“. And because the computer paradigm is so fluid, the demands on the underlying network are forcing the network to become fluid as well, to make it possible to track and control the data flows to virtual machines that can move physical location in an instant. And to achieve this kind of fluidity, routers must become independent of the current hardware and turn into software-based “flow facilitators” that recognise that a particular type of traffic travelling from this particular host to this particular service requires these particular attributes through all the bits of hardware that the traffic needs to flow.
Cisco and others are working to provide these kinds of routing paradigms and in the future you will hear a lot about SDN (Software Defined Networking) and terms like Openstack (Network connectivity as a service) and Openflow (the control protocol) which will provide the APIs needed to provide “Infrastructure as a Service“. The role of the networking engineer is going to become less dependant on understanding how IP works and more dependant on understanding how services interact with each other.
What you see today (or Jan 2014 or whenever VIRL is released) is a glimpse of how future networks will be configured – in software. The problem for VIRL is going to be licensing – how to give VIRL away without giving the product away for free or cheaply.
So I suspect VIRL will be released with certain restrictions on the amount of traffic it can pass etc. (Just like the CSR 1000V has throughput options based on licence). But VIRL is not just a new simulation environment. It IS the new environment.
VIRL provides a GUI front end based on the VMMaestro GUI. Which is based on Java I understand. And then controlled by OpenStack – which is Open Source. So who knows, there could well be an opportunity for GNS3 to add VIRL routers to GNS3 topologies via OpenStack. But that will require lots of investigation!