Software Networks: a “Blue Ocean” of control loops…
Thursday, October 4th, 2012 by Antonio ManzaliniCurrent “ossification” of IP (over optical transport) networks is creating limitations for Operators in the development and deployment of new network functionality, services, protocols, security designs, management policies and approaches…and other element that are essential to cope with the increasingly complexity of future networks.
Today to launch a new network services is becoming complex and expensive, often inhibiting the rapid roll out of new revenue earning. Looking at the future, this is an important bottleneck to be overcome. A part this, future networks should also be able to reduce operational and capital expenditures (OPEX and CAPEX): OPEX reduction can be achieved by easing human operators (and reducing human mistakes) in managing and configuring automatically equipment and network functionality; CAPEX reduction can be achieved by postponing network resources investments (e.g. optimized use of available resources), for example by exploiting multiple “constrained optimizations“ (i.e. practically this can be achieved by deploying into the network equipment – and/or in the management control systems – several “control loops”) capable of load balancing, traffic engineering, optimized allocations, resources negotiations, etc.)… This means a lot of software, as I’ve pointed out in former post.
Well, in a few words, future networks (which are including Users’ devices and “Things”) will look like ecosystems of pieces of software interacting with each other, and – just like in any ecosystem – self-organization will be the result of sets of “constrained optimizations“ and dynamic games.
One may ask if the emerging Software Defined Network (SDN) paradigm can be seen as a step in this direction. Yes, it is likely to be, even if – in my opinion – the major disruptiveness of SDN will be played at the (and beyond) the edge. This is where autonomics and self-organization have to play a major role: in fact traditional management is failing due to pervasivity and complexity.
Concerning management, have a look at this recent post (from a well-known Expert in network management, who I know personally) addressing how current SDN proposals are not (fully) taking account of the network management functions, specifically the relationships between the logically centralized control plane and the management plane. Interestingly the Author argues that the control plane (even if very advanced) can not replace the management plane. What I like here is the problem formulation: what we’ll have to face in future software network will be the orchestration of multiple controllers! Future networks will have multiple control loops that must be situated in order to accommodate multiple data formats in multiple languages at multiple levels of abstraction.
Imagine the edge: a sheer number of nodes, devices, “things” will interact each other competing, cooperating and negotiating resources.
I believe that, in contrast to today where competition exists only at the application level, future network at the edge will open new business’ dimensions (blue ocean): negotiations, incentives, cooperation and competition will boost the long-term value of the network architectures — like in ecosystems, where evolution select the winning species, winning services will succeed, grow, and promote further investments, while losing ideas will fade away.
On the other hand introducing sets of control loops into (both in fixed and mobile, think about SON) might potentially bring to inconsistencies and non linearities in the network behavior (e.g. due unwanted couplings or interactions, or missing coordination) thus creating instabilities and abrupt phase transitions, which can rapidly propagate.
This is a risk which each ecosystem is running: singles species may have feedback mechanisms that would ensure the population’s stability were them alone, but when together global state transitions to instability regions may occur as the number and strength of interactions among species increase.
The real challenge I see is designing nodes and devices local rules and control/management planes (i.e. creating an ocean of control loops beyond the edge) in a way to enable thriving and stable ecosystems.








