Hi there! We've updated this blog post with a new post that defines bandwidth on-demand in today's world of cloud, SDN and NFV.  You can read that post here: What is Bandwdith on Demand?

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Unlimited bandwidth.  Everybody would love to have it, but nobody really wants to pay for it.  Even with the constantly declining cost of bandwidth that I’ve talked about previously, the surging amounts of bandwidth required by today’s enterprises can still be cost prohibitive.  

So what’s an Enterprise to do?  One possible solution is to dynamically increase (or decrease) the amount of bandwidth you pay for as demand changes.  In other words, bandwidth on-demand.  But can today’s carrier provide a true bandwidth on-demand service?

To answer that question, I’d like to introduce a new guest blogger.  Jim Morin is Ciena’s Product Line Director in the Managed Services & Enterprise Group and has been blogging on Ciena’s Partner Community for several years now.  Below is Jim’s guest post:



Jim MorinHow will bandwidth on-demand work? This is the 64 million dollar question – how to make bandwidth dynamic?  (Kudos to anyone who remembers where the phrase “$64M question” originated.   Hint, it started out as the $64 question then.)

This is a complex endeavor for a carrier on many different levels and has been sort of a “holy grail” in the industry for a long time.  We know that change will come incrementally and it will take a while for a truly end-to-end fully dynamic bandwidth environment.  But it is possible to do some of this today, and progress is being made for greater flexibility in the future.

Today’s bandwidth on demand


With intelligent platforms like Ciena’s portfolio of packet optical products and Agility software, users have the ability to dynamically increase/decrease a client port’s percentage use of a pre-provisioned network connection.  For example, you may want a storage array on port 1 to change from 10% allocation of the bandwidth, to 90% of the bandwidth, so the array’s replication job gets done faster during a peak load period like end-of-month processing. This is a simple dynamic change to achieve an on-demand increase of allocated bandwidth, and works for any WAN – SONET, IP, Carrier Ethernet.

The above example did not add any net new capacity, so what we also need is the ability to turn on additional capacity too.  Certainly this is easy to do by adding more wavelengths to a DWDM to increase the virtual throughput over the fiber.  If the equipment is pre-provisioned, this is a simple software change, either in a private optical network or a carrier delivered wavelength service.  Carrier Ethernet delivered services work in the same manner – where network capacity could start at 100 Mbps and be somewhat dynamically increased up to 1 Gbps or beyond.  But generally neither of these would be on-demand or easily scale bandwidth both ways – up or down.

A lot of the “thin provisioning” models in storage and elsewhere work on this same concept to dynamically expand capacity on pre-provisioned equipment.

Future bandwidth on demand

True on-demand is bandwidth where you need it, when you need it.  It assumes the physical infrastructure is already installed to support this, through the edge, metro and core to the same on the other side.  It might also assume the ability to transverse more than one carrier, and sort out all the provisioning and billing.  This is a very tall order!

So the first steps will be to break down this problem by offering on-demand services between two known locations where pre-provisioning equipment will make sense because of the expected business volumes.  One example might be between mega data centers, where it is a good guess that high bandwidth workload balancing will occur, even though you don’t know exactly when.

[Learn more about building bandwidth on-demand networks]

Ciena is working on ideas for the software glue to enable the ability to dynamically add, remove or resize bandwidth under software control.  The idea here is that applications like VMware’s vCenter may receive a request for a virtual machine (VM) and storage migration, and Ciena software we’re calling Translation, Arbitration & Control (TAC), can take that request and interface with the Ciena equipment from the edge through the carrier’s infrastructure to make it happen.  Automation and policy enforcement will be important, as well as managing Layer 2 domain extension.

The software interfaces between the virtual environment and the bandwidth infrastructure will define this capability more than the bandwidth type, e.g. wavelength, SONET, IP, Carrier Ethernet.

Benefits from bandwidth on demand

One area where bandwidth on-demand can have a large impact is the leasing of bandwidth between data centers.  Today, service providers and enterprises likely lease required bandwidth from wholesale carriers on a fixed price, 3 or 5-year contract, for a fixed capacity, typically sized around 1.5 times peak load.  This results in paying for bandwidth you're not using a lot of the time.  Virtualizing bandwidth and enabling capacity to be on-demand offers the potential to increase efficiency.

For example, a similar problem occurs with storage and servers which typically operate from 15-40% efficiency.  Virtualization enables companies to drive that efficiency into the 90% range. 

We think virtualized bandwidth could offer the same efficiency benefits if the peak or cyclical loads could be handled with an on-demand service.  We think cloud services and virtualization helps transform the whole computing and networking model into much more of a fluid workload mobility model, with on-demand, pay as you need it type of service environment, at least for the non-mission critical applications.

The efficiency benefits of network virtualization could accrue to both end users and carriers.  For end users, the carrier’s pricing model for on-demand services will hopefully be lower than the fixed rate contract.  For carriers, virtualization should enable them to drive infrastructure efficiencies much higher, lowering their capex and opex costs. 

So bandwidth on-demand for pre-provisioned equipment is really here today, but true dynamic capacity is still a future delivery that is now getting closer to reality.