Jamie Anderson interviews Pierre-André Rulmont, the
chief technology officer of Belgacom’s wholesale
division, about a daring transformation to its all-IP network
— in just two days
Pierre-André Rulmont (above) is CTO of BICS, a
member of the Belgacom group that operates in the international
carrier business. He has been within the company for 10 years,
acting in many roles from engineering to IT management, and has
been CTO for the past two years.
Can you talk about the kind of business that BICS is
Pierre-André Rulmont: BICS is in the
business of international carrier services. We deliver global
solutions for voice, messaging, roaming, connectivity and
mobile financial services to hundreds of telecommunication
providers around the world.
This means that our main activity is to interconnect fixed and
mobile operators to provide international services. Typically
our customers are incumbent operators but also any size and
type of mobile operators from anywhere around the globe.
BICS a joint venture of Belgacom, Swisscom and MTN with a
continued focus on value added services for mobile operators
and a strong growth strategy that enabled us to reach a
world-leading position both on the international voice and
mobile data markets.
What is the size of the business?
Rulmont: BICS’s core business is international wholesale telephony
services. In this market we are in the top five. To give
some kind of reference we have about 5% market share as this is
still a very fragmented market. We run more than 25 billion
minutes of international telephony traffic on a yearly basis.
Our network is interconnected to more than 600 operators around
Can you give us the background to your NGN
Rulmont: The company has been growing tremendously
over the last 10 years. When I joined the company BICS was
running a fraction of the current volume of traffic on 20 year
old TDM switching infrastructure.
BICS is operating in a very competitive international market.
The success of the company is based on balancing constantly
decreasing margins with strong traffic growth, not only via
organic growth but also consolidation with the carrier
activities of Swisscom and the MTN group. This was putting a
lot of pressure on the legacy infrastructure inherited from the
The other key aspect in this project is the industry move to
all-IP. The international market is certainly on the leading
edge. Everybody is talking a lot about it and every operator in
the world knows that its network over time will be all IP. The
question is what will be the speed of this transformation of
the legacy network, especially among the incumbent operator
BICS had a lot of legacy infrastructure from the past,
representing our core network and was of course an asset in
terms of connectivity and in terms of connected operators.
Transforming this to all-IP was a real challenge especially for
such a heavily interconnected network. This is a typical
international carrier’s issue as most of domestic
networks only interconnect with a limited set of other
What kind of transformation strategy did you
Rulmont: We decided to go for what we called a "flash
cutover", meaning to change the complete switching
infrastructure in two nights — that is, 50% of the
capacity per night. This was highly ambitious compared to the
traditional way of transforming a network which usually
consists of commissioning a new platform and migrating the
customers one by one over a fairly lengthy period of time.
This decision for a cut-over approach was mainly driven by the
need of limiting the business impact and the difficulty to
build a strong transformation business case. First of all, a
slow transition would have in our case meant an expensive
transformation in terms of time to deliver and manpower to be
allocated to the migration of hundreds of interconnection
around the world.
Secondly, a slow transition is straightforward in a fairly
static network but in our business we need to realise hundreds
of routing updates on a daily basis.
This means that during a traditional transformation process,
our network operations teams would have had to operate the
legacy and new infrastructures, manage two routing
environments, and on top of this the interaction between these
while moving customer from one platform to the other. This
would have been a very tricky juggling process that could have
negatively impacted our business agility.
That being said, most of the carriers around the world still
choose incremental transformation of their network
infrastructure, as the flash cut-over approach seems too high
Can you talk about the implementation part?
Rulmont: The flash cut-over approach required us to
build beside the existing platform a completed mirrored
infrastructure which had exactly the same size, same
configuration, and same features, while at the same time being
completely integrated in the OSS and BSS environment while
The flash cut over could then take place, and during one night
we switched over 50% of the old infrastructure to the new one
and the remaining 50% a second night six weeks after the first
Two nights were required to mitigate the risk but also to
ensure service continuity to our customer as the transition
process took around 10 hours. During the transition, all of our
customers had dual connections and we performed the transition
during offpeak periods to ensure that no customer traffic would
be negatively affected.
From a timing standpoint, the construction of the new
infrastructure, the commissioning and configuration took nine
months, followed by another three months of preparation for the
What were the biggest challenges?
Rulmont: The technology learning curve is a big
challenge. In a more incremental approach, network operations
teams are used to master new technologies with a slow
introduction process, starting with a small configuration,
adding a few beta customers and growing progressively while
solving scalability and integration issues. In a flash cutover
everything has to be anticipated and it all happens in one
The other big challenge was managing the reference data.
Mirroring infrastructure is not just copying the configuration
from one switch and putting it on to another. You need to be
able to link it to your customer database.
We managed to mitigate the risks of errors in this space using
transmission equipment to copy the signalling of the production
environment to the offline new infrastructure, while observing
the behaviour via our monitoring systems.
The last big challenge was what we refer to as the residual
traffic issue. When you are the single gateway of all the
telephony of a particular country you need to support all the
traffic that gets in and out of that particular country.
And there are plenty of applications that actually you as an
operator don’t know about. Customised alarm modems
and proprietary or encrypted faxes are typical traffic that
runs very well on traditional infrastructure, and are very
challenging to NGN infrastructure.
On top of this, you cannot detect these issues during the six
weeks’ observation period because those fax-like
devices have retry features that will, in combination with the
network internal traffic distribution mechanism, ensure that
the call will reach sooner or later the old switch. As a
consequence, you can only detect them when 100% of your
migration is done and no way back possible.
What were the main people and change management issues
that you encountered?
Rulmont: Inside our technical community when we came
with this idea of doing a flash cutover everyone was saying
"this is crazy". This is not really the typical way of bringing
an infrastructure of such a size into service.
Even though we had a strong business drive, it was very
important to get the technical community onboard and to
convince them that it was worth taking the risk. The internal
acceptance process of such a decision is, after vendor
selection, the second most critical success factor.
Network operations, engineering and IT people are very
different communities. They don’t mix and match
spontaneously that well, and sometimes don’t even
speak the same language. It is therefore very important to
identify and empower the resources that show interest in both
fields and provide them end to end responsibilities.
With regard to the transition process itself, having a strong
and stable monitoring environment is also key. Disconnecting
50% of the network capacity in such a short time generates a
massive amount of events in all network monitoring systems,
meaning that you could lose control of the network itself.
And finally, this is what allows declaring the success of the
transition. The cutover is a 10 hour process with 200 steps.
After that, you have a window of one hour to evaluate the
situation and from that point, if it doesn’t work
perfectly, you need to roll back and bring the old switch into
Your network monitoring environment needs to be able to recover
very quickly, and you need to have all the tools that give you
the visibility on the quality of service being provided. This
is the project success indicator.
What would be the main piece of advice you would give
to another CTO who would be considering a similar
Rulmont: We have all experienced, in any type of
organisation or technology transformation, that there is always
a good reason to postpone things. My main piece of advice is to
go for an ambitious way forward, and pursue a vision that the
organisation and its people will have pride in delivering. That
certainly helps to overcome the levers of resistance that
elements of the organisations tend to fall back on.
This also certainly helps to build a business case. Many
business cases fail due to lack of ambition and therefore lack
of means to realise the transformation. With an ambitious plan,
you have the resources and can therefore limit the potentially
risky impacts on the business.
The second aspect is to understand that any transformation is
about people and their emotions. If you want to have an
ambitious project, you certainly should not push down with your
view and try to impose your way of moving forward. Show your
team that you have an ambition for them to realise a very
visionary project, but let them come up with the best way to
serve the business and really give their best in order to
support the challenge of the company.
If you have an ambitious project but your people
don’t find the vision and the approach legitimate,
then they will not support you.
The last point relates to the way this project was managed from
the perspective of change. To ensure the huge shift, it is
obvious change management methodologies should be applied.
In this particular project one very interesting exercise was to
put people around the table and ask them to focus on one
subject: "What if things go very bad?"
We also spent a lot of time doing simulations because this
remained a complex process, and simulations made people more
comfortable. Having a strong fallback scenario also allowed us
to take more risks, and increases the commitment of the project
How has the success of the transformation been
Rulmont: The success of any such transformation
project is ultimately measured by the network KPIs, but also by
the lack of "noise" or disruption to clients the day after the
completion of the work.
Perhaps the most significant sign of the success of our project
was the fact that we did not have to set up even a single
emergency client meeting due to unexpected behaviour or
outages. So from this perspective, we can say that the
changeover was an unmitigated success.
We had no network crash and our customers appreciated not being
affected. But at the same time we were very transparent with
them, explaining the process, how ambitious it was, and all
customers have appreciated it.
Some of them have even said they would love to be able to do
the same. GTB
Belgacom upgrades wholesale network to 40
gigabits (GTB report)
Belgacom and MTS wholesale merger (GTB
Industry prepares for IP and carrier ethernet
services (GTB report)
Professor Jamie Anderson is adjunct professor of strategic
management at TiasNimbas, the business school of Tilburg
University and Eindhoven University of Technology