Connection Oriented Ethernet - InfoVista

FierceTelecom.com
continued from page 14
uptake for the following reason:
A lot of carriers are finally capping
their SONET (synchronous
optical networking) infrastructure
and want to move to a full packetbased
technology. A lot of those
organizations had big SONET
networks and these are the ones
that are driving the COE market.
They are delivering lots of Ethernet
over SONET (EoSONET) with guaranteed
bandwidth delivery. They
realized they needed something
that has to be that good to replace
SONET because the customers
won’t accept anything less than
that, but they are being forced to
move over because they need a
much more scalable, packet-centric
type of service. That’s what is
making COE take off. A number
of service providers I met with
recently said they are still going
through that exact same transition
where they are saying ‘we’re still
going to offer SONET services to
those customers that want it, but
the reality is we want to do Ethernet
over fiber service and COE is
the way to go.’ COE allows them
to have a more cost-efficient, scalable
infrastructure versus SONET.
With SONET, service providers
have to sell bandwidth in 50 Mbps
increments in order to recoup their
investment because every SONET
channel is 50 Mbps. Customers
don’t necessarily want to buy
bandwidth that way, but that’s the
way service providers had to offer
it because that was their transport
infrastructure.
FT: How is the service provider
community responding to COE?
Is it mainly being deployed
by domestic or international
carriers or both?
rS: I am seeing a lot of interest in
both the U.S. and Canada. I know
a large carrier that does broadband
backhaul for their infrastructure
and COE made a lot of sense for
them. Even though their last mile
is copper, their infrastructure is
completely COE-based because
it allows them to offer high performance
Ethernet over Copper
service. Normally, you had buy
fiber to get a high performance
Ethernet service, but with COE
they can offer the same type of
performance over copper.
FT: Earlier, you mentioned
wireless backhaul. How are
wholesale operators that
provide services to wireless
operators using COE?
rS: It is probably one of the biggest
areas of growth. The reason
for that is the wireless operations
had been very stringent on backhaul
even though the data traffic
from the cell phones is best-effort.
Normally, if the wireless operator
has some T1s to a 3G base
station they will backhaul those
over SONET. Even if they have
a SONET infrastructure they can
run COE over SONET to get better
efficiency on their backhaul
network. Today, the vast majority
of backhaul is EoSONET, and
the reason why is the wireless
operators don’t trust the wireline
providers doing the backhaul. They
said, ‘Look, I want you to give
me EoSONET because I know it
works.’ Some service providers
will run COE over SONET and that
allows them to get better bandwidth
utilization over their SONET
backhaul network. These carriers
will do it this way because they
had some T1s from the 3G base
stations. Rather than using SONET
in 50 Mbps chunks, they can
now take multiple Ethernet ports
coming from different base stations,
including 3G and some 4G
LTE, and run it over that SONET
infrastructure and get much better
bandwidth efficiency.
When it comes to COE for LTE
data backhaul, the carriers want
to have a backhaul infrastructure
that prepares them for the future.
Today, LTE is all about best effort
data and their voice is still 3G
voice. They don’t provide voice in
LTE. You can envision in a couple
of years they will move over to
VoIP and will not be doing circuit
switched voice anymore like they
do today for the voice part of LTE.
When they get to that, the VoIP
service will require some stringent
backhaul. By putting in COE today
for their best effort data backhaul,
they’re preparing for the future
when they introduce VoIP. It’s like
planning for the future, but not
really paying any additional amount
because COE is just as cost competitive
with other Ethernet-based
backhaul technologies.
FT: In the COE domain, there
are a number of approaches,
including the Ethernet-centric
and the MPLS-centric views.
What benefits or advantages
does the Ethernet approach
have over MPLS, or does it
depend on the service provider?
rS: You can implement COE
with either Ethernet or MPLS. I
think there are reasons for both.
If you’re an equipment manufacturer
that builds routers, then
more likely than not you would
chose an MPLS-centric approach
because that’s what your product
development organization is used
to. If you’re coming from a pure
Ethernet side as a developer of
Ethernet switches or Packet Opti-
cal Network Platforms (PONP) like
Ciena, Fujitsu or Cyan, you would
probably do an Ethernet-centric
approach. It makes more sense
there, not only from how they sell
products, but also because the
customers they sell products to
are the transport organizations
that know SONET. MPLS is like a
foreign language to them.
COE was actually designed with
SONET in mind. A lot of the standards,
like 50 millisecond protection
switching and fault management,
came from the SONET world and
even uses a lot of SONET terminology.
It would be very familiar
for someone who knows SONET.
There’s an ITU-T standard called
G.8031 that defines linear path
protection, which is called the
same thing in SONET with a working
path and a protection path. If
the working path fails you switch
over to the protect path within 50
milliseconds. It’s very friendly for
SONET/SDH transport people who
are used to those terms. Most
SONET people are familiar with
Ethernet because they’re using
Ethernet to connect their SONET
devices. That’s why the Ethernetcentric
approach is good for that
type of organization because they
are switching their SONET/SDH
networks over to a packet network.
They are asking, ‘Should I
make the leap to MPLS or should
I make a leap to Ethernet? Well,
all of my operational staff knows,
and OSS systems know Ethernet,
so let me go with Ethernet. Why
add an extra layer?’ That’s been
the big driver because MPLS adds
another layer of technology that
they are not familiar with using. l
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