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NewsGlobe: Interviews
Southern Light supercharges Ethernet
Leverages PBT to ensure network service resiliency
by Sean Buckley
Eric Daniels, COO of Southern Light, a Mobile, Ala.-based optical services
provider, is not your typical telecom executive.
In fact, neither Daniels—a former military man—nor either of his founding
partners has a telecom background at all.
Similar to many emerging service providers that wanted to cash in on the
rising Internet superhighway, Southern Light was founded
initially to provide dark fiber services in 1998 for other carriers in the Gulf
Coast region. (see Figure 1.)
There was one problem, however. By the time the Southern Light
became operational in 2001, many of the carriers it had hoped to sign up
as customers had already built their own fiber backbones.
This meant that Southern Light needed to find a new model.
“Instead of building a long-haul dark fiber network, we started building
out small metro rings in Mobile, Al. and Pensacola, Fl.,” said Daniels. “We
just took the approach that everyone built the interstates, but no one
has built any off ramps.”
Beginning with video transport service for television broadcasters,
Southern Light’s business has quickly expanded into providing services to
service providers and enterprises, including dark fiber, collocation,
Ethernet transport (transparent LAN and Dedicated Internet Access),
and traditional TDM-based SONET.
Enhancing Ethernet’s reliability
While Ethernet is a core part of Southern Light’s metro services offering,
Daniels holds no punches in saying Ethernet has been nothing but easy
to deploy in a carrier network.
“You know, Ethernet is the ugly sister that shouldn’t have made it to the
prom, but she did,” he said. “Ethernet was not designed for metro
transport [but with] creativity and lack of available resources, we, as
an industry, have made it work.”
At issue were a series of technical gremlins, particularly Spanning Tree Protocol (STP), which, while not necessarily an issue in the Ethernet-based LAN, were quite
problematic in a Layer-2 carrier metro network. In fact, spanning tree issues were a major contributor to outages on its VoIP LEC (Local Exchange Carrier) customer’s networks.
With a customer base that includes government, large enterprises
, wholesale services, not to mention broadcasters, Southern
Light could not afford to have these issues mounting as it tried to ramp
up its Ethernet service capabilities.
Traditionally, Southern Light used to run a Layer-2 network off two
core switches to provide Ethernet services, but when that began to
have issues, it switched to using Layer-2 switching off a single core
switch.
The operator has now found its savior in Provider Backbone Transport
(PBT), a technology that enhances Ethernet transport with SONET-like
deterministic qualities.
Joining other early adopters, including notably BT, Frontier
Communications and Dakota Carrier Networks, Southern Light is the
latest service provider to tune into the PBT channel. (See Nortel stirs
up the PBT pot)
Southern Light has deployed Nortel’s Metro Ethernet Routing Switch
(MERS) 8600 in its core backbone. It has installed the 8600s in each of
its metro rings initially. In addition, it is deploying Nortel’s 1800 Ethernet
Service Units (ESUs) on the edge network. (See Figure 2.)
Daniels explained that by using PBT, they can now deploy Ethernet
services without worry.
“The MERS platforms could prevent a spanning tree incident from
affecting our entire Layer-2 backbone going over to another city, which
literally could have happened before even with MPLS,” he said. “It definitely
improves your network resiliency.”
Eliminating complexity
When it comes to any new technology, Daniels and his technical team
have a "show me" attitude. Colorful Powerpoint presentations and fancy
press kits are not wanted.
Daniels advises all vendors that want to show their technology wares to
basically bring in what they are proposing and they’ll put it in the lab to
see how it works.
This attitude is led by Southern Light’s CTO, a company leader who is
not necessarily keen on deploying every new technology that comes
down the pipe.
“My CTO does not like new equipment; he’s the most anti-new
technology CTO you’ve ever met,” said Daniels. “When he got his hands
on the PBT systems and started beating them up, it became a new
challenge for him to see how he could break it, but he could not break
these systems.”
Along with providing network resiliency, what also sold Southern Light
and its engineering staff on PBT was it looked and smelled like SONET.
“We had implemented MPLS in our core, but it’s pretty complex to
provision circuits across an MPLS core,” explained Daniels about the
rationale to use PBT. “Seventy-five percent of our operations staff has a SONET
background, while only 25 percent have a heavy IP background, and we
needed something to make it easier for our SONET guys to manage an
Ethernet network. PBT is substantially easier to learn and operate than
MPLS.”
Southern Light's only regrest is that PBT wasn't
available earlier when it was doing a previous upgrade of its video network from
SONET to a Resilient Packet Ring (RPR)-based backbone.
“I went back and did the math on a relatively expensive upgrade in 2006
of our broadcast video network and realized I could have done the same
thing if the MERS system had been out there for a quarter of that cost,”
said Daniels.
Wireless kicks the Ethernet tires
While Southern Light’s enterprise and broadcast customer base are the
main users of its Ethernet service, wireless operators’ cell towers, which
make up 25 percent of its lit fiber customers, are also starting to look at
Ethernet as a new medium for wireless backhaul.
Although TDM-based circuits continue to rule the game, the interest in
IP/Ethernet continues to mount.
“Everything we do with [the wireless operators] is still TDM-based, but
there’s a lot of movement on their side to progressively move this to an
all Ethernet backhaul solution,” said Daniels. “They’re dipping their toes
in the water, but they don’t want to jump in yet. It’s plain that it’s
something we need to get ahead of.”
Such a scenario should not be all that surprising as wireless operators
overall continue to ramp up their subscriber bases, a prospect that will
require more backhaul bandwidth.
Recent research from both ABI Research Infonetics confirms that
wireless operators are in the process of migrating towards IP/Ethernet
for wireless backhaul.
ABI Research, while pointing out that the majority of today’s
backhaul circuits are still predominantly T1, says wireless backhaul by 2012 will make
up US$23 billion of a wireless operator’s total capex budget (see Wireless backhaul rises to the top).
Meanwhile, Infonetics Research predicts that IP/Ethernet mobile backhaul
equipment, while still making up a very small portion of the sales of
wireless backhaul equipment as of 2005, will be a $1.8 billion market
by 2009 (see Alleviating Backhaul Pain).
Despite the promise of IP/Ethernet, Daniels cautions that the transition
to IP/Ethernet backhaul will be gradual. A likely scenario is that many
wireless operators will initially use Ethernet to transport data services
and migrate the rest of the services to IP/Ethernet over time.
Whatever way they do it, the migration requires a paradigm shift for the
wireless operator.
“It’s going to be a pretty long time once they are comfortable with the
technology because they have to get their provisioning groups educated
on how you order Ethernet,” he said. “They’re going to have to change
the guys operating their switches from circuit-switched smart to IP
smart.”
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