Tài liệu The optical last mile doc

Advancing the optical last mile is a proactive, pragmatic approach to the imminent growth of bandwidth demand.. Optical last mile enables a high-bandwidth access to enterprise networks,

Where will it lead us? l ast m ile

To assess the issues and opportunities optical technologies and networks bring

to end-users, we invited six leading experts to our semiannual roundtable

dis-cussion, scheduled for Sept 11, during the Networld+Interop show in Atlanta Unfortunately, that give-and-take session had to be cancelled In its place, we created a virtual roundtable on “The Optical Last Mile,” with our original panel

of experts participating via e-mail, resulting in this interesting and informative dialogue on the optical revolution.

Is the optical last mile really necessary?

Why or why not?

Sandra McWilliams: Fiber is the only available

me-dium that achieves the optimal bandwidth, reliability,

flexibil-ity and securflexibil-ity required by today’s enterprises As the way

we conduct business

contin-ues to evolve, new video and

data applications will tax the

limits of existing

infrastruc-ture Advancing the optical last

mile is a proactive, pragmatic

approach to the imminent

growth of bandwidth demand

Mark Fishburn:

Sep-tember 11th obviously

mag-nified many market trends

already in place, but may

accelerate business benefits

for the high-speed access market Many pieces to the

puzzle—increased demand for home entertainment to

upcoming technology and metro-focused service

provid-ers—make delivery of that fiber economical Layoffs

will presumably lead to an increase in SOHOs looking

for low-cost, high-speed connectivity

Cüneyt Özveren: Given a cyclical economy like this

one, it becomes very difficult to scale IT departments up

and down as market conditions change A solution for this

problem is outsourcing IT requirements Optical last mile enables a high-bandwidth access to enterprise networks, which, coupled with quality of service, enables application service providers to offer outsourced IT services

David Montanaro: Long term, there is little doubt

that the bandwidth requirements of business and residential users will surpass the ability of any other media to handle

it If fiber is the end game, why waste time and money

on interim solutions now?

Brendan Mullooly:

The optical last mile is

nec-e s s a r y i n t h nec-e o v nec-e r a l l scheme; however, we see

it as an ethernet-based, end-to-end solution Only fiber provides virtually limitless bandwidth, as opposed to fixed-wireless or copper-based solutions Where en-terprise users are within easy reach of the fiber-optic infra-structure, they can benefit from virtually unlimited band-width of optical ethernet Offerings from traditional telcos and ATM-based networks are unable to match the robust capabilities of optical ethernet in terms of flexibility, scalability, cost, bandwidth and speed of deployment

Lawrence Prior III: Customers are demanding the

band-width Optical technologies are the only way to bridge the gap between the need for bandwidth at the network edge and the

Sandra McWilliams, director, fiber cable management, fiber-optic division, ADC:

“The benefits garnered by optical technologies are virtually limitless if its infrastructure is designed to work with multiple technologies and grow as demands grow.”

OPTICAL

OPTICAL

What are the challenges and concerns for

enterprises considering optical technologies?

Mark Fishburn, vice president—business strategy, Spirent Communications, and a member of the board of directors, 10 Gigabit Ethernet Alliance: “September 11th obviously magnified many market trends already in place, but may accelerate business benefits for the high-speed access market.”

Cüneyt Özveren, founder, chairman of the board and CEO, Atoga Systems:

“Given a cyclical economy like the one

we are going through, it becomes very dif ficult to scale the IT departments up and down as the market conditions change A solution for this problem is for the enterprises to outsource their IT requirements.”

huge optical bandwidth capacity already in existence at the

network core As more bandwidth-hungry applications are

de-veloped, the bottleneck between the edge and core will become

more acute For example, end-users with 11-Mbps wireless

LANs are not going to be satisfied with only a 1-Mbps

network connection—especially when efficient high-capacity

fiber-optic networks are just a few hundred meters away

Mullooly: Oftentimes, there is a perception that

opti-cal-networking projects are a bigger task than they actually

are Deploying optical technologies, such as optical ethernet,

allows enterprise network managers to add computing

band-width where it makes the most sense, easily add users to

the network and reduce the need for specially trained IT

staff to manage the network The primary benefit from

optical ethernet is that it increases the available bandwidth,

while relatively reducing the cost of WAN connections—

plus enabling the use of familiar and inexpensive LAN

technologies and protocols, such as VLAN

Enterprise network users and LAN managers may be

un-comfortable with fiber and all its ramifications, such as

mul-timode, single-mode, connector types and distance

require-ments At the enterprise level, there is no need to worry

because the service provider will connect the enterprise to the

fiber network, providing the necessary demarcation point

be-tween the LAN and the MAN, usually as simple as deploying

a media converter between the two As a result, enterprise

users do not see any obvious, discernible difference because

the change from one to the other is totally transparent, with

ethernet running on both sides of the connection

Prior: Enterprise customers have to develop optical

networks that are flexible and scalable as the

technolo-gies improve The near-term challenge will

be—figura-tively and literally—to close the loop, to finish optical

networks and bring benefits of optical technologies to

end-users Business

custom-ers want efficiency,

reliabil-ity and low costs As

de-mand for bandwidth

in-creases, as more complicated

applications come on the

market, businesses will have

to adopt new services in

or-der to stay competitive As

competition grows and

bud-gets contract, there will be

even more emphasis on

find-ing ways to connect enterprise customers to the

thou-sands of miles of fiber already at the network core

McWilliams: Two scenarios exist: renovations of existing

infrastructure and new construction installations The decision

between deploying optical technologies or tapping existing

copper infrastructure hinges on how each solution meets

cur-rent and future requirements, network compatibility, and cost

New construction lends itself to the deployment of fiber The

investment provides a vastly superior long-term solution,

offer-ing maximum bandwidth capability and minimal ongooffer-ing ex-pense Once fiber is deployed, enterprises must then choose optical technologies that best suit network requirements

Özveren: Enterprises have traditionally relied on very

high levels of interoperability Optical technologies have not reached that level yet Enterprises planning to use optical technologies in their networks now should be will-ing to commit to one vendor once they make their choice

Fishburn: As a supplier of performance analysis and

service assurance solutions, we are connected to all the individual competing technologies—DSL, cable modem, PoS, ethernet to 10GbE, wireless technologies and the applications that run over them—MPLS, voice over IP, QoS, Internet applications Certainly, bringing these new products to market faster gives a sense of optimism that the technology can be deployed in a reasonable time frame

Montanaro: One view is “build it and the applications

will come.” The huge pipes that fiber could support would create dramatic differences in the way we do business Imagine what a real-time, full motion, HDTV-quality conference system for meetings and education could do for your business This is perhaps even more compelling after recent events

McWilliams: The business climate is changing Many

busi-nesses are cutting operating costs Videoconferencing, shared data files and online applications are part of the new business paradigm The trend toward a dispersion of employ-ees, decrease in travel and re-liance on online applications has opened the door for inno-vative technologies that allow leveraged assets to produce best value results The benefits gar-nered by optical technologies are virtually limitless if the infra-structure is designed to work with multiple technologies and grow as demands grow Look for DWDMs to allocate specific wavelengths for individual customers; test access to slice main-tenance costs and preserve network integrity; and optimal pro-tection, scalability and reliability to finally reside at the desktop

Özveren: Coupled with quality-of-service guarantees,

band-width allows enterprise applications to be outsourced completely This is a win-win scenario for carriers and

enter-What can be done with the bandwidth that optical will make available?

prises, since—on one hand—enterprises get to spend money

incrementally as opposed to investing in large IT

infrastruc-tures They can adjust the “volume” of services they purchase

as their needs change This is also a win for the carriers, since

it increases the revenue stream they get from their customers

Fishburn: The extension of high-speed core

network-ing, provisioned by metro providers, will be one-half of

the delivery model for data transport The other is the

extension of ethernet-over-fiber services to the last mile

The ethernet in the first-mile initiative—it’s the last mile

for the service providers, but the first mile for the user—

had its inaugural meeting as the IEEE P802.3ah task force

in October The 802.3ae committee has focused on

extend-ing high-speed networkextend-ing at ethernet costs to the 10-Gbps

MAN/core network Now, 802.3ah will focus on low-cost

delivery of high-speed ethernet to the office and residence

Mullooly: Today, most applications do not use all the

available bandwidth delivered by fiber Most companies

find that one T-1 line at 1.544 Mbps is ample for their

needs and, if more is needed, additional T-1s are added

The difference is substantial in comparing the cost of a

T-1 with a T-10-Mbps optical drop at a location While the use

of 100 Mbps or 1000Base-LX is rare for typical enterprise

users, it is suitable for applications where substantially

more bandwidth is required, such as video-on-demand,

high-end multimedia, remote storage networks and vertical

applications, like telemedicine, healthcare and printing

Prior: The obvious applications involve the

conver-gence of voice, video and data The one constant in every

new business application is a need for greater bandwidth

What’s less obvious is the mission of bridging the

explod-ing bandwidth demands of the LAN with the capacity of

the network Certainly, the recent tragedies brought into

focus teleconferencing, storage area networks and disaster

recovery—all bandwidth dependent—and many businesses

now see them as essential

Fishburn: Bringing the low-cost ethernet business model

to the metro network will be a key enabling link from the

edge of the network to the overprovisioned core Key

factors will be price and availability—and will ethernet in

the first mile be deliverable anytime soon

McWilliams: Look for proven technology from a proven

company Today’s turbulent financial environment is

unfor-giving; vendors with exceptional records of quality service

must be chosen Free-space optics (FSO) is a promising, but

relatively unproven, technology Poor propagation conditions,

physical obstruction, and security will always pose realistic

threats to the integrity of the free-space signal Because of

these uncertainties, land-line backup systems will need to be

available, negating any positives gained with the technology

Prior: Experience is invaluable Look for suppliers who

have real customers in the market Ask for references Is it real

or “in development”? The best test is to see if the supplier can

drop ship equipment today Too many suppliers claim general availability, then keep you waiting for two quarters The market will sort this out in a very Darwinian way I would also look for suppliers with strategic partners who can bring expertise and experience to the table beyond their own company’s prod-uct With free-space optics, if a business moves, the equipment can be redeployed, making FSO a much more efficient long-term solution than other technologies

Montanaro: Surveys show that customers value

com-pany performance and technology in the purchase of network gear Most new customers are interested to find out who else uses your gear; therefore, existing customer relationships are very important Regarding free-space optics, we’d recom-mend FSO where short turn-up time and high bandwidth are most important For cases in which higher reliability is most important, we would stick with a land line

Özveren: Most important is reliability Since optical

tech-nologies are relatively less mature, certain technology choices

by some vendors may be less reliable than enterprises are used to The second important factor is plug-and-play capa-bilities A lot of the optical technologies require hand tuning power levels after the equipment is installed, and any changes typically require retuning the network New technologies are becoming available that make DWDM plug and play

Montanaro: All of the above, though I’d include inertia,

also In the U.S., we have over 190 million access lines A ball that big takes time and a lot of effort in the three areas identified to start moving I’m afraid that progress sometimes takes longer than the media or the technologists have the patience for within the access arena DSL is a good example

Özveren: Technology is not a barrier, since some vendors

have shown that this can be done with the equipment that they have been shipping Economics is typically not a barrier either, since a converged device which incorporates multiple devices will typically cost less than the combined cost of all those devices, and result in less operational expenses, since it

is much easier to manage one box The barrier is really politics Enterprises and carriers have developed separate or-ganizations internally for different layers of the network A converged solution requires buy in from all these in order to

be accepted into the network Faced with financial challenges, most enterprises and carriers are reorganizing to remove mul-tiple layers Once these layers are removed, it will be much

David Montanaro, CEO/chairman of the board, NEC Eluminant Technologies Inc.:

“One view is ‘build it and the applica-tions will come.’ The huge pipes that fiber could support would create dramatic dif ferences in the way we do business Imagine what a real-time, full motion, HDTV-quality conference system for meetings and education could do for your business.”

What should be considered when choosing

an optical supplier? When deciding between

hard-line connections vs free-space optics?

What is preventing converged networks:

technology, politics, economics?

Most large U.S cities have one or more

optical metro networks Will more networks

be built in these Tier 1 cities? When can

most Tier 2 and 3 cities expect optical

ser-vice? How will the growth of these networks

impact costs to the end-user?

and currently, the unsteady market and a reduction of competitors has allowed service providers to remain cau-tious about deploying optical metro networks

Montanaro: You would be hard pressed to find a U.S.

town of more than 25,000 that did not have some type of fiber deployed in the ground Chances are it belongs to the local ILEC and is being used to serve digital loop carriers,

or maybe a large business Trouble is, there may not be enough businesses to attract competitors for the ILEC

Mullooly: Supply and demand will rule the

prolifera-tion of networks In cases where fiber is not already in-stalled, the upfront cost to lay these networks is exorbitant

In most Tier 1 cities, a fiber glut exists Less expensive, faster and more flexible than traditional telephone networks, optical ethernet provides the bandwidth and the distance that most users desire Where the fiber network resides close to the enterprise network, fiber to the business makes more sense, with service providers using media converters to serve as the optical access point to connect the LAN to the MAN In some Tier 2 and 3 cities, fiber networks are being deployed today because of specific demand and an existing infrastructure to support the network Most Tier 2 and 3 cities do not contain existing networks, which reduces the

need to deal with network integration issues Service pro-viders such as EtherLECs are investigating the possibility of building their optical metro networks in these cities that will provide service at a competitive price In those cases where the use of fiber is cost-prohibitive, it makes more sense to deploy microwave or wireless for the last mile

Prior: The rollout of optical networks is continuing, despite

the much-publicized slowdown in the market History has shown that short-term economic forces won’t stop the natural progression and adoption of technologies that really make sense With more competition and advances in long-haul tech-nology, more small cities will soon receive optical capabilities The problem will be finding cost-efficient and fast ways to get that bandwidth to end-users and to complete networks where it will not be economically feasible to lay fiber That’s where free-space optics comes in If the networks can reach them, end-users will be the biggest beneficiary of this optical growth Not only will they get the bandwidth they crave, the services will become increasingly affordable

Lawrence Prior III, CFO, LightPointe:

“History has shown that short-term economic forces won’t stop the natural progression and adoption of technologies that really make sense.”

Brendan Mullooly, director of European operations, IMC Networks:

“Oftentimes, there is a perception that optical-networking projects are a bigger task than they actually are

At the enterprise level, there is no need to worry because the service provider will connect the enterprise to the fiber network.”

easier to remove the layers in the network, as well

Prior: Conflicting standards, self-interests and cutbacks

in budgets have certainly slowed the rollout of all-in-one

networks But convergence is happening Recently, in

Manhattan, we experienced firsthand that the demand is

there One of our partners actually gave up its own VoIP

equipment to help out a customer who was looking to

restore its network using FSO links

Mullooly: With converged networks, technology definitely

plays a role because it is difficult to integrate a variety of

different protocols all into one network Coupled with the

complexity of different vendors’ respective hardware and

soft-ware solutions, it becomes an expensive and time-consuming

proposition to achieve true convergence Optical ethernet

elimi-nates many of the challenges because of the support of the

standard by many vendors and their solutions

The economic landscape is changing with the

advance-ment of metropolitan optical ethernet networks The

pro-liferation of ethernet service providers in Europe and the

U.S has further broken down this barrier These ethernet

service providers, EtherLECs, have built their networks

from scratch by renting fiber from other providers using

a simple architecture The proposition of EtherLECs is to

provide 10 Mbps or 100 Mbps at the same price of a

typical T-1 As a result, EtherLECs build lower-cost

net-works that make efficient use of the MAN bandwidth

The provisioning of optical ethernet connectivity to

corpo-rate customers is now well established The speeds offered—

10, 100 or even gigabit—can be utilized by larger customers

for hosting multiple servers, SANs or even internal

voice-over-IP traffic Applications that can utilize the bandwidth

provided by optical connectivity are well established

McWilliams: Their deployment depends heavily on the

well-known theory of supply vs demand Service

provid-ers will hesitate to build metro networks until demand for

optics intensifies and competition poses a significant

chal-lenge When this happens, end-users will reap the

ben-efits and avoid much of the costs It is a waiting game,

Reprinted from Communications News, November 2001 Copyright © 2001 by Nelson Publishing Inc • www.comnews.com