Re: Fiber Into Last Mile / PON / Metro DWDM
"CSCO will be squeezed out of the core and will be playing in the edge. Good for CSCO. Very big business here: Cerent and Monterey will coming very handy on the metro loops which will require somehting more than SONET/SDH.
elmatador and Thread,
Nice little post you did. The article below explains in more detail, you SONET/SDH comments.
From the article: "If DWDM technology is being used to provide virtually inexhaustible capacity in the WAN, then metro networks, where linked SONET rings now dominate, will also have to be upgraded as part of a solution to eliminate the bandwidth bottleneck."
I know the article is very long and I was going to try and highlight a few key points. But there are just too many. All of the below should be of great interest to telecommunications infrastructure investors as it attempts to predict the future of the Last Mile and the MAN. I thought I would cut&paste the entire article for future reference.
BTW, there is a paragraph on T's, "Lightwire," system being tested in Salt Lake City. We all discussed this upstream in quite some detail a ways back.
MikeM(From Florida)
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Optics Explode
The next wave of optical network equipment promises to take the technology into the last mile
Sam Masud, Senior Technology Editor- There's a bandwidth glut; there's a bandwidth drought; there's a bandwidth glut. Depending on when you ask the question, all of these statements are true. Dense wavelength division multiplexing (DWDM) is pumping up the capacity of the long-haul network while Gigabit Ethernet is firmly ensconced in the enterprise LAN. And the LAN is about to get a major boost: Work is underway to release the first draft of a 10-Gbps Ethernet specification next September and to have a completed standard by March 2002. Although the year 2005 is still distant, 3Com predicts that more than one million 10-Gbps Ethernets will have been shipped by then. But voice-centric SONET rings, which are expensive to scale, dominate the metropolitan and access networks that act as the bridge between the enterprise customer and long-distance service provider. "There are places you could get an OC-3 turned up in a few hours and there are places you couldn?t get it in six months," said Mike O'Dell, UUNet's vice president and chief scientist, expressing the frustration of many service providers. "It annoys everyone, most of all our sales guys, because we have installation service level agreements (SLAs) that give customers free money if we don't hit deadlines. But you can push things only so far."
The spiraling demand for bandwidth suggests that some service providers will hasten to adopt optical technology to offer better, faster services at lower prices. Already some service providers are viewing SONET more as a protocol than a piece of networking equipment, prompting Forrester Research to predict that by 2003 the technical hurdles will be overcome and optical gear will replace SONET for new equipment purchases. "ISPs and CLECs will be early adopters of this new optical product, particularly the CLECs that are leasing fiber because they'll want to squeeze more out it," said Dana Cooperson, senior analyst at RHK.
A new breed of vendors is now committed to bringing optical networking to the last mile. Using passive optical networking technology that permits fiber networks to be built without costly active electronics, companies like Quantum Bridge, of North Andover, Mass., and Sunnyvale, Calif.-based LuxN are offering last-mile solutions. "A major distinguishing feature of a passive optical network (PON) is that there is a passive power splitter/combiner that sits in the outside plant, performing an optical broadcast to multiple locations, similar to cable TV signal distribution," said Eugene Park, co-founder and product marketing director of LuxN. Because the upstream path from end users returns on the same path, typically a time division multiplexing (TDM)-based upstream method is used, [thus] limiting the overall bandwidth links on the PON. One advantage of PON is that depending on where the optical splitter is located, there could be substantial savings in the amount of fiber used."
Michael A. Viren, founder and former chairman of 2nd Century Communications, a Tampa, Fla.-based CLEC, believes these new equipment vendors could change the dynamics of the CLEC business. "The prices of the new edge devices, if they are low enough, could reconstruct the CAP business again. That's the part I get excited about. Using passive optics to really lower the cost of providing the last mile with fiber. Today, even CAPs will lease a T1 [from the RBOC] because it's not worth going into a building if all you can sell are three T1s. But by using passive optics to really lower the cost of providing the last mile with fiber, CLECs are going back to the old CAP model, when you could make money selling a half-dozen T1s before the RBOCs lowered their prices."
PON Players
LuxN is focused on delivering high-bandwidth services to the customer premises. LuxN's solution consists of equipment that resides at the central office (CO) or point of presence (POP) and a small footprint unit located at the customer premises. "Our product portfolio consists of what you might think of as an optical DSLAM and an optical channel service unit. It provides a clear channel stream from the customer premises to the CO," said Paul Strudwick, LuxN's vice president of marketing. The LuxN solution delivers a minimum connection of OC-3 over a fiber pair. LuxN's ColorValve technology allows either the carrier or the customer to incrementally upgrade bandwidth. The company also plans to roll out a multitenant or multi-application version of the product, with each application or tenant served by a fiber pair or, if the economics dictates, by a wavelength.
The Quantum Bridge solution consists of an optical access switch that resides in the hub location and an optical terminal located at the customer premises. The company's dynamic wavelength slicing protocol allows the architecture to fan out each wavelength in a way that it can serve multiple customers. Depending upon a customer's needs, service providers can provision 1 Mbps to 100 Mbps of bandwidth to each remote terminal. The company claims its solution offers substantial savings when compared to providing transport services over a TDM network or an ATM network in terms of equipment cost per customer.
Bandwidth solutions like these are appealing to Sameer Siddiqui, senior network architect in Sun Microsystems' MIS shop. The company has been lab testing products from a start-up that would allow it to replace the tens of T3 lines it uses to move traffic between Gigabit Ethernet switches at its campus sites in the Bay Area with an optical network. Although Sun is keeping its options open, the product in trials would provide a managed wavelength to transparently support any transport protocol such as Gigabit Ethernet, ATM or Fibre Channel. Siddiqui plans to do a pilot between the company's Menlo Park and Newark sites and later extend the solution to other sites. "I think of this product as an optical modem," Siddiqui said. "We considered getting SONET service last year but it turned out to be pretty pricey and the deployment time was way too long. Besides, we haven't had such a great experience provisioning SONET."
Although LuxN product literature proclaims that "The Optical Renaissance has Begun," such a renaissance presupposes the deployment of fiber to or close to the customer. Estimates vary on how close customers are to fiber today or will be in the near future. Vertical Systems Group estimates that 76 percent of midsize businesses are within one mile of fiber. The Federal Communications Commission notes that between 1995 and 1998 the amount of fiber miles deployed by CAPs grew more than 500 percent.
AT&T, having spent over $100 billion to acquire cable television companies Tele-Communications and MediaOne, is only too mindful of getting the fiber closer to the subscriber in order to deliver a richer set of voice, data and video services than those currently supported by the hybrid fiber coax network. AT&T's LightWire system, which is currently being piloted in the Salt Lake City area, extends the fiber closer to subscribers. According to AT&T, it supports all current services (video, data, telephony) and provides an envolution path to very aggressive bandwidth. LightWire, the company claims, expands the total bandwidth of the coax plant to 1 GHz, triples the upstream bandwidth and, over time, will increase upstream bandwidth by a factor of 10. Additionally, it improves network reliability, reduces the number of active components in the network by 60 percent?consequently cutting power consumption in half?and supports all industry standards while future proofing the network for emerging service demand.
Minneapolis-based Optical Solutions already has a product in service for delivering data, voice and cable TV over fiber called FiberPath The fiber-to-the-home solution requires no electronics between the headend and the subscriber, who might be five miles or more from the headend.
From a splice point in the field, the company's solution requires a fiber pair to each home, with each splice point serving up to 32 homes. FiberPath supports up to six phone lines, both NTSC (135 channels) and digital CATV, and data services that the service provider could upgrade in 64-kbps increments to a maximum of 10 Mbps. The system could also support meter reading and security services. Under FiberPath, all services are accessed by the subscriber from a network interface device that Optical Solutions calls a universal demarcation point (UDP). "The UDP, which is AC-powered with battery backup, resides on the side of a home. It takes in the fiber signals and transfers them through the appropriate home wiring," said Bob Lund, chief technology officer for Optical Solutions. "We have plans to deliver OC-3 service through the same infrastructure without touching a thing," Lund said.
The FiberPath solution is already being used by All West Communications of Kamas, Utah; FutureWay Communications of Toronto; and Rye Telephone of Colorado City, Colo. Rye Telephone has purchased FiberPath to serve a 4000-home development with each home connected by a six-fiber drop. "The decision is pretty straightforward when you compare networks," said Jeff Starcer, chief engineer and plant manager for Rye Telephone. "A totally passive optical network to the home will carry our company and customers well into the future."
Metro strategies
While these players are focused on a last-mile solution, other optical equipment vendors such as Sycamore Networks, Kestrel Solutions and Chromatis Networks are seeing opportunities in the metropolitan network. Millennium Optical Networks, a Manhattan-based CLEC, has deployed Sycamore's SN 8000, a family of intelligent optical add/drop multiplexers that adapt, switch and route multiprotocol wavelengths so that a user can come into the network at any point and exit at any other without SONET termination gear. Millennium has deployed the SN 8000 in carrier colocation facilities in New York City to provide high-bandwidth carrier-to-carrier services on an as-needed basis. "We're starting out with the carriers because they are the high-volume customers. Their criteria for purchase is price, performance and [time to] installation," said Peter Tierney, president of Millennium, which currently is using leased fiber facilities but also plans to lay its own fiber. Although Millennium currently offers only OC-48 service, the company expects to soon have Sycamore?s new line cards that support OC-3/OC-12 services. "With the SN 8000, my cost for provisioning a channel is lower. Speed to provision is a problem in the carrier market today because it takes six to eight weeks to deliver an OC-12, and even at the OC-3 level it could be a long, drawn out time. An OC-48 could take six weeks to six months," Tierney said.
If DWDM technology is being used to provide virtually inexhaustible capacity in the WAN, then metro networks, where linked SONET rings now dominate, will also have to be upgraded as part of a solution to eliminate the bandwidth bottleneck. Although the metro DWDM is a recent phenomenon, metro systems from DWDM vendors that have established themselves in the long-haul market are beginning to be accepted by service providers such as America Online, Cable & Wireless and Metromedia Fiber Network. AOL selected Ericsson's ERION system last summer for a 140-km network in Washington, D.C. Cable & Wireless has two metro DWDM networks up and running and plans to install Ciena's MetroWave product in about two dozen markets. "Metro DWDM is lower in cost than putting in more fiber and allows quicker time to market for services," said Wesley Ford, transmission systems planning director of Cable & Wireless, which typically installs the DWDM equipment in carrier hotels and RBOC colocation facilities, since about 80 percent of the company's market consists of services sold to other carriers and ISPs. Currently, Cable & Wireless is running six 2.5-Gbps channels but expects to increase capacity by as much as nine to 12 channels in some markets. Plans also call for increasing channel speed to 10 Gbps during the first half of next year in some of those markets. "Right now we are getting requests for (155 Mbps) OC-3 and (622 Mbps) OC-12 services, and some inquiries for OC-48, but we expect to start seeing firm orders for OC-48 within the next 12 months," Ford said.
White Plains, N.Y.-based Metromedia Fiber Network has targeted certain tier one markets for building a fiber-rich local loop. According to Ron French, Metromedia?s vice president of commercial marketing, Metromedia is putting in 864 strands of fiber in each cable and laying multiple conduits within each build to support additional fiber. Although the company's primary business is leasing dark fiber (in October it announced a $500-million dark-fiber deal with Bell Atlantic and a similar $300-million dark-fiber agreement with WinStar Communications), Metromedia also offers managed optical services for enterprise customers using Nortel's 32-channel OPTera metro DWDM technology and Cisco Systems? Catalyst switches for a managed Gigabit Ethernet service. "If an enterprise customer wants to run multiple protocols, such as Gigabit Ethernet or (IBM) ESCON, we can support those protocols. For the user, adding a service becomes a plug-and-play capability," French said.
Although vendors often pitch these DWDM systems to the metro or interoffice market, UUNet's O'Dell pointed out that the CO is no longer the only place where the demand for local bandwidth is increasing. "COs are historical artifacts where you used to have a lot of telephony hardware owned by the phone company. Now there are a lot of places where there's a whole pile of communications hardware. Sometimes these are called POPs, cable headends or whatever. If a customer has an OC-48 from me, that [customer] might as well be a CO because I've got the same tactical and strategic issues of getting bandwidth to the customer. The metropolitan network capacity has been burned through at a rate that is nothing short of terrifying to traditional network planners, and that's one of the reasons customers want to colocate their Web farms in our infrastructure: They want to be able to provision additional capacity quickly," said O'Dell. UUNet is building a dedicated fiber network and will use DWDM technology for fiber gain. In some places UUNet will own the fiber, in other places it will be a managed service. However, O'Dell declined to disclose whether it would own the DWDM equipment.
While the advantages DWDM offers by delivering a forecast-tolerant network are obvious, the systems are not going to be cheap, even in their metro versions. This is partly because DWDM systems require a pricey optoelectronic conversion at each node to add or drop a channel, a capability likely to be used more often in the metro area given the dynamic pattern of the traffic in this network segment. Equally or perhaps even more importantly, some metro DWDM might consume an entire wavelength (a situation referred to as burning a wavelength) instead of packing multiple services until the channel is full.
According to Ted Rado, marketing director for Mountain View, Calif., start-up Alidian, this is because many metro DWDM vendors products are made up of transponders, which take in an optical signal of a specific wavelength (typically 1310 nm), convert it to an electrical signal, and back again to an optical signal of a different wavelength (1550 nm) for long-haul transport. "They take in an OC-3 ATM service from a piece of customer premises equipment, for example, and transpond it onto a wavelength that their system can transport. The disadvantage of this system is that it takes many wavelengths to transport many services. Each wavelength can take in a service, but when you want to add another, it takes another wavelength," Rado said. Alidian is expected to announce what it calls an Optical Service Network solution that will not only ensure that wavelengths are properly packed, but also are service aware. For example, the solution recognizes whether certain traffic has an associated ATM QoS or multiprotocol label switching (MPLS) tag. An Alidian network will also be able to switch individual services on and off at wavelength add/drop points.
Other vendors also are seeing shortcomings in metro DWDM products and are promising to deliver more granular systems for the metro and access markets. Qeyton Systems, a Swedish start-up that will open a U.S. office, will soon unveil a DWDM system that will go into beta trial with a large Swedish ISP as well as a U.S. ISP. The Qeyton solution is intended for the interoffice ring as well as lower bandwidth requirements. Qeyton's hub node will offer per-channel upgrade to a maximum of 48 channels (the initial product will support up to 16 channels); a collector node will provide a single channel back to the hub node. The company boasts that it will offer the fastest per-channel optical protection switching?less than 1 ms.
When it comes to the SONET-vs.-DWDM argument, Chromatis Networks, of Bethesda, Md., has taken the middle ground via its Selective DWDM technology. The Chromatis product allows operators to start out with a shared 1310 nm ring (short reach 1300 nm lasers used in SONET are cheaper than 1550 nm lasers), which might be used for connecting DSL access muxes (DSLAMs) to the CO. As the bandwidth needs of a particular DSLAM site increase, the service provider could drop a new wavelength to that site and perhaps someday upgrade each site to support a wavelength. A site needing to access the shared 1310 nm ring would do a simple pass-through of the 1550 nm ring.
With the Talon MX product Kestrel Solutions is expected to announce in Q1 2000, the company has added yet another wrinkle in the metro DWDM landscape with its frequency division multiplexing (FDM) technology. The Kestrel product takes in a number of signals (up to OC-48), converts them to electrical signals and then combines them using FDM. It then does another optical conversion that, in effect, allows multiple FDM channels to be carried on a single wavelength, thus enabling a 10-Gbps DWDM channel to handle up to 64 OC-3 channels. Kestrel's approach allows any FDM channel to be added or dropped at any node. The Kestrel solution supports the full 3Rs (reshape, regenerate and retime)something all DWDM networks do every so often to clean up signals. Although the 3R-process is expensive in DWDM networks, Kestrel claims to have found a way around the problem with a single conversion for all channels, in contrast to DWDM, which requires a conversion for each regenerated wavelength. "Traffic from each user device, for instance a router, would occupy one FDM channel; a single input could also be dispersed across multiple FDM channels," said Dawn Hogh, Kestrel's vice president of marketing.
It remains to be seen whether these new optical networking products will be adopted as quickly in the metro/access network in the way that DWDM technology has become popular in IXC networks. A huge amount of capacity in long-haul networks is driving down the prices of long-distance services. Meanwhile, the metro/access network remains a bottleneck that probably cannot be addressed by a TDM technology like SONET. This being the case, it's a good bet that some service providers, sooner rather than later will take the plunge into relieving the bandwidth blues in this segment of the network via a technology that has already proved itself in the network core.
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