Intelligent access now may be winning as the service provider networking buzz-phrase of the 1990s, judging by the new products--and the emerging new classes of products--touted during the SUPERCOMM '99 exhibition in Atlanta. The goal of the new gear: build an access device at the service provider-customer boundary intelligent enough to manage every kind of service for every customer over one pipe.
While the majority of technology providers agree that service provider access networks must continue to accommodate an alphabet soup of connection protocols, an increasingly important role for asynchronous transfer protocol (ATM) switching and multiplexing provided a subtext for many a SUPERCOMM announcement.
Indeed, multiple categories of new products emphasize the first-time integration of ATM technologies. Among the ATM-driven product and partnership announcements:
* A new class of "data aware" fiber optic gear from ADC Telecommunications Inc., Minneapolis; Atmosphere Networks, Inc., Cupertino, Calif.; and Omnia Communications Inc., Marlborough, Mass., that combines ATM service management with synchronous optical network (SONET) connectivity.
* Demonstrations of "class-independent," computer server-based telephony switches designed to complement, and eventually replace, legacy Class 5 and Class 4 time-division multiplexing (TDM) telephony switches with ATM switching.
* The debut of the ATM Local Telephony Alliance (www.altainfo.org), a group of six manufacturers (Advanced Switching Communications Inc., Vienna, Va.; Convergent Networks Inc., Tewksbury, Mass.; Mariposa Technology Inc., Petaluma, Calif.; Siemens AG independent subsidiary Unisphere Solutions Inc., Burlington, Mass.; VINA Technologies Inc., Fremont, Calif.; and Woodwind Communication Systems Inc., Frederick, Md.) and one competitive local exchange carrier (CLEC) (2nd Century Communications Inc., Tampa, Fla.) formed to shepherd development of uniform standards and practices for local ATM-based voice switching.
* Proliferation of a new class of customer located integrated access devices (IADs) and central office (CO) multiservices switches employing ATM quality of service (QoS) and service multiplexing functions from Cisco Systems Inc., San Jose, Calif.; Lucent Technologies Inc., Murray Hill, N.J.; Newbridge Networks Corp., Herndon, Va.; Nortel Networks, Richardson, Texas; and other manufacturers.
* Introduction of ATM adaptation layer 2 (AAL-2) voice-compression technology to maximize efficiency of multiline, packetized voice transport over digital subscriber line (DSL) and other broadband access media.
"ATM concentration at the point of presence (POP), then ATM switching in the CO become the core gateway into all wide area networks (WANs)," says Michael Viren, founder and chairman of 2nd Century, which announced a $30-million ATM switch contract with Convergent Networks at SUPERCOMM. "With ATM, we get one switching fabric, one protocol and one pipe, instead of five different networks for long distance, local public switched telephone, frame relay and the Internet."
Not everyone agrees. Although new carriers such as 2nd Century have an opportunity to unify services around a single technology such as ATM, most service providers must continue to accommodate multiple protocols, says Jim Dolce, president and founder of Redstone Communications Inc., which was acquired by Unisphere earlier this year.
"As a private company, Redstone was touting next-generation IP (Internet protocol) technology as synonymous with QoS," Dolce says. "New-generation IP products have caught up with QoS for carriers like Qwest [Communications International Inc., Denver,] and Level 3 [Communications Inc., Omaha, Neb.,], who want to build IP transport because they believe it's lower cost, while carriers like Williams [Tulsa, Okla.,] have embraced ATM as a competitive edge against Qwest and Level 3 who have to match Williams' quality of service capability."
ATM and QoS
Most advocates of ATM in the access network argue that it answers customer urgency to control QoS for various types of mission-critical and delay-sensitive services such as voice. In development for two decades, ATM also was designed to accommodate data, voice and video services over a single physical connection. And, because it dynamically allocates bandwidth to each service on demand, ATM can enable "over-subscription," or circuit sharing, thereby accommodating more users than permanent TDM circuits dedicated to each user.
"You hear a lot about telephony over IP, but we really believe ATM is necessary to build a better economic model for use in the local loop," Viren says.
According to Karl May, president and CEO of Convergent Networks, local telephony carriers can build networks at one-twentieth the cost of Class 5 switches. Per CO, the cost difference can be between $6 million for class switches and only hundreds of thousands of dollars for ATM switches. "Unlike Class 5 switches, which are based on proprietary hardware, ATM switches are based on standard computing platforms, which are subject to Moore's Law [the halving of the cost of computer processors every 18 months] and therefore drop in cost quickly," May says.
By extending ATM multiplexing and ATM-based circuit emulation services (CES) out to remote POPs, "a CLEC can create a new serving area for $10,000 to $12,000," a cost-effective alternative to multimillion dollar TDM switches or $200,000 ATM switches, says Mark Kaplan, director of marketing for Advanced Switching Communications (ASC), Vienna, Va. CES support in ASC's RBOX 4000 switch (with up to 336 T1 capacity) can support low-cost concentration of both data and business telephony over integrated access lines, he says.
ATM also is invading SONET equipment. Whereas TDM-based SONET add/drop multiplexers (ADMs) force data packets into fixed-size channels--whether or not a given data session fits the channel's data rate. A new class of ADMs can treat data traffic differently. These ADMs integrate ATM switching and IP routing to aggregate traffic over SONET regardless of channel size. This reduces the number of ports needed on ATM backbone switches and thereby reduce service provider infrastructure costs.
Priced starting at $30,000, Omnia Communications' AXR-500, ATM-based ADM can cut costs by more than two-thirds, says Douglas Faber, director of product planning and marketing. An AXR-500 at the CO can concentrate and groom data ATM virtual paths off to separate backbone networks, sending TDM traffic to the PSTN and voice over IP (VoIP), voice over ATM and data traffic to packet-switched backbones.
Similarly, Atmosphere Networks, Cupertino, Calif., which announced the sale of its ATM-based ADMs to Vancouver, Wash.-based carrier GST Telecommunications Inc., introduced its Full Service Node 1200, which "can deliver 100-megabit-per-second service over [622mbps] OC-12 for the same price that conventional ADMs can deliver T1 over [155mbps] OC-3," says Marketing Vice President Alex Dobrushin. "So we've increased access speeds, but kept the economics the same."
GST and Williams also are early buyers of Alameda, Calif.-based Ascend Communications Inc.'s GX 250 Multiservice Extender, which is designed to use ATM to bypass both SONET ADMs and voice digital cross-connects altogether, supporting both TDM and ATM and "could be used to transport circuit voice to the ATM core," says Product Marketing Manager Dennis Fiore.
Now extending ATM even deeper into the access network, all the way to the customer premises, are IADs and multiservice DSL devices.
"ATM underlies DSL, so everybody's comfortable with that, and CLECs want to change the access cost model by using broadband," says Scott Bell, Nortel Networks' director of strategic marketing for access network products. "If the customer is data only, frame relay is fine, but when you add voice, you hear customers say they want QoS and verifiable service level agreements (SLAs), and they say that frame is good, but ATM is better."
Consequently, to support voice over broadband DSL access, Nortel Networks has invested in Jetstream Communications Inc., Los Gatos, Calif., and introduced AAL-2 support to its Universal Edge 9000 multiservice access switch and to its Passport 4740, a $5,000 IAD that extends ATM from the Passport 15000 CO cell switch to customer sites. Still, the Universal Edge 9000 also supports legacy TDM feeds, as well as IP and ATM integrated services feeds, from customers.
As part of Nortel's Succession Networks architecture, the Passport ATM switches are aimed at "carriers who want to cut costs by collapsing Class 5 and 4 switches into one layer and connecting both data and voice traffic directly into ATM networking," says Rod McPherson, vice president of next-generation networks. "Succession represents the distribution of the ATM fabric to distribute both access and call control."
As part of its own efforts to unify voice and data via ATM, Alcatel USA, Plano, Texas, has partnered to integrate Jetstream's voice over DSL (VoDSL) gateway with Alcatel ATM switches and new ATM-based symmetric DSL (SDSL) systems introduced at SUPERCOMM. Through its purchase of Assured Access, Alcatel also debuted at SUPERCOMM a Universal Access Gateway and Service Management System gateway controller. Combined with Alcatel PSTN signaling gateways, the DSL and multiservice gateway products could spell the end of redundant TDM and packet networks for Alcatel customers. "We think it creates a way for us to help data CLECs to get into voice and for voice CLECs to get into data," says Jay Fausch, senior director of business development for Alcatel's DSL lines.
Like Nortel, Lucent Technologies used the SUPERCOMM forum to introduce an ATM-based IAD, the PacketStart AC 20. Also employing the ATM Forum's AAL-2 standard for voice compression, the AC 20 can enable a service provider to expand T1 capacity from 24 voice channels to 200 voice channels.
According to David Haas, director of customer located equipment (CLE) for Lucent, urgency for the ability to prioritize traffic and to control QoS for each service type drove Lucent's decision to employ ATM. IP products that use the Internet Engineering Task Force's (IETF's) emerging differentiated services (DiffServ) standard to prioritize traffic and the multiprotocol label switching (MPLS) standard to supply ATM-like control of end-to-end paths through service provider networks "remain probably a year out," Haas says. "In the interim, ATM provides the ability to prioritize traffic without pre-standard MPLS or DiffServ technologies."
In fact, Lucent's AC 20 IAD for the customer site ($10,000) and higher-density AC 230 multiservice access switch for the CO ($74,000) borrows a page from DiffServ, applying a Lucent Adaptive Queuing Management algorithm to create 10 class-of-service (CoS) priority levels on top of ATM's ability to deliver constant-rate, variable-rate and available-rate QoS services. "We're telling carriers not to provision a second T1 line to carry growing data traffic, but rather to put this AC 20 box in to expand the first T1's capacity eight-fold," Haas says.
Cisco Systems also aims to push its ATM access technology closer to customers. In May, Cisco announced a $100 million contract to supply a combination of IP and ATM technologies to Convergent Communications Inc., a Denver-based CLEC committed not to deploy Class 5 switches. At SUPERCOMM Cisco also introduced ATM QoS and frame relay-to-ATM interworking in its DSL products, as well as partnering with ATM-based VoDSL gateway makers CopperCom Inc., Santa Clara, Calif., and Jetstream.
The Cisco 6400 service gateway integrates an ATM switch with up to seven IP routers. "You could start with the 6400 purely as an ATM switch, then add router engines as your customer demand grows," says Dave Lively, DSL product manager for Cisco.
Indeed, some would say that if Cisco, king of IP routing manufacture, has made room for ATM technologies in its product lines, ATM must be key to next-generation networking.
"In a lot of service provider networks, it will be both IP and ATM, and the real emphasis is on the shift away from TDM to packet networking," Lively says. "Cisco is being misperceived as an IP-only company. IP is a powerful technology for enabling services, but ATM is an important technology in many networks, and the critical thing is to make sure you can run all the services over those networks."
Counterpoint
In contrast, some manufacturers emphasize the inefficiencies of converting multiple protocols, including IP, TDM and frame relay, to the ATM fixed-length cell format, as well as the dangers of locking access networks into a single, unifying technology which may be outrun by future advances.
At SUPERCOMM, ADC Telecommunications demonstrated Opera, a multiservice access switch for the CO. It employs a generic matrix switching fabric, rather than an ATM switching fabric. "The fabric doesn't care whether the traffic is ATM, TDM or an XYZ technology that comes out next month," says Barry Kantner, director of West Coast operations for ADC's business broadband group. "With technology-independent access, I can take advantage of whatever wide-area access is available, regardless of whether it's channelized (TDM) or unchannelized (ATM or IP).
"ATM, even IP, will eventually become obsolete, so you don't want to build your service intelligence around a single technology," Kantner says. In the meantime, he adds, "why am I converting TDM to ATM and back again to interwork ATM or any other fabric with every new access protocol?"
Further, customers can couple the Opera switch with ADC Kentrox's Service Point IAD, which accepts TDM, IP, frame relay or ATM at the customer premises and enables a variety of service provider access options. "In the real world, each remote site or branch office connection may be different," says ADC Kentrox Product Marketing Director Scott Sarnikowski. "Where service regions offer ATM, you can buy ATM, and where service regions offer frame relay, you can buy frame relay, so there's no need to place a bet on one technology like ATM over DSL."
