It may go down as one of the wonders of marketing history that frame relay access services have continued to grow despite offering only petite and extra-large bandwidth sizes and nothing in between. Now, that lack of choice on the frame relay access capacity rack stands on the verge of disappearing, thanks to the arrival of equipment based on a new standard.
Standardized by the Frame Relay Forum last September as specifications FRF.15 and FRF.16, otherwise known as the Multilink Frame Relay (MFR) protocols, MFR was developed to allow carriers to bond multiple 1.5mbps (T1) access lines, creating a bundle of T1s that act as a single pipe of 3mbps, 6mbps, 12mbps and so on.
By March, leading frame relay carriers including Intermedia Communications Inc. (www.intermedia.com) and PSINet Inc. (www.psinet.com) began to announce large purchases of equipment to roll out MFR services.
"Fractional T1 services expanded the frame relay market before by answering more customers' needs, and now fractional T3 services will do the same," says Al Binford, senior vice president and chief marketing officer for Intermedia. "There are many folks out there with 4 megabit or 6 megabit requirements that have not been served well until now."
No wonder MFR is catching on fast. By providing "NxT1" capacities, it fills a huge gap between a single T1 copper loop access and the next largest standard WAN capacity available--45mbps T3, a pipe 30 times larger than T1 that requires fiber optic connection and often costs five to 10 times as much as a T1. Whereas a T3 connection might typically cost end users $15,000 per month, vendors predict that MFR services in the 3mbps to 6mbps range will be priced at $2,000 to $5,000 a month and be more precisely sized to the end-user's actual needs.
Frame relay revenues stand at more than $8 billion worldwide. Going forward, MFR will help frame relay "scale to support the astounding number of new applications that enterprises are introducing into their networks," says Andrew Cray, senior analyst for industry researcher Aberdeen Group Inc. (www.aberdeen.com).
Vendors of CO frame relay aggregation systems leading the MFR charge include Advanced Switching Communications Inc. (www.asc.com) and Tiara Networks Inc. (www.tiaranetworks.com). Additionally, frame relay backbone switch makers, such as Lucent Technologies Inc. (www.lucent.com) and Nortel Networks Corp. ( om), are integrating MFR into their switches. CPE makers, including Paradyne Networks Inc. (www.paradyne.com), are doing the same.
Responding to MFR's competitive promise, PSINet announced on March 8 that it had selected Tiara's new Series 7000 Frame Switch for distributed PoPs and Series 1000 Multi-Megabit Access Concentrator for customer premises to launch Aggregated Virtual Circuit services via T1, NxT1 and T3 connections. On March 13, Intermedia announced it had selected ASC to provide MFR-capable MultiStream technologies to similarly enhance the bandwidth flexibility of Intermedia's 50,000-node frame relay network.
"With ASC, we now have multiple ways to deliver data bandwidth, particularly down-market," says Binford. Those ways include MFR as well as a similar T1-bonding standard for ATM links known as Inverse Multiplexing for ATM (IMA), which also is incorporated in ASC's MultiStream equipment. Each MultiStream port is software configurable for MFR or IMA.
With ASC's remotely managed, 12- to 24-port stackable "pizza box" CPE, along with its A-4000 aggregator (accommodating up to 336 T1s) distributed across small PoPs that feed larger central PoPs, Intermedia will reduce expensive truck rolls and "provision new bandwidth and services remotely within hours, rather than days or weeks," Binford adds.
Having recently completed a wide-scale upgrade of its ATM core network, Intermedia can feed both aggregated frame relay and aggregated ATM traffic into its backbone. According to Binford, ASC's equipment will become the "prime gear facing into Intermedia's network," complementing not only ASC's CPE, but also a range of integrated access CPE from other vendors. They include Carrier Access Corp. (www.carrieraccess.com), Nortel and VINA Technologies Inc. (www.vina-tech.com), which together cover a range of scenarios for end users who may or may not already employ PBX equipment for voice traffic.
Intermedia will use the increased flexibility of MFR initially to strengthen what it believes is a leadership position in private data and corporate Internet access services, then integrate voice services into its data services over time.
Although ATM and IMA, combined with ASC's QoS capabilities, can be used to offer converged voice and data services, "frame relay and MFR are excellent for data-specific applications, such as high-speed Internet access," Intermedia said in a statement at the time of the deal.
That data-centric approach increasingly will include interworking between frame relay and IP VPN technologies, says Binford, who calls the marriage of IP VPNs and frame relay a natural. The reason: IP lowers private data network costs and frame relay virtual circuit, and constant information rate components provide the service level assurance that corporations need for business-critical IP and frame applications.
Filling the Broadband Access GapBy incorporating multilink frame relay, inverse multiplexing over ATM (IMA) and/or multilink point-to-point protocol (MLPPP), new access equipment from the likes of Advanced Switching Communications Inc. and Tiara Networks Inc. offers the ability to "bond" multiple 1.5mbps T1s into a single broadband pipe. Benefits for Service Providers and Customers: | |
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| Source: Advanced Switching Communications Inc. (www.asc.com) | |
For the longer term, Intermedia also is "testing all the advanced packet telephony and IP quality of service technologies now emerging, and we think they're beginning to solve the challenge of replicating public switched telephone network quality," Binford adds. "You'll see an evolution in our core network to offer advanced voice over integrated packet networks."
PoP Reach
The next bandwidth demand sweet spot among small and medium-sized businesses and branch offices will be 3mbps to 6mbps, the equivalent of two to three T1 links, says Jim DesRossier, director of business development for Paradyne Networks. Much of that bump in demand upward from T1 service, according to DesRossier and others, is being driven by the increasing need for Internet access.
Because Tiara Networks has developed a family of frame boxes of varying sizes--some of which can aggregate four or eight frame circuits, and others can aggregate thousands of circuits--PSINet plans to spread the equipment geographically, "to move access closer to our customers at distributed points of presence," says Mark Fedor, vice president of engineering for PSINet, one of the oldest and largest Tier 1 Internet backbone providers. "The new Tiara products fit perfectly with our strategy to provision IP services over our high-performance, multiservice frame relay backbone."
For PSINet, the Aggregated Virtual Circuit services afforded by MFR will translate to enhanced bandwidth options in its Multi-Megabit Service, filling the gap between T1 and T3 with bundling of up to seven T1 lines. "The service is ideal for customers with high bandwidth requirements, such as high traffic web servers, application servers and multimedia servers that require more than T1 Internet access," the company says.
In addition to using MFR to bond access lines at the frame relay link layer, the Tiara gear also can bond access at the services layer, employing a similar bonding protocol, multilink point-to-point protocol (MLPPP). With MLPPP, Tiara's Multi-Megabit Access Concentrator CPE is able to separate WAN aggregation functions from the customer's router, enabling the router to offload that aggregation job to the concentrator. Tiara's IP multiplexing uses MLPPP to bond up to eight T1s from the customer premises.
Now armed with both MLPPP and MFR, Tiara's CPE box passes a single customer's aggregated traffic out into PoPs that can be tiered in size, ranging from a small PoP aggregating 128 customers, to medium-sized and large PoPs aggregating thousands of customers. At the small PoP level, the Series 7000 aggregator is also a bona fide frame relay switch, which can backhaul traffic to a main PoP via T3 fiber optic links.
This ability to extend NxT1 access farther and farther from its core frame switches in an affordable fashion is what drew PSINet to the Tiara Networks equipment, says Kash Mitra, vice president of marketing for Tiara. PSINet now can offer fractional T1, T1 and NxT1 services to more and smaller users at lower cost.
"We replace proprietary multiplexers, which require boxes at both the PoP and customer premise, and which require a channel bank and high-cost serial ports," Mitra says. "Now you can get rid of all that, saving up to $150,000 for every seven customers of four T1s each. Plus, you gain PoP space and power consumption." Typically, he adds, upfront PoP costs can shrink from $180,000 to the $20,000 to $25,000 range.
In addition to developing a distributed MFR and MLPPP aggregation architecture, Mitra says, carriers like PSINet can contemplate distributing the aggregation function all the way to the multitenant unit (MTU) building. To do this, Tiara offers the Series 6200 aggregator, designed to bond up to four T1s in a commercial building, campus or hotel. It's "a low-cost alternative to expensive ATM T3 access," he says. To extend network reach to sites that lie even beyond copper loop reach, the system also is designed to accommodate wireless broadband WAN transmission. In development now, the Tiara Series 1450 aggregator will add common frame relay protocols such as IPX.
Tiara eschews ATM and IMA, arguing that it is capacity inefficient. Where ATM forces a single 64-byte packet to take up two 56-byte ATM cells, "losing more than one T1 out of four," Mitra says, "with MFR or MLPPP, you're losing no more than 3 percent in overhead."
Whether for Internet access, packet voice or other applications, MFR stands to strengthen the hand of frame relay among businesses that need more than 1.5mbps access but cannot afford 45mbps access.
"Frame relay growth is phenomenal because it has incorporated most of the quality control and traffic engineering promise of ATM, without the complexity and cost," says DesRossier. Paradyne is rolling out not only MFR access boxes but also equipment capable of monitoring and assuring SLAs at the fractional T1, T1 and NxT1 levels.
"As new applications continue to grow the pipe, MFR accommodates them while maintaining frame relay's cost and simplicity edge," DesRossier says. "We do not see MFR as a short-term stopgap. It is a growth technology for the foreseeable years."
