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Updated:April 17, 2005
The Cisco® I-Flex approach combines shared port adapters (SPA) and SPA interface processors (SIP), providing an extensible design that enables service prioritization for data, voice, and video services. Enterprise and service provider customers can take advantage of improved slot economics resulting from modular port adapters that are interchangeable across Cisco routing platforms. The I-Flex design maximizes connectivity options and offers superior service intelligence through programmable interface processors that deliver line-rate performance. I-Flex enhances speed-to-service revenue and provides a rich set of quality of service (QoS) features for premium service delivery while effectively reducing the overall cost of ownership. This data sheet contains the specifications for the Cisco 2-Port and 4-Port OC-3c/STM-1c ATM Shared Port Adapters (SPAs), and the Cisco 1-Port OC-12c/STM-4c ATM SPA (refer to Figure 1).
Figure 1. Cisco 2-Port and 4-Port OC-3 ATM SPAs and Cisco 1-Port OC-12 ATM SPA
This data sheet details the features of the new modular ATM SPAs for Cisco 7600 Series Routers and Catalyst 6500 Series Switches. The Cisco ATM SPAs, in conjunction with other SPAs implementing various types of network technologies, allow the user to flexibly build cost-effective routing solutions focusing on point-of-presence (POP) edge, customer premises equipment (CPE), and enterprise applications.
Designed for all telcos and Internet service providers (ISPs), the Cisco ATM SPAs support a variety of port choices and granularity, including OC-3c/STM-1c and OC-12c/STM-4c interfaces for worldwide use. These modules are designed to support the convergence of data, voice, and video services, allowing customers to migrate existing voice and video traffic onto a corporate data network for substantial cost savings. The Cisco ATM SPAs include a comprehensive ATM feature set including per-virtual-circuit and per-virtual-path traffic shaping, ATM service classes including constant bit rate (CBR), variable bit rate non-real time (VBR-nrt), variable bit rate real time (VBR-rt), unspecified bit rate (UBR and UBR+), Multiprotocol Label Switching (MPLS), QoS, a high-performance segmentation-and-reassembly (SAR) architecture, and support for a large number of ATM virtual connections. All these features are based on industry specifications and standards. In conjunction with the SIPs, the Cisco ATM SPAs continue to deliver new features made possible by industry-leading Cisco IOS® Software protocols, services, and an ATM-rich feature set.
The Cisco ATM SPAs address the growing demand for improved ATM QoS features, which are combined with the advanced Layer 3 class-of-service (CoS) capabilities provided by various Cisco routers. Robust QoS mechanisms help prioritize traffic from traditional and high-speed LANs over an ATM network. Network managers can now cost-effectively terminate high-speed ATM, enabling rich QoS features for aggregation or campus applications.
The Cisco ATM SPAs can be inserted in the Cisco SIPs that support various edge services such as:
• IPv4, IPv6, and MPLS hardware-assisted forwarding
• Enhanced security features such as extended access control lists (ACLs), Unicast Return Path Forwarding (URPF), Internet Control Message Protocol (ICMP) rate limiting, and others
• Extensive QoS implementation based on either "classical" QoS (three type-of-service [ToS] bits), Differentiated Services (DiffServ [six DiffServe code point (DSCP) bits]), or MPLS (3 bits EXP)
• Enhanced NetFlow, statistics, and billing data to allow service providers to generate different billing profiles for their customers
• MPLS-VPN support that allows for Layer 3 VPN deployments and various related applications
• Any Transport over MPLS (AtoM) or pseudowire edge-to-edge emulation 3 (PWE3) support for transport solutions
The Cisco ATM SPAs use replaceable Small Form-Factor Pluggable (SFP) optical modules that allow customers the flexibility to use different optical interfaces on the same SPA.
The Cisco ATM SPAs are hot-swappable and support service-transparent online insertion and removal (OIR), allowing removal of the SPA without impacting the interface processor and other SPAs.
The Cisco ATM SPAs are designed for a wide range of network applications. The specific combination of ATM features and standards makes the Cisco ATM SPAs ideal for both enterprise-based ATM WANs and service provider infrastructures.
Enterprise-Based ATM WAN
ATM technology is now a favored choice for very high-bandwidth corporate connectivity across an enterprise WAN. Providing connectivity to geographically dispersed facilities, typical ATM WAN interfaces range from 34 to 622 Mbps. These very large WAN "pipes" supply ample bandwidth for the needs of corporate infrastructures today, with room for growth in the future. Enterprise-based ATM WANs can be deployed through private networks or through a public ATM service from large service providers.
With the many advanced ATM capabilities and support for MPLS and QoS (such as per-virtual circuit and per-virtual path traffic shaping), the Cisco ATM SPAs are ideal for interconnecting Cisco 6500/7600s at central sites or larger remote sites through an enterprise-based ATM WAN. Through OC-3c/STM-1c or OC-12c/STM-4c ATM links, the Cisco ATM SPAs can be connected to any standards-based ATM WAN switch, including the Cisco LightStream
® 1010, Cisco Catalyst
® 8500 Series, Cisco MGX® 8800 Series, Cisco BPX® 8600, and Cisco IGX 8400 Series at the switching core.
In the campus backbone or metropolitan-area network (MAN), the OC-12c/STM-4c provides the same scaled-up ATM bandwidth as in the POP when the bandwidth between the ATM switches is increased.
The Cisco ATM SPAs allow you to combine a diverse range of LAN technologies, including Fast Ethernet and Gigabit Ethernet, with ATM in enterprise deployments.
Service Provider Infrastructures
ATM deployment in service provider infrastructures has seen tremendous growth in recent years as well. This growth has been spurred for several reasons:
• ATM provides highly scalable bandwidth within SONET/SDH infrastructures.
• ATM is inherently a multiservice (data, voice, and video) technology.
• ATM is based on international standards.
The Cisco ATM SPAs provide high-performance interconnectivity for service provider intra-POP applications needing IP transport. Cisco ATM SPAs can also be used for ATM aggregation of remotes sites at the edge of the service provider networks.
Because they support ATM Forum specifications and IETF and ITU standards, the Cisco ATM SPAs can be deployed with any standards-based ATM switch, including the Cisco MGX 8800 Series, Cisco BPX 8600 Series, Cisco IGX 8400 Series, Cisco LightStream 1010, and Cisco Catalyst 8500 Series products.
The Cisco ATM SPAs in conjunction with the Cisco SIPs allow service providers to effectively manage the bandwidth at the edges of the network while implementing value-added Layer 3 services. With advanced traffic-shaping features and support for many ATM service classes, the Cisco ATM SPAs can be widely deployed in many parts of the service provider backbone. Advanced traffic-management features (such as per-virtual-circuit and per-virtual-path traffic shaping) are required to prevent traffic from one customer impacting traffic of another.
Layer 2 Transport Services
In order to cost-effectively deliver new revenue-generating connectivity options to their customer base, traditional ATM and Frame Relay service providers (telcos, regional Bell operating companies [RBOCs], and incumbent local exchange carriers [ILECs]) are migrating services from cell-based ATM transport networks to packet-based MPLS/IP networks. This migration allows them to deliver the rich functionality of services associated with Layer 3 while gaining the ability to account for, prioritize, and effectively offer these services for profit.
Using the Cisco ATM SPAs in conjunction with the Cisco SIPs, by tunneling core ATM trunks through an MPLS/IP network, you can take advantage of your existing investment in IP networks - networks that are currently low-revenue-generating - and, in essence, enable those networks to mimic and build upon the class-of-service (CoS) abilities of current Frame Relay- and ATM-based networks, all while maintaining continuity of Layer 2 services.
Features and Benefits
The ATM SPAs offer many advantages, including support for the following features:
• Per-virtual-circuit and per-virtual-path traffic shaping: Traffic shaping is a function typically provided on ATM edge devices to ensure that bursty traffic conforms to a predetermined "contract." To implement traffic shaping, the Cisco ATM SPAs support per-virtual-circuit and per-virtual-path shaping, including industry-leading minimum 1-kbps granularity, allowing flexibility and control over every virtual circuit and virtual path configured.
• IP QoS and Layer 3 QoS features: The Cisco SIPs and ATM SPAs support per-virtual-circuit IP QoS features that allow you to apply advanced-queuing and bandwidth-management functions, including Low Latency Queuing (LLQ), to individual virtual circuits to avoid congestion and delay. In addition, extended ACLs and committed access rate (CAR) are supported on a per-virtual-circuit basis on both ingress and egress.
• IP/MPLS-to-ATM QoS mapping: Also supported is IP-to-ATM QoS setting through cell-loss priority (CLP) bit support and virtual circuit bundling, which allows you to divide traffic on different virtual circuits, depending on the desired CoS.
• Any Transport over MPLS (AToM): MPLS is the primary technology for ATM/IP convergence, and all the Cisco ATM SPAs allow the transport of Layer 2 traffic across an MPLS network. AToM allows a migration path toward the consolidation of IP and ATM networks while protecting existing equipment investment, and it accommodates the scaling of existing services using MPLS. All ATM operation, administration, and maintenance (OAM) functions are transported.
• Link fragmentation and interleaving (LFI): LFI uses the built-in fragmentation capabilities of Multilink Point-to-Point Protocol (MLPPP) to reduce delay and jitter (variations in delay) caused by variable-sized large packets being queued in between relatively small packets. With LFI, packets larger than a configured fragment size are fragmented and encapsulated in an MLPPP header.
The Cisco SPA/SIP portfolio offers these additional advantages:
– Superior flexibility, supporting a combination of interface types on the same interface processor for consistent services, independent of access technology.
– Pioneering programmable interface processors that provide flexibility for the service diversity required in next-generation networks.
– Innovative design that supports intelligent service delivery without compromising on performance.
• Increased speed to service revenue
– The scalable, programmable Cisco architecture extended to 10 Gbps dramatically improves customer density, increasing potential revenue per platform.
– Interface breadth (copper, channelized, POS, ATM, and Ethernet) on a modular interface processor allows service providers to roll out new services more quickly, helping ensure that all customers large and small receive consistent, secure, and guaranteed services.
– High-density SFP interfaces are featured for high-port-count applications with reach flexibility. Future optical technology improvements can be adopted using existing SPAs.
• Dramatically improved return on your routing investment
– Improved slot economics and increased density reduce capital expenditures (CapEx).
– The ability to easily add new interfaces as they are needed enables a "pay-as-you-grow" business model while still offering a high-density solution.
– SPAs are shared across multiple platforms, and can be easily moved from one to another, providing consistent feature support, accelerated product delivery, and a significant reduction in operating expenses (OpEx) through common sparing as service needs change.
Table 1 gives product specifications and Table 2 lists optical specifications of the Cisco ATM SPAs.
Table 1. Product Specifications
Cisco Catalyst 6500 Series Switches
Cisco 7600 Series Routers
Port Density per SPA
• OC-3/STM-1 ATM SPA: 2-port and 4-port
• OC-12/STM-4 ATM SPA: 1-port
SFP optics module (refer to optical parameters in Table 2)
• IETF RFC 2684 (updated RFC 1483) support for multiple protocol encapsulations over ATM
• IETF RFC 2364 and 2516 for Point-to-Point Protocol (PPP) over ATM
• IETF RFC 1577 support for classical IP and Address Resolution Protocol (ARP) over ATM
• ATM Forum User-Network Interface (UNI) 3.0, 3.1, and 4.0
Features and Functions
• UBR and UBR+
• Maximum virtual circuits: 16,000 (subject to overall configuration limitations)
• ATM and IP CoS
• Per-virtual circuit and per-virtual path traffic shaping
• Per-virtual circuit and per-virtual path statistics
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For More Information
For more information about the Cisco SPA/SIP portfolio, visit
http://www.cisco.com/go/spa or contact your local Cisco account representative.