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Figure 8
Frame Relay Architecture
Many service providers offer IP Internet access and VPN products over existing Frame Relay access networks. Frame
Relay packet switched networks allow flexibility to build in contention and to better dimension infrastructure
resources based on traffic profiles, allowing better economies of scale. When aggregating Frame Relay circuits, the
Cisco 10000 Series is usually located in a central POP and connects to local switch nodes through copper or optical
interfaces. Typically, these connections are effected with nonchannelized interfaces. Frame Relay data-link
connection identifiers (DLCIs) are terminated on the Cisco 10000 Series with customer IP traffic routed through the
core network. Frame Relay encapsulation is supported on the full range of packet interfaces, including channelized
and nonchannelized modules. Numerous Frame Relay options and services are supported on the platform, including
traffic shaping and QoS.
ATM Aggregation
ATM is prevalent in many incumbent local exchange carrier (ILEC) and PTT access networks, and many providers
use the technology as the foundation for multiservice platforms. Over the past several years, ATM has been used to
provide transport services for many applications, including backhaul for DSL services and leased-line emulation for
Internet and VPN services.
Figure 9
ATM Architecture
When used as an ATM aggregator, the Cisco 10000 Series is usually placed in a central POP and connected to a local
ATM switching node through optical interfaces. ATM virtual circuits are terminated on the device, and customer IP
traffic destined for the Internet or VPN is routed onto the core network.
IP
Clear Channel
Interface
IP
Frame Relay
Frame Relay/DLC1
SONET/SDH
Cisco
10000
Series
IP Network
T1/E1
Business
Customer
IP
ATM
Interface
IP
ATM
RFC 1483
SONET/SDH
Cisco
10000
Series
IP Network
T1/E1
Business
Customer