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mode LSRs (ATM LSRs). MPLS CoS functions map nearly one-for-one to IP CoS functions on all
interface types.
Label Switch Controller
The Label Switch Controller (LSC) with Cisco s BPX 8620 wide area switch and BPX 8650 IP+ATM
switch delivers scalable integration of IP services over an ATM network.
The LSC enables the BPX 8620 and 8650 to:
" Participate in a MPLS network
" Directly peer with IP edge routers
" Support the full suite of IP features available in Cisco IOS
The Label Switch Controller (LSC) is a label switch router (LSR) that controls the operation of a
separate ATM switch. Together, the router and ATM switch function as a single ATM MPLS router
(ATM-LSR). A Cisco 7200 or 7500 series router acts as the LSC, and a Cisco BPX 8600 Service Node
or a partner s switch acts as the VSI-controlled ATM switch. The LSC controls the ATM switch using
the Cisco Virtual Switch Interface (VSI), which runs over an ATM link connecting the two.
Cisco IOS Switching Services Configuration Guide
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Multiprotocol Label Switching Overview
Label Switch Controller
MPLS s highly scalable IP+ATM integration is created by the LSC using a direct peer relationship
between the BPX 8620 or 8650 and IP edge routers. This removes the limit placed on the number of IP
edge routers, seen in traditional IP-over-ATM networks, allowing service providers to keep pace with
the growing demand for IP services. The LSC also supports the easy, quick, and direct implementation
of advanced IP services over ATM networks with BPX 8620s and 8650s.
The combination of a LSC and the ATM switch it controls is shown in Figure 20.
Figure 20 Label Switch Controller and Controlled ATM Switch
Other label controlled
Label switch controller
or nonlabeled controlled
router interfaces
Master control port/
VSI
switch control port
Controlled ATM switch LC-ATM interface
LC-ATM LC-ATM
interface interface
In Figure 20, the dotted line represents the external interface of the LSC and controlled switch as seen
in the IP routing topology. The controlled ATM switch shows one or more TC-ATM interfaces at this
external interface and the LSC itself may have additional interfaces that may or may not be label
controlled.
Cisco IOS Switching Services Configuration Guide
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