Cisco PWR-400W-AC= データシート
Data Sheet
© 2008 Cisco Systems, Inc. All rights reserved. This document is Cisco Public Information.
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Layer 2 VPNs can be delivered over a pure Layer 2 infrastructure. By enabling features as 802.1Q
tunneling, Layer 2 Protocol Tunneling (L2PT), and VLAN translation, the Cisco ME 6524 allows the
customer to segment and transparently transport the users’ traffic.
Alternatively, Layer 2 VPNs can be offered through Ethernet over MPLS. This technology provides
a Layer 2 tunneling mechanism over a Layer 3 MPLS network, thus using the Layer 3 network
convergence protocols without the need for Spanning Tree Protocol.
Layer 3 VPNs, often referred to as MPLS VPNs, are multipoint Layer 3 services (see Figure 3).
The PFC3C complex on the Cisco ME 6524 enables MPLS in hardware and provides QoS and
resiliency capabilities such as MPLS Experimental (MPLS EXP) bit marking, MPLS Traffic
Engineering (MPLS TE), and MPLS Fast Reroute (MPLS FRR).
Figure 3. Cisco ME 6524 Supports Layer 2 and Layer 3 VPNs
Key Features and Benefits
Table 1 describes the features and benefits of the Cisco ME 6524, and Table 2 provides
information about its scalability.
Table 1.
Cisco ME 6524 Features and Benefits
Features
Benefits
Layer 2 Switching
IEEE 802.1Q
802.1Q Tunneling
Layer 2 Protocol Tunneling (L2PT)
VLAN Translation
802.1Q and L2PT are the service enablers to offer Layer 2 VPNs. By
encapsulating users' data frames in an outer 802.1Q tag and by
tunneling users' PDUs, 802.1Q tunneling allows to segregate users'
traffic and to scale the number of users beyond the 4096 VLAN
boundary
encapsulating users' data frames in an outer 802.1Q tag and by
tunneling users' PDUs, 802.1Q tunneling allows to segregate users'
traffic and to scale the number of users beyond the 4096 VLAN
boundary
IEEE 802.1D
IEEE 802.1w
IEEE 802.1s
Flexlink
Port Aggregation Protocol (PAgP)
IEEE 802.3ad
Unidirectional Link Detection
Protocols such as IEEE 802.1D, IEEE 802.1w, and IEEE 802.1s help
ensure business continuity by minimizing the network convergence
time for time-sensitive applications.
ensure business continuity by minimizing the network convergence
time for time-sensitive applications.
Flexlink provides fast failover over point-to-point connections, without
the overhead of control protocols.
the overhead of control protocols.
PAgP and IEEE 802.3ad increase bandwidth availability and provide
fast link failover within the Cisco EtherChannel bundle.
fast link failover within the Cisco EtherChannel bundle.
Unidirectional Link Detection (UDLD) increases the network reliability
by quickly detecting unidirectional links or misplaced fiber connectors.
by quickly detecting unidirectional links or misplaced fiber connectors.