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DES-3810 Series Layer 3 Managed Ethernet Switch Web UI Reference Guide
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Pseudo-Wire (PW) and AC based on local information. A PW is an emulated point-to-point connection over a packet
switched network that allows the interconnection of two nodes with any Layer 2 technology.
The required functions of PWs include encapsulating service-specific bit streams, cells, or PDUs arriving at an ingress
port and carrying them across an IP path or MPLS tunnel. PWs provide the following functions in order to emulate the
behavior and characteristics of the native service.
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Encapsulation of service-specific PDUs or circuit data arriving at the PE-bound port (logical or physical).
•
Carriage of the encapsulated data across a PSN tunnel.
•
Establishment of the PW, including the exchange and/or distribution of the PW identifiers used by the PSN
tunnel endpoints.
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Managing the signaling, timing, order, or other aspects of the service at the boundaries of the PW. Service-
specific status and alarm management.
One or more PWs are carried in an MPLS tunnel from one PE to another. Any given frame travels first on its ingress
AC, then on a PW, and then on its egress AC. This particular combination forms a virtual circuit between two CE
devices.
Virtual Private Network (VPN)
- A VPN is the extension of a private network that encompasses links across public
networks like the Internet. A VPN enables you to send data between two computers across a public network in a
manner that emulates the properties of a point-to-point private link.
Virtual Private Wire Service (VPWS)
- A VPWS is a VPN service that provides Layer 2 point-to-point virtual circuit
connectivity between customer sites over a provider network.
Packet Switched Network (PSN)
- The PSN is the network through which the tunnels supporting the VPN services
are set up. On this Switch, the PSN is a MPLS network.
Customer Edge Device (CE)
- The CE resides on a customer network and has one or more interfaces directly
connected to provider networks.
Provider Edge (PE)
- The PE resides on a service provider network and connects one or more CEs to the network.
Provider Router (PR)
- The PR resides on a service provider network and provides fast packet switching.
Attachment Circuit (AC)
– The AC is the physical or virtual circuit attaching a CE to a PE. The Ethernet port, VLAN
or (port, VLAN) pair can be used to identify the AC.
Pseudo-Wire (PW)
– The PW is a mechanism that carries the essential elements of an emulated circuit from one PE
to another PE over a PSN. The PW-ID and PW-type are used to identify a Pseudo-Wire. The PW-ID is a non-zero, 32-
bit, connection ID. The PW-ID and PW-type must be the same at both endpoints.
Tunnel Label
- The Tunnel Label is used to allow encapsulated Ethernet packets to cross the MPLS network through
the tunnel LSP.
VC Label
– The VC Label is used as a de-multiplexer field so that multiple PWs can be carried in a single tunnel. A
particular VC Label value must be agreed upon by the ingress and egress PEs, either by using LDP signaling or by
using a static configuration. The VC Label must be at the bottom label of an MPLS label stack. The EXP field in the
VC Label can be used to carry QoS information. The ingress PE must configure the TTL value of the VC Label to 2.
VPWS Settings
This window is used to configure the VPWS settings.
To view this window, click
VPN > VPWS > VPWS Settings
as shown below:
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