Specifications

Installation and Operation Manual Chapter 1 Introduction
MPW-1 MP-4100 Ver. 2.0 Functional Description 1-17
PSN Configuration Parameters
MPW-1 enables the user to select the PSN type (UDP/IP or MPLS/ETH), and
configure the PSN transport parameters.
The PSN parameters, which are reflected in the pseudowire header structure,
enable specifying the requested priority or quality of service for pseudowire
traffic generated by the MPW-1. The applicable parameters depend on PSN type:
• When the PSN is based on Layer 2 forwarding, the user can specify the VLAN
priority (per IEEE 802.1p) for the Ethernet frames carrying pseudowire
packets. The priority is always selectable for traffic forwarded through the
Megaplex-4100 GbE ports, because for these ports VLAN tagging is always
enabled; when using other bridge ports as pseudowire exit ports, it is
necessary to enable VLAN tagging in order to request a specific priority.
• When the PSN uses IP routing, the user can specify the Type of Service (ToS)
per RFC791; if the PSN supports RFC2474, ToS is interpreted as a DiffServ
codepoint per RFC2474.
• When the PSN uses MPLS, the user can specify the EXP bits. In addition, the
user can also add ingress and egress tunnel labels, which enable network
operators to plan preferential forwarding of pseudowire traffic using the
specified tunnel labels.
Another parameter that may be used, for compatibility with older TDMoIP
implementations, is the packet payload version, V1 or V2.
Ethernet Subsystem
The MPW-1 Ethernet subsystem, included in the functional block diagram shown
in
Figure 1-6 , includes:
• External Ethernet ports
• Layer 2 Ethernet switching subsystem
• Internal Fast Ethernet data ports, used only when CL.1/GbE or CL.1/155GbE
modules are installed in the chassis: each port connects to the Ethernet
traffic handling subsystem of one CL module
When neither CL.1/GbE, nor CL.1/155GbE modules, are installed in the
Megaplex-4100 chassis, the internal Fast Ethernet ports are not used: in this
case, pseudowires can be directed only to the external Ethernet ports of this
MPW-1.
• Internal Fast Ethernet management ports, connected to the Megaplex-4100
management subsystem on the CL modules. These ports are always active
• Ethernet termination and processing: provides the interface between the
Layer 2 Ethernet switching subsystem and the local TDM cross-connect matrix
External Ethernet Ports
The external Ethernet ports have 10/100 Mbps interfaces capable of
auto-negotiation. The user can configure the advertised data rate (10 or
100 Mbps) and operating mode (half-duplex or full-duplex). Alternatively,
Note