Specifications

Installation and Operation Manual Chapter 1 Introduction
MPW-1 MP-4100 Ver. 2.0 Overview 1-5
(CCS) such as Signaling Scheme 7 (SS7), ISDN PRI signaling, etc.) can be
transparently transferred within the pseudowire, as regular data timeslots.
• Fractional E1 and T1 services, with or without CAS, are supported by means
of TDMoPSN. Without CAS, CESoPSN can also be used.
• HDLC traffic can be carried over framed and unframed E1 and T1 using
HDLCoPSN. This enables efficient and transparent transfer of Frame Relay
traffic.
Packet structure is independently selectable for each pseudowire, for
compatibility with the various pseudowire protocols (TDMoPSN, CESoPSN,
HDLCoPSN, SAToPSN) and the PSN type (UDP/IP or MPLS/ETH). For maximum
flexibility in system applications, the framing format of the pseudowire device at
the destination (referred to as a
pseudowire peer ) can also be taken into
account, thus in many cases traffic using the E1 standards can be directed at
destinations using the T1 standards, and vice versa.
The pseudowire exit port toward the PSN is also selectable: either via one of the
MPW-1 Ethernet ports, or, when Megaplex-4100 is equipped with GbE ports, via
any other bridge port (GbE, Fast Ethernet, or VCG) of any module installed in the
chassis. The selectable exit ports are configured as router interfaces, where each
router interface has its own IP source address, and optionally – its own VLAN
(each MPW-1 module supports up 6 interfaces, for a maximum of 100 router
interfaces per Megaplex-4100). The user can also specify static routes to control
the IP routing.
The internal MPW-1 Ethernet subsystem is based on an Ethernet switch with
built-in flow classification engine, and support for VLAN tagging according to IEEE
802.1Q and 802.1p. The Ethernet switch switches traffic among the module
Ethernet ports and the pseudowire engine, and, when a CL module with GbE
ports is installed in the Megaplex-4100 – also to the Ethernet traffic subsystem
of the CL module (for connection via any other bridge port in the Megaplex-4100,
via the CL GbE ports to a packet-switched network, or for transmission through
the SDH/SONET network via virtually concatenated groups). The internal Ethernet
switch also enables connecting MPW-1 Ethernet ports to the Megaplex-4100
management flow.
MPW-1 supports the OAM mechanism for connectivity verification, and
pseudowire configuration mismatch prevention. MPW-1 also supports a wide
range of performance monitoring statistics to enable analyzing transmission
problems and optimizing PSN transmission performance.
To enable optimal handling of pseudowire traffic within the PSN, the following
parameters can be configured:
• For Ethernet transport networks: outgoing pseudowire packets are assigned
to a dedicated VLAN ID according to 802.1Q and marked for priority using
802.1p bits.
• For IP transport networks: outgoing pseudowire packets are marked for
priority using DSCP, ToS, or Diffserv bits. This allows TDMoIP packets to be
given the highest priority in IP networks.
• For MPLS transport networks: outgoing pseudowire packets are assigned to a
specific MPLS tunnel, and marked for priority using the EXP bits.