Specifications

Installation and Operation Manual Chapter 1 Introduction
MPW-1 MP-4100 Ver. 2.0 Functional Description 1-21
 Pseudowires configured on different MPW-1 modules must be configured
with different peers, even if the destination address is the same.
 Different peers must not have the same destination IP address and the
same next hop IP address (at least one of these parameters must be
different). Therefore, if it necessary for several pseudowires to reach the
same IP address, create separate router interfaces.
• Static routes: to control the paths used to reach the pseudowire
destinations, the Megaplex-4100 router function supports the definition of
up to 100 static routes, in addition to a default gateway. To ensure that only
valid forwarding information is used, the user can configure the ARP aging
time.
Within the Megaplex-4100, pseudowires are forwarded to the appropriate exit
port (always a router interface) by internal E-line Ethernet flows (an E-line flow is
a type of Ethernet logical connection that interconnects two bridge ports).
Megaplex-4100 supports traffic and management flows. MPW-1 bridge ports can
also serve the management flow. Unless specifically mentioned otherwise, in this
manual the term flow means traffic flow.
Each router interface serves as a bridge port for the pseudowires using it (in
addition, each MPW-1 Ethernet port also serves as a bridge port).
Bridge ports which are router interfaces appear in automatically created Ethernet
flows. Actually, defining a router interface automatically creates the Ethernet
E-line flow needed to internally route the pseudowire from the MPW-1 module to
the best suited router interface, considering the specified pseudowire peer.
To help you design the routing information, the following list summarizes the
process used to select the router interface to be used for each pseudowire peer:
1. If the peer IP address is in the subnet of a router interface, that interface will
always be used.
2. If the peer IP address is not within a router interface subnet, then the router
checks if the specified peer next hop address is within the subnet of a router
interface. If such a router interface is found, it is selected to serve as the
pseudowire exit port.
3. If neither of the previous conditions are fulfilled, the router checks if the
specified peer next hop address is specified in a static route that is within the
subnet of a router interface.
4. The last priority is to use the router interface that is within the default
gateway subnet.
Redundancy
The MPW-1 modules support dual-cable redundancy with parallel transmission
(you can find additional details on redundancy schemes supported by
Megaplex-4100 in the
Megaplex-4100 Installation and Operation Manual ). Since
traffic is always connected through internal DS1 ports, the redundancy protection
is configured on these ports.
Several redundancy protection topologies can be used, as described below.
Note