Panasonic NN46240-501 - Manual (Page 40)

1 Product overview
Nortel Secure Router 8000 Series
Configuration Guide - Basic Configuration
• varying routing policies and sharing of routes discovered by both static and dynamic
routing protocols
In networking practice, the routing table is always large, while the memory of the router is
limited. To resolve this issue, the Secure Router 8000 Series provides a size control
mechanism for routing tables. It monitors the current free memory of the system, based on
which it decides whether to add routes to the routing table and whether to keep the connection
of the routing protocol. In addition, the Secure Router 8000 Series supports load sharing and
route backup functions.
1.3.9 Multicast routing protocols
This section describes the multicast routing protocols supported by the Secure Router 8000
Series.
Internet Group Management Protocol
The Secure Router 8000 Series supports the Internet Group Management Protocol (IGMP)
that is used to establish and maintain multicast members between the IP host and the directly
connected multicast routers.
Multicast routing protocol support
The Secure Router 8000 Series supports multicast routing protocols as follows:
• Protocol Independent Multicast-Dense Mode (PIM-DM) and Protocol Independent
Multicast-Sparse Mode (PIM-SM) (used in the same area)
• Multicast Source Discovery Protocol (MSDP) and Multiprotocol Border Gateway
Protocol (MBGP) (used between areas)
1.3.10 MPLS features
Multiprotocol Label Switching (MPLS) uses short labels with a fixed length to encapsulate
network layer packets. MPLS performs the following functions:
• acts as an intermediate layer between the network and link layers
• provides connection-oriented network services through the services obtained from link
layer protocols such as PPP and FR
The Secure Router 8000 Series forms forwarding equivalence classes (FECs) based on
information such as the IP address prefix, and performs the following roles:
• generates the label-forwarding table
• forwards traffic information of di^erent FECs (with different label fields in the headers)
through the different label switch paths (LSPs)
MPLS supports the following:
• policy- and constraint-based routing (such as limitations based on the VPN and Diff-Serv)
on LSPs, which enables you to select a router from the MPLS network to establish an
LSP
• LSP tunneling technology with a label stack at both the ingress and egress of a tunnel to
perform tunnel nesting and to meet different application requirements
The Secure Router 8000 Series provides the following MPLS functions:
1-14 Nortel Networks Inc. Issue 5.3 (15 January 2009)