CHAPTER 4
Configuring Multicast Offload on the Satellite nV
System
This chapter describes the configuration of the Satellite Network Virtualization (Satellite nV) multicast
offload on the Cisco ASR 9000 Series Aggregation Services Routers.
•
Need for Multicast Offload, page 103
•
Scope and Prerequisites, page 104
•
Multicast Offload Terminology, page 106
•
Overview of Multicast Offload, page 106
•
Restrictions for Multicast Offload, page 110
•
Configuring Satellite nV Multicast Offload, page 111
Need for Multicast Offload
The Satellite nV System architecture currently requires the Cisco ASR 9000 Series Router host to process all
replications for supported multicast traffic and topology profiles. This is in line with the envisioned port
extender functionality of the satellite devices where all protocol processing and forwarding decisions happen
on the host to fully utilize the IOS-XR functionalities. With the introduction of support for a wider variety of
satellite topologies, the satellites are no longer restricted by a need for direct connection to the hosts. The
satellites can be chained to a Dual Host system to form a Ring topology or can be reached over an Layer-2
fabric connection through transport provider EVCs.
Refer the Configuring the Satellite Network Virtualization (nV) System chapter for more information on
Simple Ring and Layer 2 fabric topologies.
Note
This use of satellite fabric connections over EVCs or sharing of the same fabric link by a chain of satellite
devices has introduced new bandwidth conservation requirements. One such specific case is the forwarding
of multicast traffic over satellite ports where the Host currently does all the replication even if all the copies
are destined to the ports on the same satellite device. The satellite device is unaware of any multicast group
or membership and if multiple receivers are present on the ports of the same satellite, multiple copies of the
Cisco ASR 9000 Series Aggregation Services Router nV System Configuration Guide, Release 5.3.x
103