Specifications

Table Of Contents
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Release Notes for Cisco 7000 Family for Cisco IOS Release 12.1 T
78-10811-05
New and Changed Information
Frame Relay Fragmentation with Hardware Compression
Platforms: Cisco 7200 series routers
The Frame Relay Fragmentation with Hardware Compression feature introduces the following functionality:
Frame Relay Fragmentation and Hardware Compression Interoperability
This new feature enables FRF.12, FRF.11 Annex C, and Cisco proprietary fragmentation to work with
hardware compression on interfaces and virtual circuits (VCs) using Cisco proprietary or Internet
Engineering Task Force (IETF) encapsulation types.
Hardware Compression and Header Compression Interoperability
The Frame Relay Fragmentation with Hardware Compression feature introduces a new, proprietary
hardware and software compression protocol called data-stream compression, which can be used on the
same VC or interface as header compression. Data-stream compression is functionally equivalent to
FRF.9 compression and must be used with Cisco proprietary encapsulation. Frame Relay fragmentation
can also be enabled.
Hardware Compression and Software Compression Interoperability
The Frame Relay Fragmentation with Hardware Compression feature provides hardware and software
compression interoperability when hardware compression is configured on one side of the link and software
compression is configured on the other side.
Frame Relay Switching Diagnostics and Troubleshooting
Platforms: Cisco 7200 series routers
The Frame Relay Switching Diagnostics and Troubleshooting feature enhances Frame Relay switching
functionality by providing tools to diagnose problems in switched Frame Relay networks. The show
frame-relay pvc command has been enhanced to display detailed reasons why packets were dropped from
switched PVCs. The command will also display the local status, the Network-to-Network (NNI) status, and
the overall status of NNI PVCs. If a network problem is observed, the new debug frame-relay switching
command can be used to display the status of packets on switched PVCs at regular intervals. This new debug
command displays information such as the number of packets that were switched, why packets were
dropped, and changes in status of physical links and PVCs.
IGMP, Version 3
Platforms: Cisco 7100 series routers, Cisco 7200 series, and Cisco 7500 series routers
Internet Group Management Protocol (IGMP) is a protocol used by IP v4 systems to report IP multicast
group memberships to neighboring multicast routers. On networks with hosts directly attached, IGMP,
Version 3 (IGMP v3) adds support for “source filtering,” which enables a multicast receiver to signal to
a router which groups it wants to receive multicast traffic from, and from which sources this traffic is
expected. Based on this membership information, Cisco IOS software only forwards traffic that is
requested by the host (or by other routers via Protocol Independent Multicast (PIM)) to that network.
In addition to restricting traffic on the network of the receiver host, IGMP v3 membership information
may also be propagated to multicast routing protocols to enable the forwarding of traffic from permitted
sources or to restrict traffic from denied sources along the entire multicast data delivery path.
In the Source Specific Multicast feature, introduced in Cisco IOS Release 12.1(5)T, hosts must
explicitly include sources when joining a multicast group (this is known as “channel subscription”).
IGMP v3 is the industry-designated standard protocol for hosts to signal channel subscriptions in SSM.