Specifications

78
Release Notes for Cisco 7000 Family for Cisco IOS Release 12.1 T
78-10811-05
New and Changed Information
Frame Relay Switching Enhancements
Platforms: Cisco 7200 series and Cisco 7500 series routers
The Frame Relay Switching Enhancements feature enables a router in a Frame Relay network to be used
as a Frame Relay switch. This feature provides the following functionality:
Traffic Shaping on Switched PVCs
You can now configure Frame Relay traffic shaping on switched permanent virtual connections (PVCs).
By applying traffic shaping to switched PVCs, you enable a router to be used as a Frame Relay port
concentrator in front of a Frame Relay switch. The Frame Relay switch shapes the concentrated traffic
before sending it into the network.
Frame Relay Switching over ISDN B-Channels
The Frame Relay Switching Enhancements feature enables you to transport Frame Relay data over
ISDN so that small offices can be hubbed out of larger offices rather than connecting them directly to
the core network. The hub router acts as a Frame Relay switch, switching between ISDN and serial
interfaces.
Traffic Policing on UNI DCE
The Frame Relay Switching Enhancements feature brings traffic policing functionality to user to
network interface data communications equipment (UNI DCEs) in Frame Relay networks. When
enabled on the interface, policing prevents traffic congestion by discarding or setting the discard
eligible (DE) bit on packets that exceed specified traffic parameters.
Congestion Management on Switched PVCs
The Frame Relay Switching Enhancements feature enables a router in a Frame Relay network to
manage outgoing traffic congestion on switched PVCs. When Frame Relay congestion management is
enabled, the router manages congestion by setting BECN and FECN bits on packets, and by discarding
packets that are marked with the DE bit and that exceed a specified level of congestion.
Gatekeeper-to-Gatekeeper Redundancy and Load-Sharing
Platforms: Cisco 7200 series routers
The Gatekeeper to Gatekeeper Redundancy and Load-Sharing feature expands the capability that is
provided by the Redundant H.323 Zone Support feature. With the Redundant H.323 Zone Support
feature, the location requests (LRQs) are sent simultaneously (in a “blast” fashion) to all of the
gatekeepers in the list. The gateway registers with the gatekeeper that responds first. Then, if that
gatekeeper becomes unavailable, the gateway registers with another gatekeeper from the list.
The Gatekeeper to Gatekeeper Redundancy and Load-Sharing Mechanism feature enhances this
capability so that you can choose whether the LRQs are sent simultaneously or sequentially
(one-at-a-time) to the remote gatekeepers in the list. If the LRQs are sent sequentially, a delay is
inserted after the first LRQ and before the next LRQ is sent. This delay allows the first gatekeeper to
respond before the LRQ is sent to the next gatekeeper. The order in which LRQs are sent to the
gatekeepers is based on the order in which the gatekeepers are listed (using either the zone prefix
command or the gw-type-prefix command).