Rsvp Configuration Example - Cisco WS C4224V 8FXS - 200Mbps Ethernet Switch Software Configuration Manual

Chapter 6 Configuring VoIP
Configure IP Networks for Real-Time Voice Traffic
This command starts RSVP and sets the bandwidth and single-flow limits. The
default maximum bandwidth is up to 75 percent of the bandwidth available on the
interface. By default, the amount reservable by a flow can be up to the entire
reservable bandwidth.
On subinterfaces, RSVP applies to the more restrictive of the available
bandwidths of the physical interface and the subinterface.
Reservations on individual circuits that do not exceed the single flow limit
normally succeed. However, if reservations have been made on other circuits
adding up to the line speed, and a reservation is made on a subinterface that itself
has enough remaining bandwidth, the reservation will be refused. The reason the
reservation will be refused is because the physical interface lacks supporting
bandwidth.
A Cisco 1750 running VoIP and configured for RSVP requests allocations by
using the following formula:
bps = packet_size + ip/udp/rtp header size x 50 per second
For the codec standard G.729, wherein voice is coded into 8-kbps streams, the
allocation works out to be 24,000 bps. For G.711, the allocation is 80,000 bps.
For more information about configuring RSVP, refer to the "Configuring RSVP"
section of the Network Protocols Configuration Guide, Part 1 for Cisco IOS
Release 12.0 T.

RSVP Configuration Example

The following example enables RSVP and sets the maximum bandwidth to
100 kbps and the maximum bandwidth per single request to 32 kbps. The example
presumes that both VoIP dial peers have been configured.
c4224(config)# interface serial 0/0
c4224(config-if)# ip rsvp bandwidth 100 32
c4224(config-if)# fair-queue
c4224(config-if)# end
After enabling RSVP, you must also use the req-qos dial-peer configuration
command to request an RSVP session on each VoIP dial peer. Otherwise, no
bandwidth is reserved for voice traffic.
c4224(config)# dial-peer voice 211 voip
c4224(config-dial-peer)# req-qos controlled-load
c4224(config)# dial-peer voice 212 voip
c4224(config-dial-peer)# req-qos controlled-load
Catalyst 4224 Access Gateway Switch Software Configuration Guide
6-6
OL-2031-02