Frame Relay PVC Oversubscription
Figure 15-1
1.544-Mbps Frame Relay circuit. The network has 18 remote sites with 128-kbps Frame Relay circuits.
The aggregate bandwidth is 2.3 Mbps:
The Central Site is oversubscribed by 50 percent. However, this configuration is valid because:
•
•
•
Figure 15-1
Aggregate bandwidth
of remotes exceed egress
Central site
Feature History for Frame Relay PVC Oversubscription
Cisco IOS Release
Release 12.3(7)XI1
Release 12.2(28)SB
Cisco 10000 Series Router Quality of Service Configuration Guide
15-8
shows a Frame Relay network that is oversubscribed. In the figure, the Central Site has a
128 kbps * 18 sites = 2.3 Mbps
The remote users require only e-mail access and the ability to transfer small files using File Transfer
Protocol (FTP).
All of the remote sites are unlikely to try to use all of the available bandwidth at the same time.
All of the remote sites are unlikely to simultaneously access the network.
Oversubscribed Frame Relay Network
18 Frame Relay
Access Devices
(FRAD)
1.544 Mbps
Description
The Frame Relay PVC oversubscription feature was
introduced on the PRE2.
This feature was integrated in Cisco IOS
Release 12.2(28)SB for the PRE2.
Chapter 15
128 kbps
Frame Relay
Network
Oversubscribing Physical and Virtual Links
Required PRE
PRE2
PRE2
OL-7433-09