Bandwidth Management Examples - ZyXEL Communications ZYWALL USG 20 Manual

Maximize Bandwidth Usage Effect
With maximize bandwidth usage enabled, after each server gets its configured
rate, the rest of the available bandwidth is divided equally between the two. So
server A gets its configured rate of 300 kbps and server B gets its configured rate
of 200 kbps. Then the ZyWALL divides the remaining bandwidth (1000 - 500 =
500) equally between the two (500 / 2 = 250 kbps for each). The priority has no
effect on how much of the unused bandwidth each server gets.
So server A gets its configured rate of 300 kbps plus 250 kbps for a total of 550
kbps. Server B gets its configured rate of 200 kbps plus 250 kbps for a total of
450 kbps.
Table 129 Maximize Bandwidth Usage Effect
POLICY CONFIGURED RATE
A
B
Priority and Over Allotment of Bandwidth Effect
Server A has a configured rate that equals the total amount of available
bandwidth and a higher priority. You should regard extreme over allotment of
traffic with different priorities (as shown here) as a configuration error. Even
though the ZyWALL still attempts to let all traffic get through and not be lost,
regardless of its priority, server B gets almost no bandwidth with this
configuration.
Table 130 Priority and Over Allotment of Bandwidth Effect
POLICY
A
B
Finding Out More
• See Section 7.5 on page 120
policies with bandwidth restrictions.
• See DSCP Marking and Per-Hop Behavior on page 299
marking.

28.1.3 Bandwidth Management Examples

Bandwidth management is very useful when applications are competing for limited
bandwidth. For example, say you have a WAN zone interface connected to an
ADSL device with a 8 Mbps downstream and 1 Mbps upstream ADSL connection.
ZyWALL USG 20/20W User's Guide
MAX. B. U. PRIORITY ACTUAL RATE
300 kbps
200 kbps
CONFIGURED RATE
1000 kbps
1000 kbps
for an example of how to set up web surfing
Chapter 28 Bandwidth Management
Yes 1
Yes 2
MAX. B. U. PRIORITY
Yes 1
Yes 2
550 kbps
450 kbps
ACTUAL RATE
999 kbps
1 kbps
for a description of DSCP
457