Chapter 23 BWM (Bandwidth Management)
ZyWALL ATP Series User’s Guide
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Priority Effect
Here the configured rates total more than the available bandwidth. Because server
A
has higher priority,
it gets up to it’s configured rate (800 kbps), leaving only 200 kbps for server
B
.
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 Zyxel Device 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.
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 Zyxel Device 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.
23.2 The Bandwidth Management Configuration
The Bandwidth management screens control the bandwidth allocation for TCP and UDP traffic. You can
use source interface, destination interface, destination port, schedule, user, source, destination
information, DSCP code and service type as criteria to create a sequence of specific conditions, similar
to the sequence of rules used by firewalls, to specify how the Zyxel Device handles the DSCP value and
allocate bandwidth for the matching packets.
Click
Configuration > BWM
to open the following
screen. This screen allows you to enable/disable
bandwidth management and add, edit, and remove user-defined bandwidth management policies.
Table 170 Priority Effect
POLICY
CONFIGURED RATE
MAX. B. U.
PRIORITY
ACTUAL RATE
A
800 kbps
Yes
1
800 kbps
B
1000 kbps
Yes
2
200 kbps
Table 171 Maximize Bandwidth Usage Effect
POLICY
CONFIGURED RATE
MAX. B. U.
PRIORITY
ACTUAL RATE
A
300 kbps
Yes
1
550 kbps
B
200 kbps
Yes
2
450 kbps
Table 172 Priority and Over Allotment of Bandwidth Effect
POLICY
CONFIGURED RATE
MAX. B. U.
PRIORITY
ACTUAL RATE
A
1000 kbps
Yes
1
999 kbps
B
1000 kbps
Yes
2
1 kbps