ZyXEL Communications 802.11g Wireless ADSL2+ 4-port VoIP IAD P-2602HWNLI - Manual (Page 277)

P-2602HWNLI User’s Guide
Chapter 19 Bandwidth Management 277
• Each class gets up to its budgeted bandwidth. The administration class only uses 1024
kbps of its budgeted 2048 kbps.
• The ZyXEL Device divides the total 3072 kbps total of unallocated and unused
bandwidth equally among the other classes. 1024 kbps extra goes to each so the other
classes each get a total of 3072 kbps.
19.6.3 Bandwidth Management Priorities
Traffic with a higher priority gets through faster while traffic with a lower priority is dropped
if the network is congested. The following table describes the priorities that you can apply to
traffic that the ZyXEL Device forwards out through an interface.
19.7 Over Allotment of Bandwidth
You can set the bandwidth management speed for an interface higher than the interface’s
actual transmission speed. Higher priority traffic gets to use up to its allocated bandwidth,
even if it takes up all of the interface’s available bandwidth. This could stop lower priority
traffic from being sent. The following is an example.
If you use VoIP and NetMeeting at the same time, the device allocates up to 500 Kbps of
bandwidth to each of them before it allocates any bandwidth to FTP. As a result, FTP can only
use bandwidth when VoIP and NetMeeting do not use all of their allocated bandwidth.
Suppose you try to browse the web too. In this case, VoIP, NetMeeting and FTP all have higher
priority, so they get to use the bandwidth first. You can only browse the web when VoIP,
NetMeeting, and FTP do not use all 1000 Kbps of available bandwidth.
Table 106 Bandwidth Management Priorities
PRIORITY DESCRIPTION
High Typically used for voice traffic or video that is especially sensitive to jitter (jitter is the
variations in delay).
Mid Typically used for “excellent effort” or better than best effort and would include important
business traffic that can tolerate some delay.
Low This is typically used for non-critical “background” traffic such as bulk transfers that are
allowed but that should not affect other applications and users.
Table 107 Over Allotment of Bandwidth Example
BANDWIDTH CLASSES, ALLOTMENTS PRIORITIES
Actual outgoing bandwidth available on the interface: 1000 kbps
Root Class: 1500 kbps (same
as Speed setting)
VoIP traffic (Service = SIP): 500 Kbps High
NetMeeting traffic (Service = H.323): 500 kbps High
FTP (Service = FTP): 500 Kbps Medium