User`s guide
Table Of Contents
- VMG8924-B10A and VMG8924- B30A Series
- User’s Guide
- Technical Reference
- Network Map and Status Screens
- Broadband
- Wireless
- Home Networking
- 7.1 Overview
- 7.2 The LAN Setup Screen
- 7.3 The Static DHCP Screen
- 7.4 The UPnP Screen
- 7.5 Installing UPnP in Windows Example
- 7.6 Using UPnP in Windows XP Example
- 7.7 The Additional Subnet Screen
- 7.8 The STB Vendor ID Screen
- 7.9 The 5th Ethernet Port Screen
- 7.10 The LAN VLAN Screen
- 7.11 The Wake on LAN Screen
- 7.12 Technical Reference
- Routing
- Quality of Service (QoS)
- Network Address Translation (NAT)
- Dynamic DNS Setup
- Interface Group
- USB Service
- Power Management
- Firewall
- MAC Filter
- Parental Control
- Scheduler Rule
- Certificates
- VPN
- Voice
- Log
- Traffic Status
- VoIP Status
- ARP Table
- Routing Table
- IGMP/MLD Status
- xDSL Statistics
- 3G Statistics
- User Account
- Remote Management
- TR-069 Client
- TR-064
- SNMP
- Time Settings
- E-mail Notification
- Logs Setting
- Firmware Upgrade
- Configuration
- Diagnostic
- Troubleshooting
- Customer Support
- Setting up Your Computer’s IP Address
- IP Addresses and Subnetting
- Pop-up Windows, JavaScripts and Java Permissions
- Wireless LANs
- IPv6
- Services
- Legal Information
- Index

Chapter 9 Quality of Service (QoS)
VMG8924-B10A and VMG8924-B30A Series User’s Guide
154
Token Bucket
The token bucket algorithm uses tokens in a bucket to control when traffic can be transmitted. The
bucket stores tokens, each of which represents one byte. The algorithm allows bursts of up to b
bytes which is also the bucket size, so the bucket can hold up to b tokens. Tokens are generated
and added into the bucket at a constant rate. The following shows how tokens work with packets:
• A packet can be transmitted if the number of tokens in the bucket is equal to or greater than the
size of the packet (in bytes).
• After a packet is transmitted, a number of tokens corresponding to the packet size is removed
from the bucket.
• If there are no tokens in the bucket, the Device stops transmitting until enough tokens are
generated.
• If not enough tokens are available, the Device treats the packet in either one of the following
ways:
In traffic shaping:
• Holds it in the queue until enough tokens are available in the bucket.
In traffic policing:
•Drops it.
• Transmits it but adds a DSCP mark. The Device may drop these marked packets if the network
is overloaded.
4 4 2 010110
010100
010010
010000
5 5 3 011110
011100
011010
011000
<250
6 6 4 100110
100100
100010
100000
5 101110
101000
7 7 6 110000
111000
7
Table 55 Internal Layer2 and Layer3 QoS Mapping
PRIORITY
QUEUE
LAYER 2 LAYER 3
IEEE 802.1P USER
PRIORITY
(ETHERNET
PRIORITY)
TOS (IP
PRECEDENCE)
DSCP
IP PACKET
LENGTH (BYTE)