TOS/DSCP对照表

IP Type of Service

This classification type is based on an exact match of the one-byte ToS/DSCP field contained in the IP header of a frame. The ToS (Type of Service) or DSCP (Diffserve Codepoint) value is defined by an 8-bit hexadecimal number between 0 and FF. Enter

a value or click Select to open a window where you can generate a hex value. For

information on how to generate a ToS or DSCP value, see ToS/DSCP

Configuration window.

Type of Service can be used by applications to indicate priority and Quality of Service for each frame. The level of service is determined by a set of service parameters

which provide a three way trade-off between low-delay, high-reliability, and

high-throughput. The use of service parameters may increase the cost of service. In many networks, better performance for one of these parameters is coupled with

worse performance on another. Except for very unusual cases, at most, two of the parameters should be set.

"IP precedence 使用前3bit; ToS 使用4-7 bit, 最后一位备用;"

"DSCP 使用0-5bit, 最后两位备用;"

For a ToS value, the 8-bit hexadecimal number breaks down as follows:

Bits 0-2: Precedence

Bit 3: 0=Normal Delay, 1=Low Delay

Bit 4: 0=Normal Throughput, 1=High Throughput

Bit 5: 0=Normal Reliability, 1=High Reliability

Bits 6-7: Explicit Congestion Notification

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