server.mrcp2.sip.transport.qos

Differentiated Services (DSCP) IP header setting used by Nuance Speech Server to match the values expected by the gateway.

Value

Integer: decimal DSCP value representing the quality of service desired.

DEFAULT: 96 (CS3)

The DSCP value occupies the highest 6 bits of an IP header called DiffServ. (The two lowest bits are a different field, which is not settable by Speech Server.)

Note: Although the parameter takes a decimal value, the IP header displays the value as a hexadecimal number (for example, 184 appears as 0xB8).

How to set

If using the Management Station, set on the Speech Server service. If not using Management Station, set in an NSS configuration file (user-NSSxx.txt).

Usage

Seldom changed.

The parameter accepts DSCP codes shifted to their position in the former TOS IP header (shifted 2 bits left).

To set the parameter, take the desired DSCP value, multiply it by 4, and set that value. Anything that you set for the lower two bits of this parameter has no effect.

Note: Controlling DSCP is supported only for Linux systems.

DSCP (Differentiated Services Code Point) replaces TOS (type of service) and other QoS (quality of service) mechanisms. DSCP is a group of six bits that announce the quality of service desired for IP packets. Speech Server can set this field to match the value desired by the telephony gateway. Higher values represent higher IP priority.

Related parameters