|  | # Quality of Service (QoS) using Differentiated services | 
|  |  | 
|  | Differentiated services or DiffServ is a mechanism for classifying network traffic and providing quality of service on IP networks. | 
|  | DiffServ uses dedicated fields in the IP header for packet classification purposes. | 
|  | By marking outgoing packets using a Differentiated Services Code Point (DSCP) the network can prioritize accordingly. | 
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|  | The DSCP value on outgoing packets is controlled by the following channel argument: | 
|  |  | 
|  | * **GRPC_ARG_DSCP** | 
|  | * This channel argument accepts integer values 0 to 63. See [dscp-registry](https://www.iana.org/assignments/dscp-registry/dscp-registry.xhtml) for details. | 
|  | * Default value is to use system default, i.e. not set. | 
|  | * Only apply to POSIX systems. |