[ CCode ( type_id = "g_ipv6_tclass_message_get_type ()" ) ] [ Version ( since = "2.88" ) ] publicsealedclassIPv6TclassMessage : SocketControlMessage
Contains the Traffic Class byte of an IPv6 header.
This consists of the DSCP field as per [RFC 2474](https://www.rfc-editor.org/rfc/rfc2474section-3), and the ECN field as per
[RFC 3168](https://www.rfc-editor.org/rfc/rfc3168section-5).
It may be received using [method@Gio.Socket.receive_message] over UDP sockets (i.e. sockets in the `G_SOCKET_FAMILY_IPV6` family with
`G_SOCKET_TYPE_DATAGRAM` type). The message is not meant for sending. To set Traffic Class field to be used in datagrams sent on a [
class@Gio.Socket] use: ```c g_socket_set_option (socket, IPPROTO_IPV6, IPV6_TCLASS, <TC value>, &error); ```