4 位优先级"字段的描述反映了已被 RFC 2460 (Solaris 8 执行 RFC 2460) 淘汰了的 RFC 1883。 结果,优先级字段已被 8 位通信类字段所替换。 优先级一节应替换为以下的通信类一节。
Originating nodes and forwarding routers can use the 8-bit Traffic Class field in the IPv6 header to identify and distinguish between different classes or priorities of IPv6 packets.
The following general requirements apply to the Traffic Class field.
The service interface to the IPv6 service within a node must provide a means for an upper-layer protocol to supply the value of the Traffic Class bits in packets that were originated by that upper-layer protocol. The default value must be zero for all 8 bits.
Nodes that support a specific use of some or all of the Traffic Class bits can change the value of those bits in packets that they originate, forward, or receive, as required for that specific use. Nodes should ignore and leave unchanged any bits of the Traffic Class field for which they do not support a specific use.