Chapter 15 • IPv6 Quality of Service (QoS) 265
different (appropriate) ways. Routers may also be configured to break
up these classes into subaggregations to be treated slightly differently.
For example, a router might be configured to forward premium-service
packets from preferred customers over links that are more reliable
than premium-service packets coming from customers subscribing to
a “budget-premium” service.
Diffserv brings with it the ability to create network service policies specific
to a single router, some part of a network, or an entire diffserv routing
domain. As long as their policies don’t affect the ability to provide guar-
anteed QoS, network providers can fine-tune their diffserv routers to
differentiate how they treat packets.
The