Channels between routers for use in packet routing via payload inspection. The channels constitute logical connections between routers and include subjects and attributes. Publishers create channels for routing particular types of content as defined by the subjects and attributes. The publishers also create proxies and notifications on the channels. The channel definitions for routers identify packet or message structures so that the routers can locate attributes in the packets for content-based routing. The routers apply the packet attributes to filters encapsulating subscriptions in order to perform the content-based routing in the network core. The routers also locally cache content, providing distributed caching of content throughout the network core.