In-Band Quality-of-Service Signaling to Endpoints that Enforce Traffic Policies at Traffic Sources Using Policy Messages Piggybacked onto DiffServ Bits

摘要

IP packets are scheduled at source devices such as cell phones on a private network that connect to the Internet at an edge device. A private traffic controller by the edge device detects pre-Internet congestion on the private network. The private traffic controller uses in-band piggybacked signaling of policy changes by intercepting return packets to the source devices and modifying bits such as DSCP bits in the header. Source traffic controllers in the source devices read the modified DSCP bits and implement specified policy changes, dropping or delaying packets at the source device before transmission. Congestion on RF links from cell phones is reduced by the source traffic controllers dropping packets before transmission. The source device limits or drops future packets in response to the policies signaled by the DSCP bits. Rather than indicate the existing packet's priority, private DSCP bits signal policy changes to the source device.