Common Open Policy Service
Encyclopedia
The Common Open Policy Service (COPS) Protocol is part of the internet protocol suite
as defined by the IETF's RFC 2748. COPS specifies a simple client/server model for supporting policy control over Quality of Service
(QoS) signaling protocols (e.g. RSVP
). Policies are stored on servers, and acted upon by Policy Decision Points (PDP), and are enforced on clients, also known as Policy Enforcement Points (PEP). There are two models of COPS: The Outsourcing Model and the Provisioning Model, considered from the view of the client or PEP.
The Outsourcing Model is the simplest COPS implementation. In this model, all policies are stored at the PDP. Whenever the PEP needs to make a decision, it sends all relevant information to the PDP. The PDP analyzes the information, makes the decision, and relays it to the PEP. The PEP then simply enforces the decision.
In the Provisioning Model, see RFC 3084 COPS Usage for Policy Provisioning (COPS-PR), the PEP reports its decision-making capabilities to the PDP. The PDP then downloads relevant policies on to the PEP. The PEP can then make its own decisions based on these policies. The Provisioning Model uses the Policy Information Base as a repository of the policies.
The COPS-MAID Internet Draft introduces QoS extensions to the protocol for Multi-Access environment.
See http://www-staff.it.uts.edu.au/~simmonds/BB.htm for links to some COPS implementations.
Internet protocol suite
The Internet protocol suite is the set of communications protocols used for the Internet and other similar networks. It is commonly known as TCP/IP from its most important protocols: Transmission Control Protocol and Internet Protocol , which were the first networking protocols defined in this...
as defined by the IETF's RFC 2748. COPS specifies a simple client/server model for supporting policy control over Quality of Service
Quality of service
The quality of service refers to several related aspects of telephony and computer networks that allow the transport of traffic with special requirements...
(QoS) signaling protocols (e.g. RSVP
Resource Reservation Protocol
The Resource Reservation Protocol is a Transport Layer protocol designed to reserve resources across a network for an integrated services Internet. RSVP operates over an IPv4 or IPv6 Internet Layer and provides receiver-initiated setup of resource reservations for multicast or unicast data flows...
). Policies are stored on servers, and acted upon by Policy Decision Points (PDP), and are enforced on clients, also known as Policy Enforcement Points (PEP). There are two models of COPS: The Outsourcing Model and the Provisioning Model, considered from the view of the client or PEP.
The Outsourcing Model is the simplest COPS implementation. In this model, all policies are stored at the PDP. Whenever the PEP needs to make a decision, it sends all relevant information to the PDP. The PDP analyzes the information, makes the decision, and relays it to the PEP. The PEP then simply enforces the decision.
In the Provisioning Model, see RFC 3084 COPS Usage for Policy Provisioning (COPS-PR), the PEP reports its decision-making capabilities to the PDP. The PDP then downloads relevant policies on to the PEP. The PEP can then make its own decisions based on these policies. The Provisioning Model uses the Policy Information Base as a repository of the policies.
The COPS-MAID Internet Draft introduces QoS extensions to the protocol for Multi-Access environment.
See http://www-staff.it.uts.edu.au/~simmonds/BB.htm for links to some COPS implementations.