Common Open Policy Service
The Common Open Policy Service ( COPS ) is the “language of routers ”. Routers have to coordinate with each other whether they can comply with an RSVP request (time-limited reservation of a certain minimum bandwidth) or not. It is therefore possible that policy data can be exchanged between a policy client (Policy Enforcement Points, PEPs = requesting router) and a policy server (Policy Decision Point, PDP = requested router) (The Resource Reservation Protocol (RSVP) must be implemented on client and server ).
Classification in protocol family
Common Open Policy Service is part of the Internet protocol family and was published by the IETF (Internet Engineering Task Force) as a policy protocol under the name Common Open Policy Service as an Internet draft and is now available in the form of RFC 2748 . This is a log of the application layer , which is the port 3288 ( TCP used).
(MIBs: iso.org.dod.internet.mgmt.mib-2.copsClientMIB - 1.3.6.1.2.1.89)
Fig: COPS header classified