RFC 3752 (rfc3752) - Page 2 of 14

Open Pluggable Edge Services (OPES) Use Cases and Deployment Scenarios

RFC 3752                     OPES Scenarios                   April 2004


       3.3.  Enterprise environment . . . . . . . . . . . . . . . . .  8
       3.4.  Callout Servers  . . . . . . . . . . . . . . . . . . . .  9
       3.5.  Chaining of OPES data filters and callout servers  . . .  9
             3.5.1.  Chaining along the content path. . . . . . . . .  9
             3.5.2.  Chaining along the callout path. . . . . . . . .  9
   4.  Failure cases and service notification . . . . . . . . . . . . 10
   5.  Security Considerations. . . . . . . . . . . . . . . . . . . . 11
   6.  Informative References . . . . . . . . . . . . . . . . . . . . 11
   7.  Acknowledgements . . . . . . . . . . . . . . . . . . . . . . . 12
   8.  Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . 12
   9.  Full Copyright Statement . . . . . . . . . . . . . . . . . . . 14

1.  Introduction

   The Open Pluggable Edge Services (OPES) [1] architecture enables
   cooperative application services (OPES services) between a data
   provider, a data consumer, and zero or more OPES processors.  The
   application services under consideration analyze and possibly
   transform application-level messages exchanged between the data
   provider and the data consumer.  The execution of such services is
   governed by a set of filtering rules installed on the OPES processor.

   The rules enforcement can trigger the execution of service
   applications local to the OPES processor.  Alternatively, the OPES
   processor can distribute the responsibility of service execution by
   communicating and collaborating with one or more remote callout [6]
   servers.

   The document presents examples of services in which Open Pluggable
   Edge Services (OPES) would be useful.  There are different types of
   OPES services: services that modify requests, services that modify
   responses, and a special case of the latter, services that create
   responses.

   The work also examines various deployment scenarios of OPES services.
   The two main deployment scenarios, as described by the OPES
   architecture [1], are surrogate overlays and delegate overlays.
   Surrogate overlays act on behalf of data provider applications, while
   delegate overlays act on behalf of data consumer applications.  The
   document also describes combined surrogate and delegate overlays, as
   one might find within an enterprise deployment.

   The document is organized as follows: Section 2 discusses the various
   types of OPES services.  Section 3 introduces OPES deployment
   scenarios.  Section 4 discusses failure cases and service
   notification.  Section 5 discusses security considerations.





Barbir, et al.               Informational