ICAP at Network Edge Caches USENIX Special Workshop on Intelligence at the Network Edge ICAP at Network Edge Caches Gary Tomlinson Novell, Inc. March 20, 2000

ICAP Backgrounder Hooks external application servers into the proxy flow ICAP specification http://www.i-cap.org/specification.txt ICAP introduction http://www.i-cap.org/icap5.ppt Origin ICAP Server ICAP Client (Proxy Cache) User

Edge Applications Device translation (distillation) Context mixing Content injection/substitution …….. Content filtering Identity anonymity Content redirecting ……..

Engineering caches for ICAP Buffering Content serialization, idempotency, flow pipeline stalls QoS QoS propagation ICAP server introduced flow latency Triggers Patterns for headers, content Time for streaming media Variations Adaptations with new HTTP Varies or HTTP ETags

Operational Considerations Co-location Bandwidth Latency Security Remote callout programming ICAP Client configuration out of ICAP scope Call outs are URL web server applications Potential Improvements Secure ICAP channel, possibly SSL Signaling channel with standard trigger grammar

Ethical & Social Issues Privacy Access controls Security breaches End to end semantic correctness Intermediary compliance with party interests User Provider Conflict Does transparent adaptations make sense? User Opt-in Provider Opt-in