1. 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

2. ICAP Backgrounder
Hooks external application servers into the proxy flow
ICAP specification
ICAP introduction
Origin
ICAP
Server
ICAP Client
(Proxy Cache)
User

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

4. 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

5. 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

6. 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