Content and Edge Services Networks

1
Content and Edge Services Networks

• Govindan Ravindran
• SOMA Networks, Inc.
• Internet Research Task Force
• 07-Feb-2002

2
Overview

• Content Network Overview
• OPES Network Overview
• OPES Service Execution
• ICAP and IRML
• Service Management Issues
• Proposed Work Items

3
What is a Content Network?
Protocols and appliances created exclusively for
the location, download, and usage tracking of
content.
4
Content vs. Traditional Networks

• Network infrastructure that exists in layers 1
  through 3
• Routing, forwarding, and switching of frames and
  packets
• Routers, switches, bridges, etc.

• Network infrastructure that exists in layers 4
  through 7
• Routing and forwarding of requests and responses
  for content
• Caching proxies, surrogates, delegates, etc.

5
Types of Content Networks

• Caching Proxies
• Server Farms
• Content Distribution Networks (CDN)

6
Caching Proxies
Requests to Origin Servers
Parent Cache Proxy
Parent Cache Proxy
Requests for a.com
Requests for b.com
Edge Cache Proxy
Content requests
Client
7
Server Farm
Content Server
Content Server
Client A requests
Client B requests
L4-L7 Switch
Content requests
Content requests
Client A
Client B
8
Content Distribution Network
Request Routing System
(1) Content request
(2) Content location
1
2
Surrogate
(3) Content request
3
(4) Content response
4
Client B
9
Content Network Overlay
Client
Edge Server
Router
Content Overlay Network
Client
Origin Server
Packet Network
Client
10
What is an Edge Services Network?
An overlay infrastructure which extends
content network to operate on and provide a
value-add to the content to be delivered.
11
OPES - Example Services

• Virus Scanning
• Location Based Services
• Assembling of Personalized Web pages
• Content Adaptation for Various Client Devices
• Limited Client Bandwidth Adaptation
• Adaptation of Streaming Media
• Request Filtering
• Language Translation

12
Edge Services Network Overlay
Client
Intermediary
Edge Server
Router
Client
Edge Services Overlay
Content Network
Origin Server
Packet Network
Client
13
OPES - Network Elements
AAA/PDP
Admin Server
Local Exec Environment
Remote Exec Environment
Origin Server
Client
OPES Engine/PEP
OPES Intermediary
Remote Callout Server
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OPES Engine
Call-out Protocols (ICAP, HTTP, etc.)
Remote
Remote
Proxylet
Proxylet
Call-out
Call-out
Remote Exec Environment
Local Exec Environment
Proxylet Library
Stub
Stub
Remote Callout
Proxylet
System
Run-time System
Rule Module
Rule Module
Origin Servers
Rule Processor
Clients
Message Parser
OPES Engine
15
OPES - Service Execution Points
Admin Server
4
3
Origin Server
Client
Intermediary
1
2
Callout Server
16
Internet Content Adaptation Protocol (ICAP)

• A request/response protocol for executing a
  remote procedure call on HTTP messages.
• Supports request and response modification.

17
ICAP - Request Modification
6
5
Origin Server
Client
ICAP Client
4
1
2
3
ICAP Server
18
ICAP - Response Modification
6
3
Origin Server
Client
ICAP Client
2
1
4
5
ICAP Server
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ICAP - Request Modification Example
ICAP Request
REQMOD icap//icap-server.net/server?arg87
ICAP/1.0 Host icap-server.net Encapsulated
req-hdr0, null-body170 GET HTTP/1.1 Host
www.origin-server.com Accept text/html,
text/plain Accept-Encoding compress If-None-Match
xyzzy, r2d2xxxx ICAP/1.0 200 OK Date
Mon, 10 Jan 2000 095521 GMT Server
ICAP-Server-Software/1.0 Connection
close Encapsulated req-hdr0, null-body231 GET
/modified-path HTTP/1.1 Host www.origin-server.co
m Via 1.0 icap-server.net Accept text/html,
text/plain, image/gif Accept-Encoding gzip,
compress If-None-Match xyzzy, r2d2xxxx
ICAP Response
20
Intermediary Rule Mark-up Language (IRML)

• XML-based language used to describe
  service-specific execution rules.
• IRML rules are processed by rule processors on
  Intermediaries.
• IRML rules are matched by evaluating rule
  conditions against the properties of
  incoming/outgoing messages, system and
  environment variables.

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IRML Example
ltrulesetgt ltauthorized-by classcontent-consume
r typeindividualgt ltnamegtA. Becklt/namegt
ltcontactgtlt/contactgt ltidgtlt/idgt
lt/authorized-bygt ltprotocolgtHTTPlt/protocolgt
ltrule processing-point4gt ltproperty
nameContent-Type contextres-msg
matchesdefrgt ltexecutegt
ltservice nameBabelFish Translationgt
lturigtopes//altavista.com/babelfishlt/urigt
lt/servicegt lt/executegt
lt/propertygt lt/rulegt lt/rulesetgt
22
Service Management at Network Edge

• Subscriber Management
• Service Fault Management
• Service Authorization
• Service Accounting
• Service Alerts and Notifications
• Policy-based Service Management

23
OPES - Subscriber Management
S - Service Execution Point
User Profile includes service subscription,
access rate, device capability, content filters,
etc.
Call-out Server
6
5
7
2
Origin Server
S1
Surrogate
Delegate
9
8
S2
User profile,
Updates
3
4
1
10
Rule Modules
User
PCS Server
Service Manager
Agent
(ICAP Server)
User Profile
(IRML enabled)
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OPES - Service Authorization
Call-out Server
6
5
7
2
Origin Server
S1
Surrogate
Delegate
9
8
S2
3
4
1
10
User
Service Manager
Agent
(ICAP Server)
25
OPES - Service Fault Management
Call-out Server
Call-out Server
10
9
6
5
11
2
Origin Server
S1
Surrogate
Delegate
13
S2
S2
12
3
8
7
4
1
14
User
Service Manager
Agent
(ICAP Server)
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OPES - Service Accounting
SDR - Service Detailed Record
Call-out Server
6
5
7
2
Origin Server
Surrogate
Delegate
9
8
User profile,
Updates
3
4
1
10
Accounting Server
User
Service Manager
Agent
(ICAP Server)
SDR
27
OPES - Service Notification
Call-out Server
6
5
7
2
Origin Server
Surrogate
Delegate
9
8
User profile,
Updates
3
4
1
10
Rule Modules
User
Service Manager
Content Provider Service Manager
Agent
(IRML Enabled PEP)
Alerts/ Notification
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OPES - Server Load Balancing
Call-out Server A
Call-out Server C
Call-out Server B
7
2
Origin Server
Surrogate
Delegate
9
8
3
4
1
10
Call-out servers load and usage statistics
User
Service Manager
Agent
(IRML Enabled PEP)
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IAB Considerations

• One party consent explicit authorization of one
  of the application layer end-points.
• Assist content providers to detect and respond to
  inappropriate client-centric actions by
  intermediaries.
• Assist end-users to detect inappropriate behavior
  by intermediaries.
• Access to non-OPES version of the content.

30
Work Items

• OPES Service Management Informational RFC
• OPES Service Management Framework Definition
• OPES Service Manager Interfaces Definition
• IRML Service Manager Extensions