Download Active Networks

Active Networks – The
Network Future
By
Samatha Gangapuram
Prashant Shanti Kumar
Harish Kumar Maringanti
Assigned Unenviable task
 What
 Why
 How
 Where
Active Networks – What ?
No general agreement beyond buzz phrases.
“Active networks explore the idea of
allowing routing elements to be
extensively programmed by the
packets passing through them.”
Legacy Vs Active
Legacy Networks
Active Networks
 Passive packet.
 Rely on agreement
about protocols.
 Functionality built
into each router.
 Change is a long and
wrenching process.
 Active Packet.
 General agreement on
model of computation.
 Functionality in each
packet.
 Improved resilience to
change.
AN - Services
Active Networks – Why ?
Rapid deployment and development.
Creating and Tailoring network
services.
Better performance.
Open to deploy and administer.
Active Networks – How ?
AN Paradigms
 Programmable Switch Model
 Capsule Model
 Ad – hoc Model
Active Networks – How ?
Programmable Switch :
 Code is first transferred to the
nodes, out – of – band.
 Packets are treated as data or
input to the code.
Active Networks – How ?
Capsule Model :
 Each packet is a program.
 Each intermediate node
executes the packet.
Active Networks – How ?
Ad – hoc Model :
 Packet contains flags.
 Node contains in-built routines.
 Based on flag, routines are executed.
A N - Terminologies
 User Application (UA)
 Active Application (AA)
 Execution Environment (EE)
 Node Operating System (NodeOS)
NodeOS
 The NodeOS is the base layer of any AN
architecture.
 It manages the resources of the active
node and co-ordinates the resource
demands.
 NodeOS is also responsible for the
enforcement of security policies.
Examples
SANE OS, JANOS, SCOUT, ExoKernel
EE
Nerve Center of the Active Node
 Responsible for all aspects of user-network
interface.
 Nature of programming model and
abstractions supported.
 Addressing and Naming facilities.
Examples
SmartPackets, ANTS, CANE
AA
 AA is a program and associated state capable
of executing one or more active activities in a
node, to perform some particular service.
 AA is necessarily “portable” and dynamically
installable or removable.
Examples
Active Reliable Multicasts, Protocol
Boosters, Active Congestion Control.
A N - Architecture
App 1
App 2
Execution
Environment A
App 3
Execution
Environment B
App 1
App 4
Execution
Environment A
App 3
Execution
Environment B
Node OS
Node OS
Transmission
Facilities
Packet Transition
I P UDP ANEP
EE 1
ANEP UDP IP
I P UDP
UDP
IP
IP
IP
IP
EE 2
ANEP
ANEP IP
IP
IP
IP
TCP
EE 3
TCP
IP
Implementation Challenges
The network should be usable
The network should have high flexibility
The implementation should be secure
The network should have high performance
Killer Arguments

Efficiency

Resource Allocation

Security
Efficiency
Hiccups:
 Bandwidth demand is growing faster than
CPU speed – bad idea to execute arbitrary
programs on packets.
 Most programming languages are interpreted
– JAVA byte code, plain interpreter.
Cure:
Don’t propose AN for the core of the Internet.
Use just-in-time compilation, native code.
Hybrid architectures (high speed AN!)
Resource Allocation
Hiccups:
 Fairness in queuing is a problem.
 Cannot guarantee QoS.
 Cannot control Looping packets.
Cure:
Provide distributed control (Scaling).
resource reservation in advance, resource
preemption.
Limit capabilities of the active packet.
Security
Security cannot be limited to peripheral
nodes.
Possible threats:
Overload based Denial of Service
Unauthorized access to the exposed
control plane.
Secure Node doesn’t mean Secure
Network.
Security at NodeOS
 Security Enforcement through Authorizations.
 Authorization policies are expressed in terms
of Access Control Lists, which is a logical
3 - tuple of the form : <resource, user,
permissions>
 NodeOS has a security policy database and a
policy enforcement engine.
Security at EE
Each EE has it's own protection policy,
possibly a security database and an
enforcement engine.
The programming model that an EE
supports must also be restricted to ensure
network security.
No broad consensus on the division of
responsibility for policy enforcement
between the NodeOS and the EE.
Security in SwitchWare

Uses ALIEN active loader.

Code Modules loaded on the fly.

Restricts access using namespaces.

Uses a language specification called CAML.
AN – APPLICATIONS
Network Management
Multicasting
Caching
Active Congestion Control
Security
Network Management
No polling required
"Patrol" and "first-aid" packets can track a
problem and rectify it respectively.
Code moved to node rather than data to
management center
Example:Delegated Management.
Decentralization helps in scalability, reducing
delays from responses and effective
bandwidth utilization.
Multicasting
Active internal nodes elegantly solve many
current problems such as:
 NACK implosion.
 Concentrated load of retransmissions.
Duplication of packets.
Example: ARM
Suppression of NACK & effective retransmission
Active Congestion Control
Selective dropping of units, packets or
cells can be held very efficiently.
Multi-stream interaction.
Example: APCI
Backward compatibility with non-active
nodes & on the fly routing employed.
Caching
 Tradeoff between network based storage &
bandwidth.
 Location & time of storage crucial.
Example:
Self-organizing wide-Area Network
caches: small number of caches within
routers form large virtual cache.
Security
 Node – Packet conflict.
 Node security by authentication of active
packets & PCC(Proof Correct Code).
 Packet security by Fault-tolerance &
Encryption.
Example:SANE
AN - Services





Video on Demand
VPN
Multimedia Conferencing
VoIP / IP Telephony
Active Firewalling
AN - Services
New Content-type or
Redirection Header
Request
Dynamic Proxy
Server
WebCache Proxylet
Remote Method
Invocation Call
Dynamic Proxy
Server
Audio Transcoder
RTP Streamed Audio
Request
Audio
Response
Audio File
Response
Audio File
Request
Proxylet
Response Proxylet
Request
Request
Web
Browser
Response
Web Cache
Web Server
Proxylet Server
“Retrofitting" AN to IP
The Active IP Option:

Option in the IP header alerts the router to
look at the packet payload more closely.
Active Network Encapsulation Protocol
(ANEP):

Adds a header that directs the router.
AN & Legacy
SmartPackets – A Case Study
Uses Capsule model: Code with IP packet
Programs must be completely self-contained.
Operating environment provides security.
Languages:
Sprocket – A high level language
Spanner – An assembly level language
SmartPackets – A Case Study
Uses ANEP to fit with Legacy Networks
NodeOs – JanOs
EE
– CANES/ASP
AA
Network Management
SmartPackets – A Case Study
Network Management
Defines 4 types of packets:
 Program
 Data
 Error
 Message
SmartPackets – A Case Study
Security
For Nodes:
 Authentication of packet
 Cryptographic hash of non-mutable fields
For packets:
 Redirection
 Encryption
SmartPackets – A Case Study
Limitations
 Packet size
 Applications adaptability
Scope
Extending for other applications
Current Work

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
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Active Nets at DARPA
ActiveNets at MIT
ANTS at Washington
SwitchWare at UPenn
JANOS & OSkit at Utah
Liquid Software at Arizona
Panda at UCLA
NetScript at Columbia
CANES at Georgia Tech
Smart Packets at BBN
Conclusion
Is Active Network really the future ?
References
Darpa
http://www.darpa.mil/ito/psum1999/J044-0.html
Switchware
http://www.cis.upenn.edu/~switchware/
CANES
http://www.cc.gatech.edu/projects/canes/
www.ieee.org
www.citeseer.com