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Heavy and lightweight dynamic network
services: challenges and experiments for
designing intelligent solutions in evolvable next
generation networks
Laurent Lefèvre
INRIA / LIP (UMR CNRS, INRIA, ENS, UCB)
[email protected]
WAGEN Workshop - Jiuzhaigou - April 8, 2005
-
Challenges

Active networks : programmable network
equipments which allow deployment of
heterogeneous services




in data plan (heavy services)
In control / management plans (lightweight services)
How to urbanize networks with autonomous
dynamic services ?
How to efficiently manage such heterogeneous
services for providing efficient solutions inside
the network ?
Patterns

Robustness



Personnalized



Best effort services
Garanted services
Generic services
Dedicated services (application, user, stream…)
TTL

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One-usage service
Persistant services
Roadmap
Urbanization of dynamic network services
 Lightweight network functionalities
 Cluster-based network equipments
 Load balancing strategies for
heterogeneous services

Where to map dynamic
autonomous network services?
Urbanization is an open problem
 Mixes networking aspects with service
composition

Access networks
 Peering points
 Front end of clusters
 LAN ?

Service on data path
Proxy mode
 Dynamic deployment

Replicated network service
Same service replicated on several
network equipments
 On the fly deployment with data streams

Distributed network
autonomous service
Service composition
 Allow pipelined approach
 Dealing with fault tolerance / load
balancing

Unique service out of the data
path
Dedicated equipment (legacy solution)
 Requires intelligent forwarding

Distributed service outside the
data path

Requires sensors to evaluate cost of
multiple fwd operations

Proposing a generic active environment
able to handle heterogeneous services :


The Tamanoir project
Supporting requirements of current
networks (Gbits)
Tamanoir Architecture : adapted
for heterogeneous services

Resources consuming services :
distributed storage, streams
adaptation, on the fly
compression, cryptography…

Services deployment / linked
with middleware : reliable
multicast…

Middle services : content based
routing, QoS...

Light network services : packet
marking, QoS…
Distributed resources
Execution
environment
Kernel
NIC (Programmable)
Active service deployment
From application / middleware
 From TAN
 From network service Broker

Tamanoir Active Node (TAN)
Execution environment
Performance evaluation of middle services
Solution / Problem
Simple Java service in user space can
support up to 450 Mbits !  (we eat the ants ! )
 A stand-alone active node is not enough
to fully support and apply active service to
Gbit streams 
 Need to put lightweight network
functionalities close to the network
 Explore kernel services

Distributed resources
Execution
environment
Kernel
NIC (Programmable)
Kernel support
for active node
Kernel Support
•
Module inside Linux kernel : using netfilter
Filtering ANEP packets
• Allowing packet to cross the active node
through the kernel space
• Efficiently put ANEP packets inside the
service in user space
•
Netfilter


Protocols define hooks on the packet way
inside IP stack
Associate hooks and personalized
applications /services
NF_IP_POST_ROUTING
NF_IP_FORWARD
1
Routing
3
4
Routing
2
NF_IP_LOCAL_IN
Local
process
5
NF_IP_LOCAL_OUT
Communication between active
service and OS module


A Tamanoir active service : a java part + kernel module
Message control / parameters
Performance evaluation
Solution / Problem
Kernel active services greatly reduce
latency for transient packets 
 Only applicable to lightweight network
functionalities (state, CPU consumption..)

 Reduce portability of active services
 What about CPU consuming services ?

Distributed resources
Execution
environment
Kernel
NIC (Programmable)
Cluster-based
active node
Tamanoir architecture : on a
cluster
Pushing performances
Improving performances of active
nodes : using clustering technology
 Linux Virtual Server
 Strategies :

Round robin
 Least connected

Performance evaluation
Solution / Problem



We support a full Gbit streams with a small
cluster based Tamanoir active node ! 
We need more resources for CPU consuming
active services
How to balance workload between internal
nodes of an active node without knowing length
of streams and needed services ?
Feedback stream based load
balancing policy (FBSb)


Needs dynamic strategies
for heterogeneous
deployment
FBSb


Front-end machine with
updated “weight” table (CPU
and memory consumption of
back-end machines)
Back-end machines with
feedback agents and sensors
Experiments

Heavy service (3-DES encryption) : this service
makes an intensive use of CPU (1 stream
calling this service saturates a CPU, in our test
implementation);

Medium service (stateful traffic analysis) : this
service uses the CPU in a less intensive way,
but its impact is not transparent (3-4 streams
calling this service saturate a CPU, in our test
implementation).
Experiments

200: composed by 1 stream calling a service of
encryption and 11 streams calling for a traffic analysis
with different delays of arrival of 1 second (201), 2
seconds (202) and 5 seconds (205).

300: composed by 4 streams calling a service of
encryption and 8 streams calling for traffic analysis.
with different delays of arrival of 0 second (300), 1
second (301) and 2 seconds (302).
Experiments : FBSb, RR, LC
Test
FBSb FBSb FBSb RR
RR
RR
LC
LC
LC
MAX
AVG
MIN
MAX
AVG
MIN
AVG
MIN
MAX
201 38.2 20.2 15.9 43.2 20.1 15.5 38.5 20.3 15.4
202 33.3 20
15.7 37.4 20.1 15.4 36.4 20.1 15.4
205 32.9 19.4 15.5 38.8 19.6 15.4 37.3 19.6 15.4
300 52
24.1 16.1 93.6 26
15.4 64.6 25.5 16.3
301 50.8 24.6 15.4 90.3 26.9 16.1 64
25.6 15.4
302 50.9 23.2 15.3 92.9 25.5 15.9 57.8 25
15.6
RR and LC : efficient if homogeneous dynamic services
 FBSb : efficient when heterogeneous deployment

Conclusions and future works

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We propose a gigabit supporting software based active node
using kernel module deployment and cluster
Providing load balancing support inside cluster-based active
equipments is a mandatory aspect for performances
Research could also benefit for network processors technology /
programmable network interface cards
Deployment of large scale active/programmable platform based
on emulation : French Grid5000 project
http://www.ens-lyon.fr/LIP/RESO/Software/Tamanoir