Configurable software- -based based Configurable software edge - - PowerPoint PPT Presentation

Configurable software Configurable software-

• based

based edge router architecture edge router architecture

Wajdi LOUATI Badii JOUABER Djamal ZEGHLACHE

Institut National des Télécommunications

4th Workshop on Applications and Services in Wireless Networks, August 2004, Boston, USA

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Outline Outline

• Requirements and challenge

Requirements and challenge

• Control and data plane separation: ForCES

Control and data plane separation: ForCES

• Proposed model

Proposed model

• Performance evaluation and results

Performance evaluation and results

• Conclusion

Conclusion

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Requirements and challenge Requirements and challenge

The edge routers play a major role in NGN:

• Control of connections, sessions, QoS, security, mobility .…
• Achieve internetworking and cooperation

Edge IP router requirements:

• High Flexibility
• Performance
• Scalability

Challenge:

To increase the flexibility and adaptability of routers while at the same time

• ffering higher packet forwarding performance.

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Existing architectural solutions for IP routers Existing architectural solutions for IP routers

• Software-based routers

+ Flexibility: New features are easily added – Performance limitation

Data Plane (IP) Control Plane (BGP, RSVP…)

GPP

PCI NIC NIC NIC

Software Hardware

• ASIC-based routers

+ Very fast – Flexibility problem

• Network processor-based routers

+ Flexibility, Performance, Scalability – Dependent Toolkit, Difficult deployment

Control Plane (BGP, RSVP…)

GPP

PCI

Software Hardware

Data Plane

NIC NIC

Control and data plane separation Control and data plane separation

NP ASIC

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Control and data plane separation Control and data plane separation

Management plane

Configuration, monitoring, provisionning...

Control plane

Routing, Signaling, Discovery ...

COPS, SNMP...

Services APIs Scalable, extensible, interoperable CP to DP interconnect model (ForCES Protocol)

Forwarding plane

Classifiers, Meter, Scheduling, QoS...

NPU NPU NPU NPU

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ForCES (Forwarding and Control Element ForCES (Forwarding and Control Element Separation) Architecture Separation) Architecture

FE resources BGP RSVP …. OSPF ForCES Interface

CE CE CE CE

ForCES Interface Shaper Classifier …. Meter

FE FE FE FE

ForCES Protocol

Data packets ForCES Control messages Data plane Network Element (router) Control plane

• ForCES: Defines and standardizes the required interfaces, protocols and the

exchange of information between the separated planes.

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Software Software-

• based router improvement

based router improvement

• Software router can adopt the

same notion of plane separation

• Data plane can use high

performance software Challenges:

• Which Software?
• How can we ensure the

interaction between ForCES and the software?

Control Plane (packet flow)

GPP

PCI or Ethernet link

Software Software

Data Plane (packet flow)

NIC NIC

GPP

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Modular router: Click Modular router: Click

• Developed by MIT
• Modular, flexible, extensible and configurable
• Built from packet processing modules called

« Elements ». Click Element

• Software component representing a unit of

router processing

• Interconnected interfaces « connections »

SMP Click

• Provides both flexibility and performance on

multiprocessor platforms

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Our proposed Software router design based on Our proposed Software router design based on the plane separation approach the plane separation approach

PollDevice PollDevice Classifier Classifier Forwarding ToDevice ToDevice

ForCES ForCES Protocol Protocol

Management Plane

Forwarding path configuration manager interface

Routing Signaling

Control Plane

API Services

SMP Click IP packet processing

Forwarding plane

LFB LFB LFB LFB CE CE

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Dynamic adaptation of edge routers Dynamic adaptation of edge routers

VPN Tunnel

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Dynamic decision in the edge router Dynamic decision in the edge router

Scheduler Marker Classifier Meter In-profile traffic Out-of-profile traffic

Traffic

Dynamic decision

(Out-of-profile)

@IP, Port DSCP SLA (Rate)

Monitoring

High Load Low Load Medium Load

Dropping Shaping Accepting Rate Click DiffServ function

Forwarding path configuration manager interface

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Dynamic behavior of an auto Dynamic behavior of an auto-

• configuration edge router

configuration edge router

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Additional delay caused by dynamic Additional delay caused by dynamic configurations configurations

10 20 30 40 50 60 1 2 10 100 1000 Nb of configurations per second Additional Delay (us) 80 Mbits/s 100 Mbits/s 150Mbits/s

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Effect of dynamic configurations Effect of dynamic configurations

• n the Round Trip Time
• n the Round Trip Time

500 550 600 650 700 750 800 850 900 950 1000 1 10 100 1000 Number of re-configurations per second Aggregate throughput (Mbits/sec) 650 660 670 680 690 700 710 RTT ( µs ) TCP throughput Ping Average RTT

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Conclusion Conclusion

• Improvement of the Software based router design to

achieve performance requirement.

• The proposed design is based on:

– Plane separation: ForCES architecture – SMP Click language (Forwarding plane) – Forwarding path configuration manager interface

• The experienced marginal delays and packet losses are a

favorable sign for the use of software based routers using the separation principle and the SMP Click language.

• Larger scalability studies should comfort these findings

and foster the use of these routers.

Thank you ! Thank you !

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Losses versus aggregate rate Losses versus aggregate rate

0,1 0,2 0,3 0,4 0,5 0,6 0,7 0,8 0,9 50 100 150 160 170 180 190 200 Rate (Mbits/s)

% packets loss (x10 -4)