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RivuS

Stream Control Transmission Protocol(SCTP) on BSD

By-Jayesh Rane

Nitin Kumbhar

Kedar Sovani

PICT.

Guides: Prof. Rajesh B. Ingle, PICT.

Mr. Adityashankar Kini,

Calsoft Pvt.Ltd.

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RivuS Goals

Implementation of the entire SCTP protocol

in the network stack of 4.3 FreeBSD.

Implementation of Load Sharing extension

to SCTP for Performance gains.

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What is SCTP?

SCTP is Stream Control Transmission

Protocol, a Transport layer protocol.

SCTP is reliable data transfer protocol

which operates over the Network layer

protocol like IP.

UDPIP

PhysicalTCP SCTPApplications

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Why FreeBSD?

FreeBSD is Open source, freely available

Operating System.

FreeBSD is the most well documented,

structured and secure OS.

FreeBSD has maximum number of

Licenses available.

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RivuS Applications

SCTP is general purpose Transport layer

protocol, so it is used in all applications

which run on normal TCP giving moreremarkable advantages like Availability,

Security, Performance gains.

RivuSLoad Sharing, is useful for all theData intensive applications, Real Time

Video Audio server applications.

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Advantages of SCTP over TCP

No Head of line Blocking

Resistance to Denial of Service Attacks

Support for Multi-Homing

Message-Oriented Nature

Partial Ordered Data Transfer

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Head of line blocking

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Features of SCTP

Multi-Streaming

Multi-Homing

Four-way Handshake Association Initialization Chunk Bundling

Partial Order Delivery of data

Packet Validation Path & Peer Monitoring

Shutdown Feature

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Multi-Streaming

different streams within one SCTP

association.

sequence of messages maintained per

stream, which reduces unnecessary head-of-

line blocking.

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Multi-Homing

Multihomed nodes are the nodes which can

be reached under several IP addresses.

Network level fault tolerance

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Association Initialization

Endpoint A Endpoint Z

Create TCB

Generate INIT

Start T1-init timer Create temp. TCB

Create cookie

Send INIT ACK

Delete temp. TCB

Stop T1-init timer

Send COOKIE ECHO

Start T1-cookie timer accept valid cookiesend COOKIE ACK

Create TCB

Stop T1-cookie timer

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Chunk Bundling

SCTP Packet Format

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Shutdown Procedure

Endpoint A Endpoint Z

Send SHUTDOWN

Start shutdown timer

Send SHUTDOWN ACK

Start shutdown timer

Stop shutdown timer

Send SHUTDOWN COMPLETEDelete TCB

Stop shutdown timer

Delete TCB

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Streaming Context

Web Server

over SCTPWeb Client

Request for HTTP

Streaming Objects

Loss/Latency Feedback

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RivuSLoad Sharing

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Load Sharing

Exploiting Multihoming feature of SCTP to

gain performance, increase scalability,

availability and provide user transparency. Performance figures show that we gain very

high performance in data intensive transfers

using our concept of multiplexing data on todifferent paths.

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Load Sharing Concept

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Load Sharing Design

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Gain in performance using

RivuS Since our current

implementation is in

user space, we aregetting 32% gain in

data transfer, after we

put it in the kernel

space, we claim,performance gains of

70% to 80%.

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Other approaches

Ciscos Channel Bonding

Channel bonding is implemented by binding

several Network Interface Cards (NICs) with thesame MAC address. The higher layers of thenetwork stack could be oblivious to the fact thatthe lower level packets were going out (andcoming in) on different NICs.

Sun Microsystems IP Multipathing

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Why RivuS is better than

others? The channel bonding approach is limited to data

link layer and some major hardware changes are

need to be done at both the ends. The IP Multipathing solution is non-portable, I.e.

it works only on Solaris 8.0

RivuS is portable solution with minimal changes

to existing installations and more performance is

achieved.

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Future work on RivuS

Gaining extreme data integrity from data

redundancy between the paths.

RivuS, implementation of SCTP protocol stack onBSD is the first implementation, other

implementation by Cisco Inc. is UDP style, it

doesnt support Connection oriented nature which

SCTP protocol should support inherently. So wehave to get our implementation approved by IETF

group.

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RivuS

Thank You !!!

Jayesh RaneNitin Kumbhar

Kedar Sovani

Visit us:

http://rivus.sourceforge.net/