the first implementation of rtp framing for e-vlbi

The First Implementation of RTP Framing for e-VLBI What e-VLBI needs: Efficient transport mechanism Standard protocols Internet-friendly transport Scalable Implementation Ability to multicast Acronym Guide: RTP: Real-time Transport Protocol VLBI: Very-Long-Baseline Interferometry RTCP: RTP Control Protocol UDP: User Datagram Protocol RTP provides a standard format for: Transmission of sampled analog data Dissemination of session information Monitoring of network performance Adaptation to varying network Appropriate reliability/ repair model Multi-cast distribution of statistics Past problems: Traditionally, VLBI data is stored on tapes/disks and shipped to a central location for processing, but results could take weeks due to shipping. FTP has been used but it was not designed for high bandwidth or long distances. With telescopes all over the world how does the data get to a correlator for processing? Fact: The average usage of networks like Internet2’s high speed Abilene network is less than 20% in the long term. However, e-VLBI can take advantage of this currently unused network! Other advantages of e- VLBI: Faster turnaround of results Higher sensitivity Lower costs Quick diagnostics and tests What is the best way to ship data over long distances quickly? RTP framing works!! RTCP in conjunction with RTP provides: Mechanisms for reliably monitoring a networks’ real- time data delivery performance Means to collect statistics from participants and distribute them to other participants Ways to adapt transmission strategies to prevailing network conditions Fact: Uncontrolled high-bandwidth UDP Flows can affect other network users’ traffic For this reason, e-VLBI uses control protocol to become a transparent user Experiment ran July 15, 2003 The future of e-VLBI Many telescopes will be able to send date to many correlators Data will not need to be stored of disks Protocols developed can be used in other fields, outside e-VLBI Amanda Morrow [email protected] .edu David Lapsley [email protected]. edu Alan Whitney [email protected]. edu

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Amanda Morrow [email protected]. David Lapsley [email protected]. Alan Whitney [email protected]. Past problems: Traditionally, VLBI data is stored on tapes/disks and shipped to a central location for processing, but results could take weeks due to shipping. - PowerPoint PPT Presentation

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The First Implementation of RTP Framing for e-VLBI

What e-VLBI needs:Efficient transport mechanismStandard protocolsInternet-friendly transportScalable ImplementationAbility to multicast

Acronym Guide:

RTP: Real-time Transport Protocol

VLBI: Very-Long-Baseline Interferometry

RTCP: RTP Control Protocol

UDP: User Datagram Protocol

RTP provides a standard format for:Transmission of sampled analog dataDissemination of session informationMonitoring of network performanceAdaptation to varying networkAppropriate reliability/ repair modelMulti-cast distribution of statistics

Past problems:

Traditionally, VLBI data is stored on tapes/disks and shipped to a central location for processing, but results could take weeks due to shipping.

FTP has been used but it was not designed for high bandwidth or long distances.

With telescopes all over the world how does the data get to a correlator for processing?

Fact:The average usage of networks

like Internet2’s high speed Abilene network is less than 20% in the long term.

However, e-VLBI can take

advantage of this currently

unused network!

Other advantages of e-VLBI:Faster turnaround of resultsHigher sensitivityLower costsQuick diagnostics and tests

What is the best way to ship data over long distances quickly?

RTP framing works!!

RTCP in conjunction with RTP provides:Mechanisms for reliably monitoring a networks’ real-time data delivery performanceMeans to collect statistics from participants and distribute them to other participantsWays to adapt transmission strategies to prevailing network conditions

Fact:Uncontrolled high-bandwidth UDP

Flows can affect other network users’ traffic

For this reason, e-VLBI uses control protocol to become a

transparent user

Experiment ran July 15, 2003

The future of e-VLBIMany telescopes will be able to send

date to many correlatorsData will not need to be stored of disksProtocols developed can be used in

other fields, outside e-VLBI

Amanda [email protected]

David [email protected]

Alan [email protected]

(Spectral Line) VLBI