Thursday, October 12, 2006

Historty of VoIP

Pre VoIP Project history

The project first started with evaluation of Voice over ATM because at that stage VoATM was available as well as standards, and vendors did not have available VoIP products.

The VoATM started with using ATM to provide a dedicated Permanent Virtual Circuit (PVC) data pipe between two PABXs, nothing more sophisticated than glorified Time Division Multiplexing. A report was completed for this part of the project.


The next step would have been to look at ATM switched virtual circuits (SVC) but Jonathan Potter of CSIRO supported and resourced a move to the emerging VoIP technology. A significant driver for this was the fact that ATM was not ubiquitous (did not extend to all locations) and was not likely to do so, but IP did have full reach and thus large potential.


Phase 1 of the VoIP project: early 1998 to 1 October 1999

This phase was to get the VoIP technology working and to test it in a large
pilot between PABXs. During this phase Cisco
provided significant support which was to the mutual benefit of Cisco, CSIRO
and AARNet. This phase was completed on 1 October 1999.

Key successes of this phase:

  • VoIP from PABX to PABX became fully functional, as indicated by the testing and major pilot implementations.
  • The VoIP technology acted as a fully transparent ISDN or Q.Sig network to the PABXs. The Q.Sig included all the advanced PABX features including Call Back, Centralised Operator, Message Waiting indicator, Calling Name Display as well as Calling Number Display.
  • During the initial setup of a voice call the originating PABX was triggered to route the call to the Public Switched Telephone Network (PSTN) if a problem was encountered in the data network while setting up the call, without either of the users being aware.
  • A light weight Network Management program was written to stop VoIP during outages, usually on microwave links.
  • The voice quality was near toll quality.
  • Facsimile traffic was supported up to 14,400 bits per second, i.e. up to ITU G.3.
  • A Billing S*ystem was written that invoiced the caller and generated
    MIS reports.
  • CSIRO had seven Gateways that connected PABXs into the AARNet Voice Service. All Long Distance telephone traffic from CSIRO sites to the major capital cities (not Hobart or Darwin) was sent via AARNet. Calls to the local call area hopped out of AARNet into a CSIRO PABX, which then completed the call by making a Local call into the PSTN.
  • CSIRO was averaging 3,500 calls per working day with an average call duration of 237 seconds per call, with a 90% saving on call charges (60% of CSIRO calls were between CSIRO sites and thus did not include the Local call charges). Other AARNet Members were likely to achieve savings of 70% to 80%.
  • Gatekeepers worked and vastly simplified routing tables.


    Key caveats of Phase 1:

  • Past generation Video Conference equipment that relied on clear 64kbps ISDN channels WAS NOT SUPPORTED. However the H.323 VoIP technology, which was initially designed to support video, would enable advanced video technology using IP.
  • Modem traffic WAS NOT SUPPORTED, and was not likely to be in the future.




Phase 2 of the VoIP Project: 1 October 1999 to 2001

This phase was to roll the technology out to all the AARNet Members and to install Gateways where it was cost effective to do so, that is, there was enough traffic to the local area to warrant the installation of a Gateway. This phase had several parallel components:

  • Installed Gateways to allow Member telephone traffic to hop out of the AARNet Voice Service at key areas. Initially they were in Canberra, Sydney, Brisbane, Perth, Adelaide and Melbourne.


  • Selected a Carrier to carry the Local call from the above Gateways into the Public Switch Telephone Network (Last one installed October 2000). Public information about the Tender is available.


  • Wrote and deployed a Network Monitoring Application AARNet call VoIPMonitor that was scalable to a network the size of AARNet and stopped VoIP over links that were failing.
  • Assisted AARNet Members to connect to the AARNet Voice Service.



A loose status of the installation of VoIP at each member institution was maintained.

This phase of the project suffered a massive delay while negotiating a contract with the Carrier for the ISDN connections to connect the AARNet Gateway back into the PSTN (several months). There was also an average 124 day delay waiting for installation (some 3.5 months late).



Phase 3 On-going operation

This phase is the ongoing operational component of the project and includes:

  • support; and
  • dimensioning the network to carry the traffic

Projects that may begin where this project ends are:

  • Video over IP;
  • User directory services for global roaming; and
  • User Authentication and Authorisation for roaming Voice and Video over IP.






posted by ch0yaks @ 10:04 PM

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