Conference Calls

Note: This page refers to Australian Telstra telephones and is probably not relevant to telephone users in other countries.

Introduction

Sometimes it is desirable to have more than two people participating in the same telephone call. Telstra provides two facilities for this:

Telstra Easycall Three Way Conference Calls: Telstra provides a simple three-way conference call facility that anyone can use. Once a two way call is in progress, either participant can conference in a third caller instantly by pressing a few keys on their phone.

Telstra Conferlink Conference Calls: This is a service aimed at businesses. To create a conference call you book it for a specific time. When the time comes, each participant dials in and provides a passnumber for entry into the conference. This facility costs AU$0.60 per minute plus the cost of each call from each participant to the conferencing hub (whose location is chosen by Telstra at the start of the call). As far as I know, there is no practical limit on the number of callers. For more information on this see www.telstra.com.au/conferlink.

These two facilities cater for the two ends of the market, but do not directly address the need for small (e.g. 4 to 6 people) spontaneous conference calls. This document explains how to use the Easycall facility to create a three-person, four-person or N-person conference call.

How To Use Telstra's Standard Three-Way Conference Call Facility

As far as I know, Telstra's three-way conference call facility is available to everyone in Australia with a Telstra landline telephone. I think it costs about 25 cents to invoke (but I'd have to check that). To make conference calls, you need to have a RECALL button on your phone. I don't know how to make such a call if there is no such button on your phone.

Suppose that you are on a phone call to person X and you want to conference in person Y. Here' how to do it:

Ask X to wait.
Hit RECALL.
Dial Y's phone number.
Wait for Y to answer.
Hit RECALL 3.

You and X and Y should now be on the same call and should be able to talk to each other.

If Y does not answer, or you are put through to voicemail or something like that, you can hangup on the connection to Y by hitting RECALL 1. You will then find yourself talking to X again (only).

If it is taking a long time for Y to answer (perhaps an operator has put you on hold), and you want to reassure X to keep waiting, you can switch between X and Y (up until the time to you conference them together) by hitting RECALL 2.

How To Daisy Chain Conference Calls

The Telstra Easycall Conference Call facility provides a very convenient way to conference three people together. Unfortunately, Telstra doesn't explicitly provide a way to conference four people together. However, it can be done by "daisy-chaining" two three-way conference calls together. Here's how to do it.

Suppose that you call X and then conference in Y using Easycall.

   X ----- You ----- Y

At this point, you cannot conference in anyone else (because Telstra's facility has a limit of two). However, X and Y can!. So all that needs to be done to conference in Z is for X or Y to conference in Z:

Either
   Z ----- X ----- You ----- Y
Or
   X ----- You ----- Y ----- Z

A fifth person could (presumably) be conferenced in by having both X and Y conference in another person:

   Z ----- X ----- You ----- Y ----- A

Presumably, people could be added to the ends of this chain indefinitely. In this way, an N-person conference call can be organised without having to use. Telstra's Conferlink facility.

At 1:30pm on 24 July 2003, I performed an experiment to see if I could daisy-chain two Telstra three-way conference calls. It worked and I managed to have four people talking on the same call. Presumably it would work with even more people.

Advantages Of Daisy Chaining

The advantages of daisy chaining conference calls are:

It's cheap: At a one-off 25c conference call setup fee, it's a lot cheaper than the ConferLink facility at 60c/minute.

It can be done instantly: An N-way conference call can be set up instantly without having to book it.

Disadvantages Of Daisy Chaining

The disadvantages of daisy chaining conference calls are:

Participants can't leave: Participants who are not at the end of the chain can't leave the conference call without splitting the chain. (Actually, it may be possible to reconnect the chain using the call-waiting facility).

It's vulnerable to dropouts: If a party's phone loses power or their line is cut by accident and they are not at the end of the chain, the chain will be split.

It would take time to set up a large call: With a booked conference call, you can have as many as 10 or more people joining the call simultaneously. However, with a daisy chained call, each person must be added one at a time (or two at a time if you're clever about it).

You have to explain it to everyone: In order to make a daisy-chained conference call work, everyone in the call (except those at the end of the chain) must understand how to use the Easycall conference call facility. This can be a big ask, and is partly why I created this web page.

Open Questions

Does everyone in Australia with a landline have access to the Telstra Easycall three-way conference call facility?

How much does a standard three-way conference call cost?

Will daisy chaining actually work with more than four people?

How many people can be daisy chained together before audio quality drops to an unacceptable level?

Can call-waiting be used to connect two daisy chains together? If so, it would be possible to assemble two halves of a chain independently and then connect the two chains together by connecting the ends. This would allow long chains to be assembled in parallel. It would also allow broken chains to be reconnected.

Is there a standard way of performing conferencing on mobile phones, or does each mobile phone provide a different interface?

Ross Williams (ross@ross.net)
24 July 2003