(There’s a caveat I’ll get to later, but at least I have your attention now).

Every so often a customer will ask me to configure a recording of ringback tone as a Response Group’s MOH source. Their argument is that they don’t want their callers to be placed on hold or appear to be stuck in a queue, so they prefer them to be played ringback tone until their call is answered or they abandon.

Complying with this request will put you in breach of a number of clauses in AUSTRALIAN STANDARD AS/CA S002:2010 “Analogue interworking and non-interference requirements for Customer Equipment for connection to the Public Switched Telephone Network “.

The relevant sections are from 5.3.4 “Supervisory Tones” and 5.3.5 “Automatic Operation”.

Clause 5.3.4.1 defines three “Pre-answer supervisory tones”: ringback tone, busy tone, and the lesser-used “number unobtainable” (NU) tone.

Here’s Clause 5.3.5.3.2  verbatim. The bold “shall” is from the standard. (In case you’re not familiar with Australian Standards, clauses that use the words “shall” or “shall not” are mandatory, whereas other terms including “should” are recommendations only).

CE incorporating automatic answering facilities shall acknowledge the answering of incoming calls from the PSTN by—
(a)  the transmission of an appropriately worded stored voice or synthesised voice message; or
(b)  the transmission of one burst of answering tone of 2100 Hz ±15 Hz for a minimum of 2.6 s up to a maximum of 6.0 s, if a calling tone (CNG) as defined in ITU-T Recommendation V.25 [22] has not been received from the originating CE within 2.5 s. The answering tone should be in the range from –7 dBm to –13 dBm; or
(c)  a post-answer tone dissimilar from a PSTN dial tone, PSTN ring tone, busy tone, or NU tone, as described in Appendix A.

Points (a) & (c) are the clinchers here. (a) states you’ll be in the clear if you play a greeting to the caller first, however if you don’t (as the RGS will permit) and you just throw the caller to your ringback MOH, you’re in breach of point (c).

Why’s this a problem?

The whole point of this clause is to mandate we provide a clear, audible indication to the caller that the call has been technically “answered”, and that charging has commenced – and the moment the call arrives at the Response Group your caller is charged for this call.

Sure, many people are on capped landline or mobile plans these days that include a volume of “free” calls, but not everyone. Those with pre-paid mobile plans are usually more sensitive (and exposed) to call charges, and providing a ringback tone post-answer (without “the transmission of a stored voice or synthesised voice message”) is misrepresenting this situation to them. Even my post-paid Telstra mobile plan includes lots of free calls in a month – but I pay through the nose for calls to “toll-free” numbers like the 1800, 13 and 1300 prefixes you’ll often use to reach a Response Group.

A work-around

If your customer wishes to argue the point, I can offer you a work-around: preface your Response Group with a “dummy” Lync user account that has no-one logged into it, but sim-rings to a Team Call group that includes all of the members of the RGS Agent group. The dummy account will then call forward on no-answer to the Response Group where the caller will be GREETED (please), and then queued to the Agents. At least here the ringback tone the caller hears for the first 30s or so will be free, with charging only commencing when they hit the RGS/queue.

I acknowledge there are a couple of shortcomings with this: you have duplicate administration of your agents, needing to maintain the Team Call list as well as the RGS Agent group; and the maximum time Lync will permit you to signal to the Team Call group is 60 seconds before you have to forward to the Response Group. (In Australia the carrier will normally time-out and disconnect an unanswered call between 60 and 90 seconds anyway, so best go for something like 50s to make sure you don’t accidentally lose them).

References

• AUSTRALIAN STANDARD AS/CA S002:2010 Analogue interworking and non-interference requirements for Customer Equipment for connection to the Public Switched Telephone Network.

Revision History

11th October 2021: Updated the download link to AS/CA S002:2010 in ‘References’
20th October 2013: This is the initial publication

– G.