[cisco-voip] Can't use Telstralink conferencing service - DTMF tone duration?

[Robert Kulagowski]

Jonathan Charles wrote:
> Okay, change the dtmf-relay from H245 to none and try sending it 
> in-band, however, if you are using a low-bandwidth codec (G.729, etc...) 
> this will distort the DTMF.
> 
> http://www.cisco.com/en/US/products/sw/iosswrel/ps1831/products_command_reference_chapter09186a0080087c0a.html#1021746
> 
> As Scott said, the alternative is to use MGCP, which is pretty adept at 
> transmitting DTMF, but that presumes a CallManager that may or may not 
> be present.
> 
> Also, this is receiving or sending DTMF on the gateway? (IOW, are you 
> sending DTMF out a PRI, or receiving it from a PRI?)
> 
>  What is the config on the voice-port for the PRI?

This is a phone in Sydney sending a call out of a PRI in Sydney.  Would 
G.729 even be an issue in this situation?

I think that we need the dtmf-relay to stay as-is for access to Unity, 
correct?  The over-the-WAN codec is set for G.729.

We can't do MGCP because of call preservation, plus the CMs are in the U.S.

The voice-port is:
voice-port 0/1/0:15
  translation-profile incoming PREFIXDID
  input gain -3
  output attenuation -6
  echo-cancel coverage 24
  echo-cancel erl worst-case 0
  playout-delay minimum low
  no comfort-noise