[VoiceOps] IAM callername instead of CNAM

David Birnbaum davidb at pins.net
Wed Feb 3 12:34:19 EST 2010

That's a mistake/misconfiguration.  I believe Canada sends CNAME inband, but in 
the US, it probably just means somebody is using a client-profile PRI for a 
carrier circuit, doing toll-bypass, or playing other games.  We have seen this 
type of misconfiguration on smaller VoIP carriers.

Time Warner may carry CNAM internal on their network so they can save the money 
on CNAM dips, but obviously that won't go far.




On Wed, 3 Feb 2010, Carlos Alvarez wrote:

> Time Warner does transmit the name info that you send.  We have a TWTC PRI 
> and I've seen the same thing when calling another number on their network. 
> It has even happened to numbers on other networks, though now I can't 
> remember which ones.  One of their engineers confirmed that they do this on 
> purpose, but also couldn't tell me which other networks accept this from 
> them.
> On 2/3/10 9:24 AM, milosz wrote:
>> hi all,
>> has anyone heard of a US residential carrier transmitting the callername
>> parameter from the IAM instead of doing a normal CNAM lookup?  i have
>> some users--for whom the pbx is (intentionally) set up to transmit an
>> invalid cpn--who are claiming that when they call their home phones from
>> the office, their internal (sip) caller name appears on the caller id
>> along with the invalid cpn, which makes no sense from a CNAM lookup
>> standpoint.  the only thing i could think of (other than they are
>> nuts/lying) is that their gateway is transmitting the sip callername in
>> the IAM and the carrier is passing that along instead of doing a lookup.
>>   the btn is the same for all users so that can be ruled out.
>> they are all on cablevision or time warner.
>> thanks,
>> milosz
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> -- 
> Carlos Alvarez
> TelEvolve
> 602-889-3003
> Advanced phone services simplified
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