CFNA - possible reasons why you might activate call divert (and why at that time)? Evidence of activation.

Hi Bugdog, I am just curious if you know that type of network her phone was on at the time there were two type of networks in the US. ANSI-41 network (the older type) and GSM network (This one was just being implemented across the USA in 2005)

The reason I ask is because Cingular had a unique way of how they handled roaming calls while they were switching over.

From their patent

because current GSM networks are not designed to include the ability to indicate to the ANSI-41 network when a call to a wireless telephone goes unanswered or when the wireless telephone is busy, one of two different scenarios are likely to occur: (1) the calling party receives a message indicating the ANSI-41 customer is “out of network,” the ANSI-41 customer receives a message indicating a call was missed, and no mechanism is provided which allows the calling party to access the ANSI-41 customer's voice mail service; or (2) the GSM network, having received the call, forwards the call from the GSM network to the ANSI-41 customer's voice mail service via the ANSI-41 network without indicating status information to the ANSI-41 network.

I found this paragraph which correlates with a flow chart interesting also

Next, MGW 102 constructs and sends a message which includes the temporary transfer-to telephone number to GSM serving MSC 104 (step 208). More particularly, the temporary transfer-to telephone number is populated into both the busy field (“CFB” field) and the no answer field (“CFNA” field) of an INSERT_SUBSCRIBER_DATA message. This message is received at GSM serving MSC 104, which stores the temporary transfer-to telephone number and acknowledges the message (step 210). These steps are indicated at points A and B in FIG. 4. The flowchart ends at the finish block 212. Subscriber unit 106 is now registered and operates in “standby mode”.

http://www.google.com/patents/US6996396

Also do you know if the phone has an option of "no roaming"?

Mind does in my settings, and when I am in an area that I would be charged roaming fee, then my phone will not ring or notify me someone is calling it will directly call forward my call as CFNA. Then when I am no longer roaming it will give me a notification of a message and my call history on my phone shows who called me.

/r/HiveMindMaM Thread