The real question remains without a clear answer.
Nokia cell phones with internal phones are able to originate and connect to internet and other modems linked by using DRL-3P cable this are fact.
When trying to receive a data call from another modem and connect with other modem, this is will be a very big problem. When trying to receive a data call I believe that almost users never tried it they will hit with a big problem.
First the modem emulator used, perhaps by using a DSP modem emulator program is unable to answer automatically a FAX or data call.
Fact: Follows the answer received from Nokia customer care.
"We have confirmed with our Technical Support Team the following: The Nokia 7160 phone can make and receive fax calls. However, much like the Nokia 9290 Communicator the Nokia 7160 phone requires a dedicated fax number in order for the software that is present on his PC and the modem emulator in the phone to recognize that the inbound call is in fact a fax call. If the carrier does not offer this service there is not a way to notify the fax software or the phone that the inbound call is indeed a fax."
This answer applies only for fax calls. After ask the same answer about data receiving call, no more answers come from Nokia customer care.
TDMA Nokia modems are Hayes compatible "with small changes"; other GSM phones are GSM 07.07 compliant. Nokia refuses to release a full declaration or document about AT COMMANDS FOR TDMA products. One Hayes compatible modem is able to answer automatically data calls by a simple command "ATSO=n" where n is the number of rings to answer a data call.
I was informed that NONE of the Nokia phones answer data or fax calls automatically. They would not provide me with a written statement. According to them, the absence of the statements in their documentation is enough.
Even with absence of statements "Nokia phones answer data or fax calls", I wonder how to automatically answer phone, and connect with a single "ATA command".
After asking Nokia to receive a data call, I was informed that this is my operator line problem and my operator line problem said that this is a phone problem. Other phones like Motorola V60T and a lot of old ericcson phones does not have this problem. Nokia said that this is not a merit of question; my line operator must be ready to Nokia phones.
After that Nokia proposes-me due to avoid more justice audiences that they are ready to give my money back.
I wonder if anyone in this forum said me or get a real proof that Nokia phone is able to receive a data or Fax call and tell-me what operator has the required Nokia procedures to do that.
At other side, Nokia have changed the it?s production line and I believe that due to required infrared manual procedures this no longer will be a Nokia problem.
RE: What is the real problem to receive data calls with Nokia TDMA cel modems?
I do not see how this question is related to Nokia PC Connectivity SDK. However as a answer to your post, Nokia PC Connectivity SDK 2.1 supports also Nokia 7160 phone and you can use the SDK for application development. If you are using some third party software for making or receiving data calls, questions related to that software should be directed to the software company.
Also for the comment you wrote here, if the network operator does not support fax or data calls you are not able to receive such calls. If fax or data call support is available, network operator might require you to activate such services on your SIM-card as in most countries.