This is the third place I have been told to ask this question as both the normal phone and chat support have been unable to answer my question in full.
Here is the issue:
I am a research assistant at Cleveland State University and I am trying to set up a mock VoLTE (yes a mock cellular LTE) network using the following equipment:
- An iPhone 6 Plus running the most recent version of iOS.
- An Agilent E6621A PXT Wireless Communications Test Set (company now known as Keysight)
- Agilent's E6966A SIP Server Software (Provides the Management Entity for the VoLTE)
And this is what is happening:
- The iPhone is able to connect to the mock network just fine. For example, I would be able to stream a YouTube video using mobile data on the iPhone using only the mock network. In other words, it follows the steps of a VoLTE setup, up until the next step:
- The iPhone sends out a SIP "REGISTER" message that contains a "sec-agree" header to the SIP Server Software
- The SIP software rejects the REGISTER request since there is no "sec-agree" requirement to match on the SIP Server Software since the parameters of the sec-header are not known in order to be put into the SIP Server Software.
- Step 2 and 3 repeat till a timer value it is met.
Settings on the iPhone:
- Data usage set to Data and Voice (aka, the VoLTE setting)
- Roaming Enabled
- Internet APN set to "ims" (could this be the problem?)
- All other fields blank
- Wifi disabled at time of connection
Any help, whether from an Apple Engineer or fellow developer is much appreciated.
By helping me, you will allow for research that will create a more secure mobile network for the future by helping uncover the vulnerabilities of existing networks. Thank you!
Side-note: VoLTE is NOT the same thing as VoIP. VoIP uses a different set of protocols. Please don't get the 2 confused when responding.
