Qualcomm NV documentation (specifically, 'qp_ims_reg_config_db')?

[NathanA]

Many Qualcomm modem NV items are self-documenting, but just as many are not. Is there any documentation that exists for any of the non-obvious ones?

Right now, I'm specifically looking for NV 71527 (ims/qp_ims_reg_config_db). Each ims_rat_apn_info[#] struct member seems to be a bitfield of some sort, but I have no idea what the valid values are.

I managed to find a brief high-level description of the purpose of the NV over here: https://www.it619.net/index.php?doc-view-2687.html

...however, it does not explain what the valid values are, other than giving one example (apparently iRAT == 16 matches against a RAT of LTE, so I assume this means bit 5 of iRAT means "LTE"; what do the other bits mean?).

It also does not explain how each ims_rat_apn_info array element maps to a particular data profile/PDN. There are 10 possible entries (0-9), and from what I've seen, usually the 0 and 9 ones are at least populated. Why #9?

Thanks for any leads, hints, or docs, official or unofficial!!

[carver]

I dont quite understand what it is about,
but try to find the pdf
80-NL507-1 IMS Policy Manager NV Settings Overview

maybe you will find this document on xda,
it has a topic with leaked documentation,
but I couldn't download it.
so can't confirm.

I also recommend QDART, I haven't seen new versions for a long time.
but your NV starting using before 2014.

I don't offer any PDF or EXE. just wrote my thoughts.

[NathanA]

try to find the pdf
80-NL507-1 IMS Policy Manager NV Settings Overview

maybe you will find this document on xda,
it has a topic with leaked documentation,
but I couldn't download it.
so can't confirm.

Thanks for the lead! Unfortunately, "80-NL507-1", "NL507", and "IMS Policy Manager" return no results when searching XDA, and in Google return no useful results. So it's good to know that this document exists, but I cannot find it referenced anywhere!

Did you actually see an XDA post where it was referenced? If so, can you link to it?

Many thanks again!

EDIT: I think I may have found the XDA thread you refer to...1856327? I also cannot access it, which is strange since I am a senior member over there with 8-year-old account. Maybe it was blocked for legal reasons.

[macro]

42864
Hope, it is help you in your search

[carver]

42864
Hope, it is help you in your search

oh, it's just a file from an old QXDM (in notes written that from 2012).
and these files don't describe the nv items structure.

maybe this file from QXDM_v3.

at my laptop it stored:
C:\Users\All Users\Documents\Qualcomm\QXDM\Vendor\Qualcomm\
01.06.17│790653│RA │NVItem.txt
C:\Users\Public\Documents\Qualcomm\QXDM\Vendor\Qualcomm\
01.06.17│790653│RA │NVItem.txt

[macro]

Sory, only tried to help, search and find this file on XDA forum, also there is link on it inside the file

[carver]

I apologize too.

i just use NVItem.txt for many years,
when I need to see nv_item's in modem.

manufacturer nv_items will be without names ))

[NathanA]

QXDM does not seem to know the structure of these particular items. For some items where it understands available options, it will give you a drop down menu to pick fro, but not for these. I think the only way that we will be able to gain knowledge of the meaning of the bitfields is through external documentation.

I did recently discover that for iRAT value, 256 (bit 9) is IWLAN. Previous web site I linked to explained 16 (bit 5) is LTE. So decimal 272 matches against both LTE and IWLAN (for Wi-Fi Calling / ePDG).

I have seen iRAT set in some phones with other bits flipped on. I am guessing that remaining bits must stand for certain kinds of 3G networks (UMTS, 1xEVDO, etc.)?

Still completely unclear what the various other values mean, and what each array index is mapped to. I can make IMS registration work over both LTE and Wi-Fi by only configuring ims_rat_apn_info[0]. So what are the others for? And is there something special about the last one, [9]? Maybe reserved for emergency services?

[carver]

i cleared the qcom watermark and sent you the document link in PM.

yes, qualcomm prohibits the distribution of these documents,
and sometimes sends abuse warnings to hoster.

42876

[NathanA]

Wow, amazing, thank you!!

Document looks like it was rushed to publication, and is not comprehensive / is missing some information (e.g., does not discuss possible values for iAllowedIMSSrvOnWLAN, does not explain usage of bit 5 for iIPTypeInfo, & many others) and contains several typos, but is still very helpful. With this + some trial and error, I think I will finally be able to make MMS APN bearer come up over ePDG connection as well!