[PATCH 0/3] Enabling IPv6 on Qualcomm MDM9x00 chipsets

[Dan Williams]

On Thu, 2013-11-28 at 14:30 +0100, Bjørn Mork wrote:
> Bjørn Mork <bjorn at mork.no> writes:
> 
> > Given this, I wonder if maybe IPV4V6 should always be configured as the
> > default PDN type in modems? I'm going to test whether that works for
> > both my SIM types.  Why didn't I think of that before?
> 
> Confirmed.  After setting the PDN type of the default profile to IPV4V6,
> I am able to successfully register in the network using either of my SIM
> types.  Note that neither subscription allow *any* IPV4V6 APN to my
> knowledge.  This default type is just used as a signal to the network
> that the modem can support either protocol, allowing the default bearer
> to be either IPv4 or IPv6.

Yeah, that makes sense, and is somewhat confirmed by something Franko
said in a private mail in which we were discussing how Huawei modems
indicate that capability.  The default profile does appear to be how the
modem signals to the network what it's capabilities are for the default
LTE bearer.

> So I guess it's a good idea to always configure a IPV4V6 default
> profile, regardless of the actual requested APN PDN type.  This ensures
> maximum interoperability with the network for modems supporting IPv6, by
> not placing any restrictions on the default bearer.

Though this can be provider specific, unfortunately.  For example,
Verizon (used to?) provision their modems as such:

1: IPV6, vzwims
2: IPV4V6, vzwadmin
3: IPV4V6, vzwinternet

#3 is what is used to actually make a data connection, and there's
various problems with overwriting this APN layout and then trying to use
the device with Verizon's connection software.  Basically, I mean there
my be implications with trying to modify the default APN list, and doing
that would certainly be incompatible with other connection managers that
ISPs might provide?

Dan