gsm muxing and GPRS: am i missing something?

[Tom Yates]

i've pretty much got this working under 2008.08, following various wiki 
and other writeups, for which many thanks to the authors.

my writeup's at http://www.teaparty.net/technotes/openmoko-2.html#GPRS , 
if anyone's interested; i went for "with GSM multiplexing but without a 
GUI".

i can make a GPRS connection.  when it's up, i can place a call, and the 
outgoing GPRS connection temporarily suspends.  when it's up, incoming 
calls go straight to voicemail; the phone doesn't even give me the choice 
of accepting the call.

my understanding from the wiki was that "GSM multiplexing allows both a 
GPRS connection and a phone call to be handled at the same time".  so i'd 
sort of assumed that i could still take an incoming call, even if that 
would temporarily suspend the GPRS connection.

so: have i misunderstood completely?  is the MUXing simply about sharing 
access to the modem, rather than the "line" (ie, connection between modem 
and network) as well?  or should i be able to take an incoming call while 
the GPRS is up?  and if so, should the GPRS suspend while i do, or should 
i be able to run them both simultaneously?

before i start trying to find out *how* to configure pppd to do what i 
want, i'd like to know if the phone is capable of it!  i'd very much 
appreciate any ideas or insights anyone has on this.


-- 

       Tom Yates  -  http://www.teaparty.net