Telephone system CONNECT speeds may be deleterions affected,
if a country code is not properly set.  The premanance of 
such settings on particular modem hardware is not known.

The commmand to change country setting is 
   AT+GCI=b5
for the particular case of the USA. 

While it may NOT be necessary at every dialin,
this could be implemented within a dialup script as:

"" ATZ
OK AT+GCI=b5
OK YourRegularInitString
# OK ATQ0V1E1S0=0&C1&D2S11=55+FCLASS=0   is commonly chosen by wvdial
OK ATDTphone_number_of_your_InternetProvider
  and so forth

The command takes a t.35 country code in hexadecimal.
The list of currently supported t.35 country codes.
The "," are NOT part of the code, which are added 
for those who may SAVE in a format not supporting TAB separators.
If your country is not listed, try to get infornation locally.
Send any update info to: discuss@linmodems.org

The excerpt below suggests that at least for some modem 
firmware/hardware,, a Lucent modem in this particular case, "exercising"
the country code setting may bring benefits in CONNECT speeds.
 From: "Robert D. Arendt" <rda@rincon.com>
   I'm in Arizona, yet the Israel GCI seems to give the repeatable
   good connect rates.  From a cold-start, using the default North
   America setting seems to limit connect rates to 28800.  Changing
   it to GCI=58 increases connect rate.  Changing back to North
   America retains connect rate.  The Dell laptop internal modem
   hardware may not be properly init'd without explicitly setting
   this parameter.  I'm sticking with GCI=58 ...
Note that improper usages of country codes may be illegal in some Host
Countries.


country code  , t.35 hexidecimal code
---------------------------
USA 	 1	, b5
JPN	81	, 00
GBR	44	, b4
DEU 	49	, 42
SWE 	46	, a5
DNK 	45	, 31
FIN 	358	, 3c
NOR 	47	, 82
AUT	43	, 0a
CHE 	41	, a6
RUS 	 7	, b8
AUS 	61	, 09
MYS 	60	, 6c
CHN 	86	, 26
BEL 	32	, 0f
CYP 	357	, 2d
FRA	33	, 3d
GRC	30	, 46
ISL	354	, 52
IRL	353	, 57
ISR	972	, 58
ITA	39	, 59
LIE	423	, 68
LUX 	352	, 69
NLD 	31	, 7b
PRT	351	, 8b
ESP	34	, a0