TOPEX BYTTON HSDPA
User’s Manual
pag. 41
Modem settings:
This section controls the parameters of the Point-to-Point Protocol for the serial connection, in this case
the embedded HSDPA modem. You need to change these settings when you go to a region with
different settings, if you use a different network operator or when you replace the embedded HSDPA
modem with another, external 3G modem that requires special parameters.
AT Init Command #1, 2, 3
: Enter the character strings for the AT commands used to initialize the
modem. Depending on the specifications of your 3G provider, you may need only one AT command or
several.
AT Dial Command
: Dial String, the AT command used to dial to the ISP, which includes the mobile
phone number to be dialed. There are five “At Dial Command” fields. If there is no need to use all of
them, fill the remaining with “AT”. You should not leave empty fields in this section!
Connection settings
Parameters for the connection to the mobile Internet provider.
Authentication –
allows you to select the method of authentication -
you may leave it to Default, or force either PAP or CHAP.
Default
means it will authenticate upon request from the server, it accepts both PAP and CHAP, while
PAP
means it will accept only PAP (password authentication), refusing CHAP, and
CHAP
means it will accept CHAP (challenge authentication) and refuse PAP.
Username
: The user name used for log-in to the 3G (UMTS or HDSPA) wireless network.
Password
: The password used for authentication. You should ask your provider for these settings.
Some network operators do not need username and password, log-in is allowed or not based upon
Caller ID.
MTU
: value for the Maximum Transmission Unit. MTU is the largest physical packet size, measured in
bytes that a network can transmit. Messages larger than this will be fragmented into several packets. The
MTUs should be the size of the reassembly buffer of the receiver, since you try to avoid fragmentation
Different networks have different values for MTU, which is set by the network administrator. The default
MTU size is 576 for many PPP connections, 1500 for Ethernet networks, etc.
Idle Time
: BYTTON can disable the dial-up connection when there is no more data traffic. If no data
packet is sent through the 3G link, the Internet connection will be broken. You can specify this time
interval, in seconds. If you set the time interval to 0 (zero), the dial-up connection will remain always on,
even if there is no data traffic on the remote interface.
When it detects outgoing data traffic, BYTTON automatically performs dial-up, in order to connect to the
Internet.
Route:
Default route
: Disabled or Enabled. This new feature, allows you to ask the Internet provider for a static
address. Usually, the ISP assigns you the first available address each time you connect. Now you have
the options either to accept the dynamic address assigned by DHCP or to ask for a specific static
address. In this case you must fill the other parameters as well:
IP Address
,
Gateway
, and the
Name servers
(primary and secondary) to be used.
