49
Fig. 4.7
Types of client authentication at connection to the server modem
The iRZ protocol-based authentication is designed for the cases when the ATM client modem or iRZ proto-
col-enabled software, is installed in the dispatching center. The iRZ protocol-based authentication is imple-
mented by the GPRS password or by the login
– GPRS password pair. The right to connect to the server mo-
dem is not provided for each client, but only for one which has a valid GPRS password or the login
– GPRS
password pair (depending on the server modem settings). This means that their values, specified in the settings
of a connected client, must coincide with those specified in the server modem settings.
GPRS password
authentication: if a new client tries to connect to the modem, and there has been no data
or keepalive packets communication with a current client within a minute, operating connection to the current
client is terminated and connection to a new client is established. Operation with the current client continues in
a different way.
Login and GPRS password
authentication: if a new client tries to connect to the modem and its login and
password are valid, the modem establishes operating connection to a new client and terminates the previous
connection. If the login and password do not match, the server modem continues to operate with the previous
client.
IP address authentication is used when the client holds a public static IP address (when renting APN from
the mobile network carrier
– a private static IP address); the clients with other IP addresses fail to operate with
the server modem.
At authentication by
IP address
: An IP address of the connecting client is compared with the IP address set
in the server modem settings. If the address matches, connection to a new client becomes operational and the
previous connection is terminated. If not, the server modem continues its operation with the previous client.
No authentication mechanism
: when the modem is already working with the current client, and a new cli-
ent is trying to connect the modem at the same time, 2 options are possible:
If data has been transmitted within the last minute, operation with the current client proceeds. In this case
connection of a new client is terminated.
If data has not been transmitted within a minute, connection to a current client is terminated, and connec-
tion to a new connected client is established.
