why my internet connection fail?

There are many reason subscribers will get failure during access CDMA 1x through the Laptop/PC or handsets. The reason could be from subscribers end or network providers. Which side is having problem during accessing can be identified from the display errors that sent to subscribers. Errors mentioned below are common occurred at CDMA 1x but it is possible that the same errors occurred in the others network platform e.g. GSM, 3G and WCDMA networks
Here are data session processes starting from subscribers until they get internet service. Generally these processes are done by subscribers using Laptop/PC

1. Subscribers preparing their device by connecting the modem device to the Laptop/PC
Subscribers need to make sure that there are no issue connections in their device before data call dialing. It can be done by query the modem attached to the laptop/PC. Once query received succeed messages, it means the device ready to make a session
2. Data call then will request RF channel to the BTS. Once the channel is available then it will be occupied for active subscriber’s session.
Channel will be occupied as long as subscriber is active status. It means once subscribers leave the Laptop/PC and do nothing for a few time until reach dormant time then the session will be terminated
3. BSC will send IP channel to PDSN network
MSC will identify what kind of request send by subscribers. If it data call request then forward it to PDSN to reserve IP channel. MSC identified the called number sent by subscribers and if it is specific number (in this case #777 is a data call request) then MSC will send it to PDSN. At the same time, MSC will identify the subscriber number whether it is authorized to get data cal in the HLR. If the subscriber profile is available in the HLR then he/she will allowed to access it

4. PDSN will process the request and send the traffic once the parameters required is complete

There are many process will be executed by PDSN as the core device to serve data call.
They are:
- Allocating IP Pool: subscribers will be reserved one IP Pool to this session
- Sending authentication request: Authentication server will identify if the subscriber is a valid session. If yes then will be allowed to go to the next step
- Sending accounting request: this is the next step after authentication step is passed. Accounting server will check whether subscriber have enough balance or not. If balance is enough then will be permitted to access the internet service or another services provided by network provider. If not enough then the session will be blocked
- Forwarding internet traffic to customer through BSC's PCF

Below are errors message will be received by subscribers once they got unsuccessfully data call session;
1.Invalid username and password (error 691)
This error due to some reason below:
a. Subscriber put the wrong username and password.
b. Subscriber’s dialer has gone corrupt

How to get this error to go away:
1) Check the username and password.
2) Check which number the dialer is dialing, it should be #777.
3) Recreate the dialer.
Steps to recreate dialer:
a) Go to ‘Start’ >> ‘Control Panel’ >> ‘Network Connections’ >> on the left hand side you have the option ‘Create a New Connection’.
b) Follow the steps as: click on ‘Next’ >> ‘Connect to Internet’ >> ‘Setup Connection Manually’ >> ‘Connect Using Dialup Modem’ >> then enter username and password >> click ‘Finish’.

2.Hardware (modem) problem (error 797)
This error is coming due to modem was installed improperly. How to make sure the modem was installed proper or no?
a)Go to ‘Start’ >> ‘Control Panel’ >> phone and modem option >> click modem >> properties >> diagnostic >> query modem
b)Once this query is getting succeed response message, it means the modem is ready to be used

3.The remote computer did not respond (error 721)
This is error due to many reasons;
a.Session is not getting RF channel from the BTS
b.The number used by subscriber is not registered in the HLR to have data service feature. HLR is checking that the number is not available to have data service feature
c.The session is rejected by HLR
How to get this error to go away?
If this is caused by RF capacity what we can do is trying to connect in the low traffic time. But if this is caused by HLR customer need to contact the provider the check the number