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Reliability of ISDN for data transmission

Reliability of ISDN for data transmission

Reliability of ISDN for data transmission

fixnet (TechnicalUser) Dec 5, 2004

I am a new member and am currently using ISDN for three computers and a voice line. I have the basic line with two channels. The channels are bound and the modem is accessed thru a LAN.

This is my first experience with ISDN. It is the most economical choice I have.

I am using a Ascend Modem Model # P751URB1. The program used to program it is a Pipeline Hyperlink. The computers are running Windows XP and Windows 2000.

The problem is the reliability of the connection. Sometimes it connects right up to the internet and then it will suddenly be unable to find the connection. I have found no reliable solution for this.

Sometimes it seems to restore the connection if I disable and then enable the LAN and sometimes not. All of the setting have been checked and the ISDN line has been verified as good by SBC.

Any ideas?


RE: Reliability of ISDN for data transmission

You'll need to look and see what diagnostics are available from the Ascend. There could be problems at the following areas and there should be diagnostics to help you at least narrow it down. Once you narrow it down that will guide further troubleshooting

Layer 1 - Is there a problem with the ISDN line itself.  Unless you know for sure how SBC tested it, and for how long you can't take their word as fact.

If your Terminal Adaptor (TA) has two POTS ports try dialing from one port to the other and leave it up for half and hour and see if the connection stays up and seems to be working. You can also dial to time and weather and listen for a while and see if you hear dropouts or other problems

Layer 3 - We know there is no main incompatibility here or you could not dial at once. However at Layer 3 you'll be able to tell if the call(s) is/are ebing dropped. If so see if the Ascend allows you to examine the Cause code. Not only should the cause code give some indication, but if you can getr the first octet value it will tell you what portion of the network dropped the call and issued the cause code.

Layer 4 - There may be some problem with the higher level LAN protocols.

I hope this gets you started.

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