Re: Connection dropouts
I would suggest an incompatibility of modem chips.
Hundreds of modems are available on the market, all with their own peculiarities and idiosyncrasies. With a dozen or more protocols, modems that have problems supporting exact communications specifications often need special "training" in order to work correctly.
Some modems (particularly those using Rockwell chips) try to connect at too fast a line rate for the prevailing line conditions (“aggressive modems”). This gives rise to excessive transmission errors, they train down or the call is dropped out by the ISP. A connection experiencing lots of errors will result in lots of data block re-transmissions and the data throughput may actually be LESS than if you had connected at a lower line speed. It may be very useful to instruct the modem to connect at a lower maximum speed.
Verify your modem is not an RPI SW Error Correcting Modem
If your modem has an RPI chipset and it is a Class 1 modem, it does not support hardware error correction. Error Correction is the feature in high speed modems that allow it to compensate for changes in line conditions. The modem will actually decrease and increase its connection speed depending on the current line conditions. Hardware error correction is when the modem itself regulates the error correction. Software error correction is where the modem has to rely on the computer processor to perform the error correction. Software error correction can cause long delays which usually ends in a disconnection. Since most services require hardware error correction these RPI modems are unreliable at the very best.
The best way to find out if you have a software error correcting modem is to call your modem manufacturer and ask them if your modem model is software error correcting. If you verify your modem is hardware error correcting you should check for the latest version of error correction.
Verify your Modem has the latest Firmware Updates
Most Hardware Error correcting modems offer Firmware Updates meaning the modem can be upgraded without having to purchase a new modem. There are two different kinds of
Firmware upgrades:
An actual chip is sent from the modem manufacturer to replace the existing chip. This is usually done for a small fee unless there is a known bug with your firmware revision (which is the case most of the time). Make sure you tell them you are having problems.
2. FLASH Upgrades
These are basically software upgrades that are burned into the modem. They are usually free and offered off the Modem Manufacturer's Home Page or BBS.
Firmware updates can sometimes increase your baud rate but most importantly it updates the Error Correction. Error Correction is negotiated during the modem handshake and if the modem has bad Error Correction you may receive Endless Handshaking. Other problems can include frequent disconnections and low connection speeds (note most of time low connect speeds are related to phone lines). Make sure you also obtain your software package help guide and try a different access gateway to verify the problem is not a local problem. Many models of Megahertz, IBM MWave and USR modems are known for needing firmware updates. Contact your manufacturer for details.
56K modems push the phone line to the limit, and need to "retrain" (that means change speed) regularly to keep up with the line conditions. It takes a few seconds to do this retraining, and these are the pauses the user may experience. Sometimes, when the retraining occurs, it can't successfully negotiate a new speed and will hang up. As this problem becomes more pronounced the faster the modem runs, it may be wise to "lock" the modem at a certain speed. First try intermediate speeds such as 44kbps, 40kbps etc. Failing all else, turn off K56Flex in the modem all together and connect with 33.6kbps (V34)
Good Luck.
