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Connection problems or slow connects when dialing a 28.8 or 33.6 modem

If you have a 56K modem but you're dialing into a V.34 modem bank,your modem will still try to negotiate a 56K connection, even though it's impossible. You may want to use one of the commands below to tell the modem to not attempt a 56K connection.


How can I enable or disable K56flex and/or V.90?

The command depends on whether you have a Rockwell-based or Lucent-based modem.

Rockwell chipset modems

For Rockwell-based K56flex modems that do not also support V.90, add +MS=11,1 to the end of your modem init string.

For K56flex modems that have been upgraded to V.90, or that support V.90 and K56flex simultaneously, use these commands at the end of your modem init string:

For most Rockwell chips (except on PCI card modems): Disable V.90 and K56flex, use V.34 (28.8/33.6) +MS=11,1

For Rockwell HCF chips (used on PCI card models):
Disable V.90 and K56flex, use V.34
(28.8/33.6) +MS=V34

For Lucent-based K56flex modems that do not also support V.90, add S38=0 to the end of your modem init string.

For Lucent-based modems that do support V.90, use one of the following strings.

For Apollo (LT Win Modem) and Mars (LT PCI Win Modem) chipsets:

Disable V.90:

        -V90=0

Disable K56flex:

        S38=0

For Venus chipsets (mostly used in external modems):

Disable K56flex and V.90 (use V.34):

        S38=0