Error 603 - Call Buffer is too small
Solution
  1. Go into control panel > modems > modem properties
  2. Check port speed is set not too low.
  3. open port settings > Check FIFO settings and not set low.
  4. If that did not solve the problem try the following - Note check customer has Operating System CD.
  5. Go into control panel > networks > remove components.
  6. Restart computer
  7. Go into control panel > networks > re-install dial up adapter & TCP/IP
  8. Restart computer. Try connecting
  9. If that did not solve the problem > advise customer to speak to vendor.