Furuno Felcom 50 Operator's Manual page 129

It is included for information only. However when you are not able to establish
the Dial Up Adapter, the "FURUNO" procedure has been to try the At+Wreg=1 ,
in order to verify whether or not this has been a SBS or RLES problem.
Verifying MPDS with AT-commands
Access to AT-commands
Instead of using the PC hyperterminal facility, access can easily be
accomplished using vtLite Mobile, or using Hyperterminal.
Start vtLite again:
You can now key in at+wreg=1 from vtLite:
REGISTERED : MPDS is operational
FAILED
SBS
COM1
: MPDS is not operational.
Verify that MPDS is available for
your terminal. See function 99,
Customization > Paid functions.
If necessary, check that MPDS
has been commissioned at your
Net Service provider.
6. DATA COMMUNICATION
6-39