Nandu,
No we do not hve a serial connection for message waiting, it is all done on the Qsig link to the Cycos MRS. Here are the route parameters we are using.
<ROCAP:ROU=100;
ROUTE CATEGORY DATA
ROU SEL TRM SERV NODG DIST DISL TRAF SIG BCAP
100 711002500000001 5 3110000011 0 30 128 01151515 111111000031 001100
END
<RODAP:ROU=100;
ROUTE DATA
ROU TYPE VARC VARI VARO FILTER
100 SL60 H'00000310 H'15460002 H'06300000 NO
END
<RODDP

EST=64;
EXTERNAL DESTINATION ROUTE DATA
DEST DRN ROU CHO CUST ADC TRC SRT NUMACK PRE
64 100 160610000000025000600000 0 1 0
END
<RODDP

EST=90;
EXTERNAL DESTINATION ROUTE DATA
DEST DRN ROU CHO CUST ADC TRC SRT NUMACK PRE
90 100 160610000000025000600000 0 1 0
END
<ICMWP:SID=10;
INFORMATION COMPUTER MESSAGE WAITING DATA
SID DTXT KFCN DIG
10 B5BSB10B MWC 9000
END
<ASPAP

ARNUM=88;
APPLICATION SYSTEM PARAMETERS
PARNUM PARVAL
88 1
END
<
The Message waiting parameter on Cycos MRS should be MWI/nnnn where nnnn is the extension number.