Following the procedure you suggested is not working. The Soft Switch is not Mera, its Quintum Soft Switch.
Please check my configuration and the step you suggested. Let me know if anything needs to be change or add.
1. set the pstn trunk group passthru to No.
2. set the forcediprouting number in PSTNTG to 88028821331.
3. Make sure you have the correct disconnect supervision set on the pstntg.
4. create a static route (config be sroute 1) to the Mera and add the dn of 88028821331 to it.
PSTN Trunk Group: 1
Name = PstnPassThrough1
Pass Through = no(0)
PT Trunk ID = 0
Provide Call Progress Tone = no(0)
Busyout = no(0)
Hunt Algorithm = ascending-round-robin(2)
Modem Calls = No(0)
Direction = both(2)
DN Used = public
End Of Dial = yes(1)
End Of Dial Digit = #
Add End of Dial Digit = no(0)
Ivr Type = None
CID = From Interface(0)
External Routing Request = no(0)
Auto Switch Enable = no(0)
Forced IP Routing # = 88028821331
Forced IP Routing # Type = public
Trunk ID(Account Code) = none
Trunk ID Delivery = none
2 Stage Dial = No
Translate Inbound Caller ID = no(0)
Relay Caller ID = yes(1)
IP Extension = no(0)
Maximum LAM Calls Allowed = 8
LAM: Index Pattern Replacement NumberType
Cas Signaling Type = loop start(1)
Cas Orientation = user(0)
Dial Tone Detect = yes(1)
Dial Delay Timeout = 1000
Answer Delay Timeout = 60
Flash-Hook Signaling = no(0)
Supervision = answer and disconnect(3)
Caller Id Detection = no(0)
dtmf-ontime = 100
dtmf-offtime = 100
unit# 1 line# 2: 1
Static Route #1
RouteName = roaming
Gkmode = Destination is a Gateway (0)
CallSignalAddress = xxx.xxx.xxx.xxx:1720
1:88028821331 Public LAM priority(255)