the trunk calling limit issue result in call forwarding fail

in the custom site, U1980 connects to PSTN with PRA trunk. the intra-office phone A registers the call forwarding service to his mobile phone B. the PSTN user calls to intra-office phone A, but mobile does not ring.
U1980 version: V100R001C01SPC900.

none

make a testing as below:
1. use the phone A directly calls to B. B rings.

2. use the internal phone C calls to A, also B rings. so this means A's call forwarding service is ok.

3. use the PSTN phone calls to A, B does not ring. this means only the PSNT call to A through the trunk, then can not transfer to PSTN again. maybe the trunk configuration is something wrong.

4. do the command to check the trunk outgoing call authority:
     
[%eSpace U1910(config)]#show trunkgroup
TKCGroup Info
GroupNo Office Protocol Direction   Restrict BasicOutgoing WithCUS CLIIndex DomainType
------- ------ -------- ----------- -------- ------------- ------- -------- ----------
6096    254    AT0      BiDirection NO       ---           NO      ---      COMMON
6098    254    PRA     BiDirection YES       INTER           NO      ---      COMMON
26      1      PRA      BiDirection YES      INTER/LOCAL   NO      ---     COMMON
6074    253    PRA      BiDirection YES      INTER/LOCAL   NO    ---   COMMON
TrunkLevel
----------
Default

we can see as for the GroupNo 6098, it is PRA protocol with only INTER outgoing call authority. this means the call from pra to u1980 can not transfer to PSTN by the PRA trunk again.

5. modify the PRA trunk outgoing call authority for example:

[%eSpace U1910(config)]#config modify trunkgroup no 6098  restrict yes outgoingright inter&local&ddd
[%eSpace U1910(config)]#show trunkgroup
GroupNo Office Protocol Direction   Restrict BasicOutgoing   WithCUS CLIIndex DomainType
------- ------ -------- ----------- -------- --------------- ------- -------- ----------
6096    254    AT0    BiDirection YES      NO      NO      ---      COMMON
6098    254    PRA    BiDirection YES     INTER/LOCAL/DDD NO      ---      COMMON
26      1      PRA      BiDirection YES      INTER/LOCAL     NO      ---   COMMON
6074    253    PRA      BiDirection YES      INTER/LOCAL    NO   ---    COMMON
TrunkLevel
----------
====  Command executed success !  ====

6. repeat the testing, ok.

7. save the current configuration.

as above.

as above