[asterisk-ss7] libss7 CGU / CGUA type funnies

[Charl Barnard]

Hi All,

We've recently discovered something strange running libss7 (r74): seems like
when the switch we're connected to sends us a Circuit Group Unblock message
with type Maintenance oriented, libss7 responds with an acknowlegement for
type Hardware failure oriented, instead of Maintenance, and vice versa when
CGU is received with message type Hardware-please see the following trace:

+---------+---------------------------------------------+-------------------
-----------------+ 
|BITMASK  |ID Name                                      |Comment or Value
| 
+---------+---------------------------------------------+-------------------
-----------------+ 
|5:08:34 PM,851,406  1:E (Rx):15  MTP-L2  MSU  ISUP  CGU  0-XXX-0  2-XXX-0
000-02           | 
|MTP Level 2 (MTP-L2)  MSU (= Message Signal Unit)
| 
|Message Signal Unit
| 
|-0000111 |Backward Sequence Number                     |7
| 
|1------- |Backward Indicator Bit                       |1
| 
|-1100000 |Forward Sequence Number                      |96
| 
|1------- |Forward Indicator Bit                        |1
| 
|--010000 |Length Indicator                             |16
| 
|00------ |Spare                                        |0
| 
|----0101 |Service Indicator                            |ISDN User Part
| 
|--00---- |Sub-Service: Priority                        |Spare/priority 0
(U.S.A. only)      | 
|00------ |Sub-Service: Network Ind                     |International
message               | 
|**b14*** |Destination Point Code                       |0-XXX-0
| 
|**b14*** |Originating Point Code                       |2-XXX-0
| 
|ITU-T WHITE BOOK ISDN User Part (ISUP)  CGU (= Circuit Group Unblocking)
| 
|Circuit Group Unblocking
| 
|0010---- |Signalling Link Selection                    |2
| 
|**b12*** |Circuit Ident Code                           |000-02
| 
|0000---- |Spare                                        |0
| 
|00011001 |Message Type                                 |25
| 
|------00 |Cct grp supervis msg type                    |Maintenance
oriented                | 
|000000-- |Spare                                        |0
| 
|00000001 |Pointer to parameter                         |1
| 
|Range and status
| 
|00000101 |Parameter Length                             |5
| 
|00011101 |Range                                        |29
| 
|**b30*** |Status
|'111111111111110111111111111111'B   | 
|00------ |Filler                                       |0
| 

+---------+---------------------------------------------+-------------------
-----------------+ 
|BITMASK  |ID Name                                      |Comment or Value
| 
+---------+---------------------------------------------+-------------------
-----------------+ 
|5:08:34 PM,925,025  1:F (Rx):15  MTP-L2  MSU  ISUP  CGUA  2-XXX-0  0-XXX-0
000-02          | 
|MTP Level 2 (MTP-L2)  MSU (= Message Signal Unit)
| 
|Message Signal Unit
| 
|-1100000 |Backward Sequence Number                     |96
| 
|1------- |Backward Indicator Bit                       |1
| 
|-0001000 |Forward Sequence Number                      |8
| 
|1------- |Forward Indicator Bit                        |1
| 
|--010000 |Length Indicator                             |16
| 
|00------ |Spare                                        |0
| 
|----0101 |Service Indicator                            |ISDN User Part
| 
|--00---- |Sub-Service: Priority                        |Spare/priority 0
(U.S.A. only)      | 
|00------ |Sub-Service: Network Ind                     |International
message               | 
|**b14*** |Destination Point Code                       |2-XXX-0
| 
|**b14*** |Originating Point Code                       |0-XXX-0
| 
|ITU-T WHITE BOOK ISDN User Part (ISUP)  CGUA (= Circuit Group Unblocking
Ack.)              | 
|Circuit Group Unblocking Ack.
| 
|0000---- |Signalling Link Selection                    |0
| 
|**b12*** |Circuit Ident Code                           |000-02
| 
|0000---- |Spare                                        |0
| 
|00011011 |Message Type                                 |27
| 
|------01 |Cct grp supervis msg type                    |Hardware failure
oriented           | 
|000000-- |Spare                                        |0
| 
|00000001 |Pointer to parameter                         |1
| 
|Range and status
| 
|00000101 |Parameter Length                             |5
| 
|00011101 |Range                                        |29
| 
|**b30*** |Status
|'111111111111110111111111111111'B   | 
|00------ |Filler                                       |0
| 

Any ideas? This obviously leaves the two ends confused about circuit state.

Thanks,

Charl