Contiguous timeslots on QSIG line

Owned by Nathaniel Halbrooks
Dec 20, 2023
1 min read

Issue

By default, when using the QSIG protocol, bearer channel time slots on Dialogic® DM3 and JCT Boards are numbered from 1 to 15 and 17 to 31, with Channel 16 is reserved for signaling. However, some QSIG PBXs use a 'logical' mapping, which ignores the signaling channel and thus expects B channels 1-30. This can cause problems, as DM3/JCT boards’ QSIG stacks will reject any calls with the channel identification information element set to 16, as they assume that channel 16 is reserved for signaling data. In response, you can specify that the bearer channel time slots on the DM3 and JCT boards use a sequentially-ordered logical channel numbering scheme, from 1 to 30.

Solution

For Dialogic JCT boards

Modify the QNT.prm (Network Side) or QTE.prm (User Side) file:  

;--- ISDN feature list extension ;--- this parameter uses bit masks ; ;--- 01H = not used ;--- 02H = SINGAPORE SWITCH, disable SETUP_ACK, directly send CALL_PROCEEDING ;--- 04H = Send first response from Firmware in case of HOST controlled CALL_PROCEEDING ; using cc_CallAck() for CTR4 only. ;--- 08H = Enable logical channel mapping (1-30), valid for QSIG protocols only ;--- 10H = not used ;--- 20H = not used ;--- 40H = not used ;--- 80H = not used ; ;--- The default value is 00H. ;0029 00

 such to setting 0029 08 will enable logical channel mapping.

Then select this prm file in DCM on the Misc tab of the board.

Product List 

Dialogic JCT E1 boards

 

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