One way sound/only ringing

[martinnystrom]

Hello, "ONE" extension are noticing that some numbers who reach the extension come with no sound. For the person who makes the call it does only ring and ring. And for the extension who picks up the call it's silent. Seem's like the IPO does not reckon that the extension has picked up the phone. It does only seem to apply to some numbers, for an example this "dummy" number 4670XXXXXXX rang three times within 5 minutes, same issue for all of them while others made it through just fine.

Direct Media Path has been played with, no change.

Here is a trace of the call:

Line: type=Q931Line 13 Call: lid=13 id=19 in=1
Called[026XXXXXX] Type=National (2) Reason=CMDRdirect SndComp Calling[073XXXXXXXX] Type=National Plan=ISDN Pres=Allowed (0)
BC: CMTC=Speech CMTM=Circuit CMTR=64 CMST=Default CMU1=ALaw
BChan: slot=0 chan=4
1536086608mS PRN: Q931Trunk: Found QBChannel to match 0.4 --> 7.5
1536086608mS CMCallEvt: 0.718661.0 -1 BaseEP: NEW CMEndpoint f4efd188 TOTAL NOW=4 CALL_LIST=1
1536086608mS CMCallEvt: CREATE CALL:240225 (f4e3a484)
1536086609mS CMCallEvt: 0.718662.0 -1 BaseEP: NEW CMEndpoint f4dfbd80 TOTAL NOW=5 CALL_LIST=1
1536086610mS CD: CALL: 13.19.1 BState=Idle Cut=1 Music=0.0 Aend="Line 13" (7.5) Bend="" [] (0.0) CalledNum=026XXXXXXXX () CallingNum=073XXXXXXXX () Internal=0 Time=2 AState=Idle
1536086611mS CMCallEvt: 13.19.1 240225 Q931 Trunk:13 CHAN=4: StateChange: END=A CMCSIdle->CMCSDialInitiated
1536086611mS CMTARGET: 13.19.1 240225 Q931 Trunk:13 CHAN=4: LOOKUP CALL ROUTE: type=2 called_party=026XXXXXXXX sub= calling=073XXXXXXXX dir=in complete=1 ses=0
1536086611mS CMTARGET: 13.19.1 240225 Q931 Trunk:13 CHAN=4: SET BESTMATCH: length 0 vs -1 match= dest=VM:Start
1536086611mS CMTARGET: 13.19.1 240225 Q931 Trunk:13 CHAN=4: SET BESTMATCH: length 9 vs 0 match=026XXXXXXXX dest=VM:Start
1536086612mS CMCallEvt: Priority hike: call 240225 priority 0->1
1536086612mS CMTARGET: 13.19.1 240225 Q931 Trunk:13 CHAN=4: LOOKUP ICR: DDI= CGPN=073XXXXXXXX (Destination VM:Start ) => CDPN=VM:Start
1536086612mS CMTARGET: 13.19.1 240225 Q931 Trunk:13 CHAN=4: ADD TARGET (N): number=VM:Start type=2 depth=1 nobar=1 setorig=1 ses=0
1536086612mS CMTARGET: 13.19.1 240225 Q931 Trunk:13 CHAN=4: ADD VM TARGET
1536086612mS CMTARGET: **** 13.19.1 240225 Q931 Trunk:13 CHAN=4: MakeVoicemailTarget pbx=<null> local=1 type=1
1536086613mS CMCallEvt: 0.718663.0 -1 BaseEP: NEW CMEndpoint f4e4081c TOTAL NOW=6 CALL_LIST=2
1536086613mS CMTARGET: 0.718663.0 240225 RAS.0: ADD PRIMARY
1536086613mS CMTARGET: 13.19.1 240225 Q931 Trunk:13 CHAN=4: ADD VM TARGET: SUCCEEDED
1536086613mS CMTARGET: 13.19.1 240225 Q931 Trunk:13 CHAN=4: INITIAL TARGETING SUCCEEDED
1536086613mS CMTARGET: 13.19.1 240225 Q931 Trunk:13 CHAN=4: GetNoAnswerTimer:24
1536086614mS CMCallEvt: 13.19.1 240225 Q931 Trunk:13 CHAN=4: StateChange: END=A CMCSDialInitiated->CMCSDialled
1536086614mS CMLineTx: v=13
CMProceeding
Line: type=Q931Line 13 Call: lid=13 id=19 in=1
BChan: slot=0 chan=4
1536086614mS CMCallEvt: 0.718662.0 240225 TargetingEP: StateChange: END=B CMCSIdle->CMCSOffering
1536086615mS CMCallEvt: 0.718663.0 240225 RAS.0: StateChange: END=T CMCSIdle->CMCSOffering
1536086615mS CMExtnEvt: RAS: CMExtnHandler::SetCurrent( id: 0->718663 )
1536086616mS CMMap: a=21.42 b=1.254 T
1536086617mS CMCallEvt: 0.718663.0 240225 RAS.0: StateChange: END=T CMCSOffering->CMCSConnReq
1536086617mS CMCallEvt: 0.718662.0 240225 TargetingEP: RequestEnd 0.718663.0 240225 RAS.0
1536086617mS CMTARGET: 13.19.1 240225 Q931 Trunk:13 CHAN=4: CancelTimer CMTCNoAnswerTimeout
1536086618mS CMExtnEvt: v=1011 State, new=Connected old=Idle,0,0,RAS
1536086618mS CMCallEvt: 13.19.1 240225 Q931 Trunk:13 CHAN=4: StateChange: END=A CMCSDialled->CMCSOGConnReq
1536086619mS CMLineTx: v=13
CMConnect
Line: type=Q931Line 13 Call: lid=13 id=19 in=1
BChan: slot=0 chan=4
Display [++fStart,]
1536086619mS CMCallEvt: 0.718662.0 -1 TargetingEP: StateChange: END=X CMCSOffering->CMCSDelete
1536086619mS CMCallEvt: 0.718662.0 -1 BaseEP: DELETE CMEndpoint f4dfbd80 TOTAL NOW=5 CALL_LIST=2
1536086620mS CD: CALL: 13.19.1 BState=Connected Cut=3 Music=0.0 Aend="Line 13" (7.5) Bend="Start(Start)" [VoiceMail] (21.42) CalledNum=Start () CallingNum=073XXXXXXXX () Internal=0 Time=12 AState=Connected
1536086621mS ISDNL3Evt: v=13 stacknum=13 State, new=DiscReq, old=Delivered id=718655
1536086622mS ISDNL3Evt: v=13 stacknum=13 State, new=ICProceeding, old=Present id=19
1536086622mS ISDNL3Evt: v=13 stacknum=13 State, new=ConnReq, old=ICProceeding id=19
1536086622mS PRN: Config Write Wake Up
1536086622mS CMMap: PCG::MapBChan pcp[92]b1r0 cp_b f582ef88 other_cp_b 0 type CGTypeSimple
1536086623mS CMMap: PCG::MapBChan pcp[44]b1r0 cp_b f586de54 other_cp_b f582ef88 type CGTypeSimple
1536086623mS CMMap: a=7.5 b=21.42 M12
1536086696mS ISDNL3Evt: v=13 stacknum=13 State, new=Active, old=ConnReq id=19
1536086697mS CMLineRx: v=13
CMConnectAck
Line: type=Q931Line 13 Call: lid=13 id=19 in=1
1536086697mS CMCallEvt: 13.19.1 240225 Q931 Trunk:13 CHAN=4: StateChange: END=A CMCSOGConnReq->CMCSConnected
1536086697mS CMTARGET: 13.19.1 240225 Q931 Trunk:13 CHAN=4: ~CMTargetHandler f4ee95d0 ep f4efd188
1536086698mS CMCallEvt: 0.718663.0 240225 RAS.0: StateChange: END=B CMCSConnReq->CMCSConnected
1536086747mS ISDNL3Evt: v=13 stacknum=13 State, new=NullState, old=DiscReq id=718655
1536086748mS CMLineRx: v=13
CMReleaseComp
Line: type=Q931Line 13 Call: lid=0 id=718655 in=0
BChan: slot=0 chan=30

Can this be a firewall issue? Blocking the RTP streams only on certain calls from what it seems specific numbers? Sounds wierd.
Traffic: ISDN Multi to H323 Avaya 9608
Issue: Keeps ringing for the external source, silent for the reciever.