RTP traffic outside of port range - no audio in either direction

FreePBX Networking
1

I got two (2) pfSense routers running in high availability and an odd issue.

When the primary router is acting as master packet capture shows RTP traffic between 10,000-20,000 as normal.

When the secondary router is acting as master, packet capture shows RTP traffic above 20,000 and there is no audio in either direction.

I don’t know why that is happening, but I tried to increase RTP port range to 10,000-40,000 (restarted FreePBX) and fixed the NAT rule to forward this new range to the PBX and I still cannot hear audio.

Does anyone have any idea what is happening?

Example from primary router packet capture. PBX IP is 10.3.0.6.

No. Time        Source      Dest.    Dest.Port Proto. Length Info
430	11.237808	10.3.0.6	23.29.31.59	10622	RTP	214	PT=ITU-T G.711 PCMU, SSRC=0x75183F7E, Seq=32541, Time=1236183024
431	11.260807	10.3.0.6	23.29.31.59	10622	RTP	214	PT=ITU-T G.711 PCMU, SSRC=0x75183F7E, Seq=32542, Time=1236183184
432	11.279599	10.3.0.6	23.29.31.59	10622	RTP	214	PT=ITU-T G.711 PCMU, SSRC=0x75183F7E, Seq=32543, Time=1236183344
433	11.298869	10.3.0.6	23.29.31.59	10622	RTP	214	PT=ITU-T G.711 PCMU, SSRC=0x75183F7E, Seq=32544, Time=1236183504
434	11.319698	10.3.0.6	23.29.31.59	10622	RTP	214	PT=ITU-T G.711 PCMU, SSRC=0x75183F7E, Seq=32545, Time=1236183664
435	11.339301	10.3.0.6	23.29.31.59	10622	RTP	214	PT=ITU-T G.711 PCMU, SSRC=0x75183F7E, Seq=32546, Time=1236183824
436	11.359628	10.3.0.6	23.29.31.59	10622	RTP	214	PT=ITU-T G.711 PCMU, SSRC=0x75183F7E, Seq=32547, Time=1236183984
437	11.380244	10.3.0.6	23.29.31.59	10622	RTP	214	PT=ITU-T G.711 PCMU, SSRC=0x75183F7E, Seq=32548, Time=1236184144
438	11.399577	10.3.0.6	23.29.31.59	10622	RTP	214	PT=ITU-T G.711 PCMU, SSRC=0x75183F7E, Seq=32549, Time=1236184304
439	11.420644	10.3.0.6	23.29.31.59	10622	RTP	214	PT=ITU-T G.711 PCMU, SSRC=0x75183F7E, Seq=32550, Time=1236184464
440	11.439584	10.3.0.6	23.29.31.59	10622	RTP	214	PT=ITU-T G.711 PCMU, SSRC=0x75183F7E, Seq=32551, Time=1236184624
441	11.460251	10.3.0.6	23.29.31.59	10622	RTP	214	PT=ITU-T G.711 PCMU, SSRC=0x75183F7E, Seq=32552, Time=1236184784
442	11.465357	23.29.31.59	10.3.0.6	11998	RTP	214	PT=ITU-T G.711 PCMU, SSRC=0xA8D84513, Seq=182, Time=29120
443	11.477851	10.3.0.6	23.29.31.59	10622	RTP	214	PT=ITU-T G.711 PCMU, SSRC=0x75183F7E, Seq=32553, Time=1236184944
444	11.485389	23.29.31.59	10.3.0.6	11998	RTP	214	PT=ITU-T G.711 PCMU, SSRC=0xA8D84513, Seq=183, Time=29280
445	11.487954	34.226.36.33	10.3.0.6	5060	SIP	633	Request: ACK sip:216.80.94.34:5060 |

Secondary router:

No. Time        Source      Dest.    Dest.Port Proto. Length Info
962	14.272737	10.3.0.6	23.29.31.59	21050	RTP	214	PT=ITU-T G.711 PCMU, SSRC=0x6CE91F89, Seq=27743, Time=1261503664
963	14.288532	23.29.31.59	10.3.0.6	15770	RTP	214	PT=ITU-T G.711 PCMU, SSRC=0x35D91D17, Seq=418, Time=66880
964	14.292832	10.3.0.6	23.29.31.59	21050	RTP	214	PT=ITU-T G.711 PCMU, SSRC=0x6CE91F89, Seq=27744, Time=1261503824
965	14.308521	23.29.31.59	10.3.0.6	15770	RTP	214	PT=ITU-T G.711 PCMU, SSRC=0x35D91D17, Seq=419, Time=67040
966	14.312800	10.3.0.6	23.29.31.59	21050	RTP	214	PT=ITU-T G.711 PCMU, SSRC=0x6CE91F89, Seq=27745, Time=1261503984
967	14.328545	23.29.31.59	10.3.0.6	15770	RTP	214	PT=ITU-T G.711 PCMU, SSRC=0x35D91D17, Seq=420, Time=67200
968	14.332745	10.3.0.6	23.29.31.59	21050	RTP	214	PT=ITU-T G.711 PCMU, SSRC=0x6CE91F89, Seq=27746, Time=1261504144
969	14.348505	23.29.31.59	10.3.0.6	15770	RTP	214	PT=ITU-T G.711 PCMU, SSRC=0x35D91D17, Seq=421, Time=67360
970	14.352831	10.3.0.6	23.29.31.59	21050	RTP	214	PT=ITU-T G.711 PCMU, SSRC=0x6CE91F89, Seq=27747, Time=1261504304
971	14.368543	23.29.31.59	10.3.0.6	15770	RTP	214	PT=ITU-T G.711 PCMU, SSRC=0x35D91D17, Seq=422, Time=67520
972	14.372782	10.3.0.6	23.29.31.59	21050	RTP	214	PT=ITU-T G.711 PCMU, SSRC=0x6CE91F89, Seq=27748, Time=1261504464
973	14.388517	23.29.31.59	10.3.0.6	15770	RTP	214	PT=ITU-T G.711 PCMU, SSRC=0x35D91D17, Seq=423, Time=67680
974	14.392788	10.3.0.6	23.29.31.59	21050	RTP	214	PT=ITU-T G.711 PCMU, SSRC=0x6CE91F89, Seq=27749, Time=1261504624
975	14.408522	23.29.31.59	10.3.0.6	15770	RTP	214	PT=ITU-T G.711 PCMU, SSRC=0x35D91D17, Seq=424, Time=67840
976	14.412823	10.3.0.6	23.29.31.59	21050	RTP	214	PT=ITU-T G.711 PCMU, SSRC=0x6CE91F89, Seq=27750, Time=1261504784
977	14.428510	23.29.31.59	10.3.0.6	15770	RTP	214	PT=ITU-T G.711 PCMU, SSRC=0x35D91D17, Seq=425, Time=68000
978	14.432808	10.3.0.6	23.29.31.59	21050	RTP	214	PT=ITU-T G.711 PCMU, SSRC=0x6CE91F89, Seq=27751, Time=1261504944
979	14.448538	23.29.31.59	10.3.0.6	15770	RTP	214	PT=ITU-T G.711 PCMU, SSRC=0x35D91D17, Seq=426, Time=68160
980	14.452902	10.3.0.6	23.29.31.59	21050	RTP	214	PT=ITU-T G.711 PCMU, SSRC=0x6CE91F89, Seq=27752, Time=1261505104
981	14.468510	23.29.31.59	10.3.0.6	15770	RTP	214	PT=ITU-T G.711 PCMU, SSRC=0x35D91D17, Seq=427, Time=68320
2

The “Dest.Port” you are seeing in the “Secondary router” logging is the port of the remote side. You have no control over the port range they will allocate from to receive media on, you only control your own range that you will receive media on.

3

Ahh I see.

I did increase the port range (the changes I mentioned in my first post did not properly propagate to the “secondary” router) and am getting inbound voice working, but outbound is not working. I will update this post if I find a complete resolution.

4

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