# A few clients with 1 way voice on inbound calls. Outbound seem fine
**URL:** https://forums.vitalpbx.org/t/a-few-clients-with-1-way-voice-on-inbound-calls-outbound-seem-fine/6028
**Category:** VitalPBX
**Created:** [February 5, 2026, 7:42pm UTC](https://forums.vitalpbx.org/t/a-few-clients-with-1-way-voice-on-inbound-calls-outbound-seem-fine/6028 "2026-02-05T19:42:14Z")
**Posts on this page:** 8
**Page:** 1
### Author:  [@mbspencer](https://forums.vitalpbx.org/u/mbspencer)
#### Post date: [February 5, 2026, 7:42pm UTC](https://forums.vitalpbx.org/t/a-few-clients-with-1-way-voice-on-inbound-calls-outbound-seem-fine/6028/1 "2026-02-05T19:42:14Z")
I have had a few clients complain that they have 1 way voice on inbound calls. The sometimes fix has been to wipe the phone and let it grab a config again, make sure Nat is set to keep alive etc. But it doesn’t always fix it.
My PBX has a public address and I have the remote sites in the firewall on the PBX as allowed.
What else may be causing this issue? Doesn’t happen all the time but when it starts, it seems to hang on. I thought about converting to TCP Transport. Has anyone else made that conversion and did it help? Any thoughts on why this is happening on my side. I have a location right now that has been fine for a couple of months, but yesterday started with the 1 way voice. 13ms ping times, no network issues. I did reboot their firewall this morning and waiting to see if that helped.
Any help would be appreciated.
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### Author:  [@mo10](https://forums.vitalpbx.org/u/mo10)
#### Post date: [February 6, 2026, 1:54pm UTC](https://forums.vitalpbx.org/t/a-few-clients-with-1-way-voice-on-inbound-calls-outbound-seem-fine/6028/2 "2026-02-06T13:54:12Z")
Most likely Firewall issue.
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### Author:  [@marian](https://forums.vitalpbx.org/u/marian)
#### Post date: [February 6, 2026, 7:43pm UTC](https://forums.vitalpbx.org/t/a-few-clients-with-1-way-voice-on-inbound-calls-outbound-seem-fine/6028/3 "2026-02-06T19:43:52Z")
Do you habe enougth rtp Ports configured in the pbx
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### Author:  [@mbspencer](https://forums.vitalpbx.org/u/mbspencer)
#### Post date: [February 6, 2026, 9:50pm UTC](https://forums.vitalpbx.org/t/a-few-clients-with-1-way-voice-on-inbound-calls-outbound-seem-fine/6028/4 "2026-02-06T21:50:11Z")
They are using the same firewall as other locations without and issue. But I will review that config just in case.
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### Author:  [@mbspencer](https://forums.vitalpbx.org/u/mbspencer)
#### Post date: [February 6, 2026, 9:53pm UTC](https://forums.vitalpbx.org/t/a-few-clients-with-1-way-voice-on-inbound-calls-outbound-seem-fine/6028/5 "2026-02-06T21:53:18Z")
RTP is 10000 to 20000 udp. I would think it would be enough.
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### Author:  [@mo10](https://forums.vitalpbx.org/u/mo10)
#### Post date: [February 7, 2026, 5:53am UTC](https://forums.vitalpbx.org/t/a-few-clients-with-1-way-voice-on-inbound-calls-outbound-seem-fine/6028/6 "2026-02-07T05:53:02Z")
Sip alg can help in 10% of the cases, and does harm in 90%.
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### Author:  [@marian](https://forums.vitalpbx.org/u/marian)
#### Post date: [February 7, 2026, 4:08pm UTC](https://forums.vitalpbx.org/t/a-few-clients-with-1-way-voice-on-inbound-calls-outbound-seem-fine/6028/7 "2026-02-07T16:08:53Z")
RTP Flood Protection in Firewall
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### Author:  [@system](https://forums.vitalpbx.org/u/system)
#### Post date: [March 9, 2026, 4:09pm UTC](https://forums.vitalpbx.org/t/a-few-clients-with-1-way-voice-on-inbound-calls-outbound-seem-fine/6028/8 "2026-03-09T16:09:48Z")
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