Rtpengine occupies too many ports

[Bob Bob]

Hi all, I'm encountering a tricky issue when using rtpengine to forward audio. Below is the problem description.

System version: Debian 13 amd64
rtpengine version: Version: 13.5.1.3+0~mr13.5.1.3, installed via Sipwise

rtpengine-ctl -ip 127.0.0.1:2224 list numsessions:

Current sessions own: 3

Current sessions foreign: 0

Current sessions total: 3
Current transcoded media: 0
Current sessions ipv4 only media: 0
Current sessions ipv6 only media: 0
Current sessions ip mixed media: 0

netstat -unlp | grep rtpengine | wc -l:

131262

Below are some key configurations; see the attachment for the complete configuration file.

table = 0

port-min = 20000

port-max = 39999

Why is the actual number of occupied ports so different from the number of active sessions?

Thank you.

[Bob Bob]

timeout = 60

silent-timeout = 3600

tos = 184

[Bob Bob]

The current architecture has one Kamailio using two rtpengines. Only one rtpengine is experiencing the issue of excessive port usage. Therefore, I believe it is not caused by Kamailio not calling rtpengine_delete().

Moreover, the rtpengine that is reporting the fault is deployed on the same server as Kamailio and connects directly via localhost.

[Bob Bob]

should I upgrade rtpengine to 13.5.1.27-1 to solve this?

[Richard Fuchs]

On 21/09/2026 04.02, Bob Bob wrote:
> should I upgrade rtpengine to 13.5.1.27-1 to solve this?

Upgrade to the newest version is always a good first step for
troubleshooting.

Although I have to admit, I find the number 131262 highly suspicious.
With a port range covering 20000 ports, you'd need at least 7 interfaces
to actually have that many ports open? What does `rtpengine-ctl list
interfaces` say?

Cheers

[Bob Bob]

Thanks for help.

Here is the result of `rtpengine-ctl list interfaces`

Interface 'PRIVATE' address '10.10.100.3' (IPv4)
 Port range: 20000 - 39999
 Ports used:   468 / 20000 (  2.3%)
 Packets/bytes/errors:
  Ingress:    901924642 / 154055232823 /          0
  Egress:     855338642 / 146572476452 /          8
 Packets lost/duplicates:          0 /          0
 MOS:    avg 4.3, packet loss avg   0%
 Jitter: avg 420 (measured -nan)
 RTT:    e2e 17072, dsct 10295

Interface 'PUBLIC' address '10.10.100.3' (IPv4)
 Port range: 20000 - 39999
 Ports used:   468 / 20000 (  2.3%)
 Packets/bytes/errors:
  Ingress:   1896271366 / 324210604025 /         14
  Egress:    1918801757 / 329000943631 /       4386
 Packets lost/duplicates:          0 /          0
 MOS:    avg 4.3, packet loss avg   0%
 Jitter: avg 217 (measured -nan)
 RTT:    e2e 23800, dsct 12905

So many ports are occupied, yet it doesn’t seem to affect audio transmission. It’s strange—what are these ports shown in the statistics?